WorldWideScience

Sample records for current imaging techniques

  1. Current and emerging techniques in gastrointestinal imaging

    Directory of Open Access Journals (Sweden)

    McSweeney S

    2010-01-01

    Full Text Available This review is devoted to current and emerging techniques in gastrointestinal (GI imaging. It is divided into three sections focusing on areas that are both interesting and challenging: imaging of the small bowel and appendix, imaging of the colon and rectum and finally liver and pancreas in the upper abdomen. The first section covers cross-sectional imaging of the small bowel using the techniques of multidetector computed tomography (MDCT (including CT enterography and magnetic resonance imaging (MRI. The evaluation of mesenteric ischemia and GI tract bleeding using MDCT angiography is also reviewed. Current imaging practice in the evaluation of appendix is also reviewed and illustrated. The second section reviews CT and MR colonography and imaging of the rectum. It describes CT virtual colonoscopy (CTVC with emphasis on the advantages and disadvantages of the technique with discussion of the role of CTVC in screening. The intriguing topic of MR colonography (MRC is also reviewed. Imaging of the rectum with emphasis on imaging of rectal cancer is described with the roles of CT, MR, endoluminal ultrasound and positron emission tomography scanning discussed. The final section reviews current and emerging techniques in liver imaging with the role of ultrasound including contrast ultrasound, MDCT and MR (including contrast agents discussed. The new developments and applications of imaging of pancreatic disease are discussed with emphasis on the role of MDCT and MRI with gadolinium. This review highlights the current role and advancement of imaging techniques with new diagnostic and prognostic information pertinent to gastrointestinal disease continuing to emerge.

  2. Gastrointestinal tract imaging in children: current techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hiorns, Melanie P. [Great Ormond Street Hospital for Children, Radiology Department, London (United Kingdom)

    2011-01-15

    Imaging of the gastrointestinal (GI) tract in children continues to evolve, with new techniques, both radiological and non-radiological, being added to the repertoire. This article provides a summary of current imaging techniques of the GI tract (primarily the upper GI tract) and the relationship between those techniques. It covers the upper GI series and other contrast studies, US, CT and MRI. Note is also made of the contribution now made by capsule endoscopy (CE). Abdominal emergency imaging is not covered in this article. (orig.)

  3. Superresolution imaging: a survey of current techniques

    Science.gov (United States)

    Cristóbal, G.; Gil, E.; Šroubek, F.; Flusser, J.; Miravet, C.; Rodríguez, F. B.

    2008-08-01

    Imaging plays a key role in many diverse areas of application, such as astronomy, remote sensing, microscopy, and tomography. Owing to imperfections of measuring devices (e.g., optical degradations, limited size of sensors) and instability of the observed scene (e.g., object motion, media turbulence), acquired images can be indistinct, noisy, and may exhibit insuffcient spatial and temporal resolution. In particular, several external effects blur images. Techniques for recovering the original image include blind deconvolution (to remove blur) and superresolution (SR). The stability of these methods depends on having more than one image of the same frame. Differences between images are necessary to provide new information, but they can be almost unperceivable. State-of-the-art SR techniques achieve remarkable results in resolution enhancement by estimating the subpixel shifts between images, but they lack any apparatus for calculating the blurs. In this paper, after introducing a review of current SR techniques we describe two recently developed SR methods by the authors. First, we introduce a variational method that minimizes a regularized energy function with respect to the high resolution image and blurs. In this way we establish a unifying way to simultaneously estimate the blurs and the high resolution image. By estimating blurs we automatically estimate shifts with subpixel accuracy, which is inherent for good SR performance. Second, an innovative learning-based algorithm using a neural architecture for SR is described. Comparative experiments on real data illustrate the robustness and utilization of both methods.

  4. Pediatric imaging: Current and emerging techniques

    Directory of Open Access Journals (Sweden)

    Shenoy-Bhangle A

    2010-01-01

    Full Text Available Imaging has always been an important component of the clinical evaluation of pediatric patients. Rapid technological advances in imaging are making noninvasive evaluation of a wide range of pediatric diseases possible. Ultrasound and magnetic resonance imaging (MRI are two imaging modalities that do not involve ionizing radiation and are preferred imaging modalities in the pediatric population. Computed tomography (CT remains the imaging modality with the highest increase in utilization in children due to its widespread availability and rapid image acquisition. Emerging imaging applications to be discussed include MR urography, voiding urosonography with use of ultrasound contrast agents, CT dose reduction techniques, MR enterography for inflammatory bowel disease, and MR cine airway imaging.

  5. Image analysis technique applied to lock-exchange gravity currents

    OpenAIRE

    Nogueira, Helena; Adduce, Claudia; Alves, Elsa; Franca, Rodrigues Pereira Da; Jorge, Mario

    2013-01-01

    An image analysis technique is used to estimate the two-dimensional instantaneous density field of unsteady gravity currents produced by full-depth lock-release of saline water. An experiment reproducing a gravity current was performed in a 3.0 m long, 0.20 m wide and 0.30 m deep Perspex flume with horizontal smooth bed and recorded with a 25 Hz CCD video camera under controlled light conditions. Using dye concentration as a tracer, a calibration procedure was established for each pixel in th...

  6. Imaging fast calcium currents beyond the limitations of electrode techniques.

    Science.gov (United States)

    Jaafari, Nadia; De Waard, Michel; Canepari, Marco

    2014-09-16

    The current understanding of Ca(2+) channel function is derived from the use of the patch-clamp technique. In particular, the measurement of fast cellular Ca(2+) currents is routinely achieved using whole-cell voltage-clamp recordings. However, this experimental approach is not applicable to the study of local native Ca(2+) channels during physiological changes of membrane potential in complex cells, since the voltage-clamp configuration constrains the membrane potential to a given value. Here, we report for the first time to our knowledge that Ca(2+) currents from individual cells can be quantitatively measured beyond the limitations of the voltage-clamp approach using fast Ca(2+) imaging with low-affinity indicators. The optical measurement of the Ca(2+) current was correlated with the membrane potential, simultaneously measured with a voltage-sensitive dye to investigate the activation of Ca(2+) channels along the apical dendrite of the CA1 hippocampal pyramidal neuron during the back-propagation of an action potential. To validate the method, we analyzed the voltage dependence of high- and low-voltage-gated Ca(2+) channels. In particular, we measured the Ca(2+) current component mediated by T-type channels, and we investigated the mechanisms of recovery from inactivation of these channels. This method is expected to become a reference approach to investigate Ca(2+) channels in their native physiological environment.

  7. Chest trauma in children: current imaging guidelines and techniques.

    LENUS (Irish Health Repository)

    Moore, Michael A

    2011-09-01

    Given the heterogeneous nature of pediatric chest trauma, the optimal imaging approach is tailored to the specific patient. Chest radiography remains the most important imaging modality for initial triage. The decision to perform a chest computed tomography scan should be based on the nature of the trauma, the child\\'s clinical condition, and the initial radiographic findings, taking the age-related pretest probabilities of serious injury into account. The principles of as low as reasonably achievable and Image Gently should be followed. The epidemiology and pathophysiology, imaging techniques, characteristic findings, and evidence-based algorithms for pediatric chest trauma are discussed.

  8. Osteomyelitis: a review of currently used imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sammak, B.; Abd El Bagi, M; Al Shahed, M.; Al Nabulsi, J.; Youssef, B.; Al Thagafi, M. [Department of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Hamilton, D. [Department of Medical Physics, Riyadh Armed Forces Hospital (Saudi Arabia)

    1999-06-01

    Conventional radiographs remain the initial imaging modality involved in the diagnosis of osteomyelitis. Bone scintigraphy and its specific agents did not only eliminate the problems of inherent low sensitivity of conventional radiographs, but also increased the specificity to higher degrees. Spiral CT, on the other hand, has solved several diagnostic problems, such as osteomyelitis of the sterno-clavicular junction and hidden areas in the pelvic bones. Magnetic resonance imaging with its multiplanar capability, greater anatomic details and excellent soft tissue bone marrow contrast resolution has a significant role in surgical planning and limb preservation. Ultrasound and US-guided aspiration has recently been involved in the diagnosis and management of osteomyelitis with several advantages particularly in children. Our goal in this review is to outline the ability of various imaging techniques by comparing their strengths and weaknesses in the diagnosis of osteomyelitis. Finally, we suggest various imaging algorithms for specific clinical scenarios. Spondylitis and septic arthritis are not discussed in this review. (orig.) With 7 figs., 43 refs.

  9. Magnetic force microscopy/current contrast imaging: A new technique for internal current probing of ICs

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, A.N.; Cole, E.I. Jr.; Dodd, B.A.; Anderson, R.E.

    1993-09-01

    This invited paper describes recently reported work on the application of magnetic force microscopy (MFM) to image currents in IC conductors [1]. A computer model for MFM imaging of IC currents and experimental results demonstrating the ability to determine current direction and magnitude with a resolution of {approximately} 1 mA dc and {approximately} 1 {mu}A ac are presented. The physics of MFM signal generation and applications to current imaging and measurement are described.

  10. Current cardiac imaging techniques for detection of left ventricular mass

    Directory of Open Access Journals (Sweden)

    Celebi Aksuyek S

    2010-06-01

    Full Text Available Abstract Estimation of left ventricular (LV mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR and cardiovascular computed tomography (CCT are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test.

  11. Pectus excavatum: current imaging techniques and opportunities for dose reduction.

    Science.gov (United States)

    Sarwar, Zahir U; DeFlorio, Robert; O'Connor, Stephen C

    2014-08-01

    Pectus excavatum (PE) is the most common congenital chest wall deformity in children. It affects 1 in every 300-1000 live births with a male to female ratio of 5:1. Most of the patients present in their first year of life. During the teenage years, patients may have exercise intolerance and psychological strain because of their chest wall deformity. The Nuss and Ravitch procedures are established methods of surgical correction of PE. An index of severity known best as the Haller index, typically evaluated with computed tomography scan, when measuring greater than 3.2 is considered to indicate moderate or severe PE and is a prerequisite for third-party insurance reimbursement for these corrective procedures. This article reviews the clinical features of PE, the role of imaging, and the opportunities for radiation dose reduction.

  12. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Uei; Tan, Cher Heng [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong [Tan Tock Seng Hospital, Department of Cardiology, Singapore (Singapore)

    2014-08-28

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  13. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  14. Imaging Techniques in Psoriatic Arthritis: Update 2012-2014 on Current Status and Future Prospects.

    Science.gov (United States)

    Aleo, Elena; Migone, Stefania; Prono, Valentina; Barbieri, Francesca; Garlaschi, Giacomo; Cimmino, Marco A

    2015-11-01

    By providing additional and more sensitive information over clinical examination, imaging techniques are useful in the assessment of patients with psoriatic arthritis (PsA) and have been increasingly used to obtain additional clues to its pathogenesis. This review describes the current status and future development of conventional radiography, computed tomography, magnetic resonance imaging, positron emission tomography, and other novel techniques in the evaluation of PsA, with a focus on their use in diagnosing, monitoring, and predicting disease course and followup treatment response. The role and applications of ultrasonography are outside the scope and are reviewed elsewhere in these proceedings.

  15. Ultra-fast dynamic imaging: an overview of current techniques, their capabilities and future prospects

    Science.gov (United States)

    Altucci, C.; Velotta, R.; Marangos, J. P.

    2010-06-01

    In this review we attempt to sketch an overview of the various methods currently being used or under development to enable ultra-fast dynamic imaging of matter. We concentrate on those techniques which combine atomic scale spatial resolution and femtosecond or even sub-femtosecond temporal resolution. In part this review was inspired and informed by the material presented at the 'Ultrafast Dynamic Imaging II' workshop held in Ischia, Italy in April 2009, but we also have drawn on a wider background of material especially when discussing the emerging laser-based methods.

  16. Direct imaging of neural currents using ultra-low field magnetic resonance techniques

    Science.gov (United States)

    Volegov, Petr L.; Matlashov, Andrei N.; Mosher, John C.; Espy, Michelle A.; Kraus, Jr., Robert H.

    2009-08-11

    Using resonant interactions to directly and tomographically image neural activity in the human brain using magnetic resonance imaging (MRI) techniques at ultra-low field (ULF), the present inventors have established an approach that is sensitive to magnetic field distributions local to the spin population in cortex at the Larmor frequency of the measurement field. Because the Larmor frequency can be readily manipulated (through varying B.sub.m), one can also envision using ULF-DNI to image the frequency distribution of the local fields in cortex. Such information, taken together with simultaneous acquisition of MEG and ULF-NMR signals, enables non-invasive exploration of the correlation between local fields induced by neural activity in cortex and more `distant` measures of brain activity such as MEG and EEG.

  17. Acute gastrointestinal bleeding: emerging role of multidetector CT angiography and review of current imaging techniques.

    Science.gov (United States)

    Laing, Christopher J; Tobias, Terrence; Rosenblum, David I; Banker, Wade L; Tseng, Lee; Tamarkin, Stephen W

    2007-01-01

    Acute gastrointestinal bleeding is a common cause of hospitalization, morbidity, and mortality in the United States. The evaluation and treatment of acute gastrointestinal bleeding are complex and often require a multispecialty approach involving gastroenterologists, surgeons, internists, emergency physicians, and radiologists. The multitude of pathologic processes that can result in gastrointestinal bleeding, the length of the gastrointestinal tract, and the often intermittent nature of gastrointestinal bleeding further complicate patient evaluation. In addition, there are multiple imaging modalities and therapeutic interventions that are currently being used in the evaluation and treatment of acute gastrointestinal hemorrhage, each with its own strengths and weaknesses. Initial experience indicates that multidetector computed tomographic angiography is a promising first-line modality for the time-efficient, sensitive, and accurate diagnosis or exclusion of active gastrointestinal hemorrhage and may have a profound impact on the evaluation and subsequent treatment of patients who present with acute gastrointestinal bleeding.

  18. Non-invasive imaging techniques in assessing non-alcoholic fatty liver disease: a current status of available methods.

    Science.gov (United States)

    Lăpădat, A M; Jianu, I R; Ungureanu, B S; Florescu, L M; Gheonea, D I; Sovaila, S; Gheonea, I A

    2017-01-01

    Non-alcoholic fatty liver disease (NAFLD) is an ailment affecting and increasing a number of people worldwide diagnosed via non-invasive imaging techniques, at a time when a minimum harm caused by medical procedures is rightfully emphasized, more sought after, than ever before. Liver steatosis should not be taken lightly even if its evolution is largely benign as it has the potential to develop into non-alcoholic steatohepatitis (NASH) or even more concerning, hepatic cirrhosis, and hepatocellular carcinoma (HCC). Traditionally, liver biopsy has been the standard for diagnosing this particular liver disease, but nowadays, a consistent number of imagistic methods are available for diagnosing hepatosteatosis and choosing the one appropriate to the clinical context is the key. Although different in sensitivity and specificity when it comes to determining the hepatic fat fraction (FF), these imaging techniques possessing a diverse availability, operating difficulty, cost, and reproducibility are invaluable to any modern physician. Ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), elastography, and spectroscopy will be discussed in order to lay out the advantages and disadvantages of their diagnostic potential and application. Although imagistics has given physicians a valuable insight into the means of managing NAFLD, the current methods are far from perfect, but given the time, they will surely be improved and the use of liver biopsy will be completely removed.

  19. Comparison of advanced optical imaging techniques with current otolaryngology diagnostics for improved middle ear assessment (Conference Presentation)

    Science.gov (United States)

    Nolan, Ryan M.; Shelton, Ryan L.; Monroy, Guillermo L.; Spillman, Darold R.; Novak, Michael A.; Boppart, Stephen A.

    2016-02-01

    Otolaryngologists utilize a variety of diagnostic techniques to assess middle ear health. Tympanometry, audiometry, and otoacoustic emissions examine the mobility of the tympanic membrane (eardrum) and ossicles using ear canal pressure and auditory tone delivery and detection. Laser Doppler vibrometry provides non-contact vibrational measurement, and acoustic reflectometry is used to assess middle ear effusion using sonar. These technologies and techniques have advanced the field beyond the use of the standard otoscope, a simple tissue magnifier, yet the need for direct visualization of middle ear disease for superior detection, assessment, and management remains. In this study, we evaluated the use of portable optical coherence tomography (OCT) and pneumatic low-coherence interferometry (LCI) systems with handheld probe delivery to standard tympanometry, audiometry, otoacoustic emissions, laser Doppler vibrometry, and acoustic reflectometry. Comparison of these advanced optical imaging techniques and current diagnostics was conducted with a case study subject with a history of unilateral eardrum trauma. OCT and pneumatic LCI provide novel dynamic spatiotemporal structural data of the middle ear, such as the thickness of the eardrum and quantitative detection of underlying disease pathology, which could allow for more accurate diagnosis and more appropriate management than currently possible.

  20. Microwave Breast Imaging Techniques

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, Tonny

    2010-01-01

    This paper outlines the applicability of microwave radiation for breast cancer detection. Microwave imaging systems are categorized based on their hardware architecture. The advantages and disadvantages of various imaging techniques are discussed. The fundamental tradeoffs are indicated between v...

  1. Microwave Breast Imaging Techniques

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Rubæk, Tonny

    2010-01-01

    This paper outlines the applicability of microwave radiation for breast cancer detection. Microwave imaging systems are categorized based on their hardware architecture. The advantages and disadvantages of various imaging techniques are discussed. The fundamental tradeoffs are indicated between...

  2. Current concepts in maxillofacial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boeddinghaus, Rudolf [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: rboeddinghaus@perthradclinic.com.au; Whyte, Andy [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: awhyte@perthradclinic.com.au

    2008-06-15

    A review of state-of-the-art maxillofacial imaging is presented. Current imaging techniques include intra-oral radiographs, dental panoramic tomography, multidetector helical computed tomography, cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI). The commonest conditions encountered in clinical radiological practice are reviewed, including maxillofacial deformities, complicated dental impactions, maxillofacial trauma, jaw lesions (cysts, neoplasms, fibro-osseous lesions (FOLs) and infections), and temporomandibular joint pathology. Pre-operative assessment for dental implant placement is also briefly reviewed.

  3. Imaging techniques in microbiology.

    Science.gov (United States)

    Fung, D C; Theriot, J A

    1998-06-01

    Recent advances in optical imaging have dramatically expanded the capabilities of the light microscope and its usefulness in microbiology research. Some of these advances include improved fluorescent probes, better cameras, new techniques such as confocal and deconvolution microscopy, and the use of computers in imaging and image analysis. These new technologies have now been applied to microbiological problems with resounding success.

  4. Automated medical image segmentation techniques

    Directory of Open Access Journals (Sweden)

    Sharma Neeraj

    2010-01-01

    Full Text Available Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT and Magnetic resonance (MR imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images.

  5. Other imaging techniques.

    Science.gov (United States)

    Isard, H J

    1984-02-01

    Images of the breast can now be produced by five modalities: x-ray, heat, sound, light, and magnetism. X-ray mammography is generally accepted as the most accurate of these in the detection of breast cancer, and the standard by which the others are judged. Despite the obvious attraction of nonionizing techniques, the economic factor attendant on multiple studies requires consideration. Nuclear magnetic resonance (NMR) is currently being investigated in several clinics, but as yet there is no large series of documented cases. This report addresses itself to thermography, ultrasonography and diaphanography (transillumination). The unique characteristics of each and their respective roles in evaluation of the breast, particularly in the detection of breast cancer, will be discussed. When used in conjunction with mammography, potential advantages include: enhanced diagnostic accuracy, reduction of unnecessary surgery, and, in proven cases of breast cancer, prognostic capability. Thus far it has not been demonstrated that any of the nonionizing techniques can serve as a sole screening modality for breast cancer detection in asymptomatic women.

  6. Scalp imaging techniques

    Science.gov (United States)

    Otberg, Nina; Shapiro, Jerry; Lui, Harvey; Wu, Wen-Yu; Alzolibani, Abdullateef; Kang, Hoon; Richter, Heike; Lademann, Jürgen

    2017-05-01

    Scalp imaging techniques are necessary tools for the trichological practice and for visualization of permeation, penetration and absorption processes into and through the scalp and for the research on drug delivery and toxicology. The present letter reviews different scalp imaging techniques and discusses their utility. Moreover, two different studies on scalp imaging techniques are presented in this letter: (1) scalp imaging with phototrichograms in combination with laser scanning microscopy, and (2) follicular measurements with cyanoacrylate surface replicas and light microscopy in combination with laser scanning microscopy. The experiments compare different methods for the determination of hair density on the scalp and different follicular measures. An average terminal hair density of 132 hairs cm-2 was found in 6 Caucasian volunteers and 135 hairs cm-2 in 6 Asian volunteers. The area of the follicular orifices accounts to 16.3% of the skin surface on average measured with laser scanning microscopy images. The potential volume of the follicular infundibulum was calculated based on the laser scanning measurements and is found to be 4.63 mm3 per cm2 skin on average. The experiments show that hair follicles are quantitatively relevant pathways and potential reservoirs for topically applied drugs and cosmetics.

  7. [Tomodensitometry: current technique and perspectives].

    Science.gov (United States)

    Bousquet, J C

    1994-10-01

    The inventors of computed tomography were rewarded by the Nobel Prize for Medicine in 1979. This apparatus, now used routinely, is based on the physical principle of attenuation of x-rays combined with computerised calculation to generate a tomographic image of the human body. This article describes the components of computed tomography, the mode of acquisition, calculation and image reconstruction and the criteria of image quality and artefacts. Continuous rotation of the x-ray tube, now available on the latest machines, allows rapid 3D acquisition of raw data, largely eliminating movement artefacts, particularly those related to respiration. It is also possible to reconstitute images in a different plane from the plane of acquisition and to obtain 3D representations of the volume studied. The advantages and disadvantages of this recent technique are discussed.

  8. Nanorobotics current approaches and techniques

    CERN Document Server

    Ferreira, Antoine

    2013-01-01

    Nanorobot devices now perform a wide variety of tasks at the nanoscale in a wide variety of fields including but not limited to fields such as manufacturing, medicine, supply chain, biology, and outer space. Nanorobotics: Current Approaches and Techniques is a comprehensive overview of this interdisciplinary field with a wide ranging discussion that includes nano-manipulation and industrial nanorobotics, nanorobotics in biology and medicine, nanorobotic sensing, navigation and swarm behavior, and protein and DNA-based nanorobotics. Also included is the latest on topics such as bio-nano-actuators and propulsion and navigation of nanorobotic systems using magnetic fields. Nanorobotics: Current Approaches and Techniques is an ideal book for scientists, researchers, and engineers actively involved in applied and robotic research and development.

  9. Psoriatic arthritis: imaging techniques

    Directory of Open Access Journals (Sweden)

    E. Lubrano

    2012-06-01

    Full Text Available Imaging techniques to assess psoriatic arthritis (PsA include radiography, ultrasonography (US, magnetic resonance imaging (MRI, computed tomography (CT and bone scintigraphy. The radiographic hallmark of PsA is the combination of destructive changes (joint erosions, tuft resorption, osteolysis with bone proliferation (including periarticular and shaft periostitis, ankylosis, spur formation and non-marginal syndesmophytes. US has an increasing important role in the evaluation of PsA. In fact, power Doppler US is useful mainly for its ability to assess musculoskeletal (joints, tendons, entheses and cutaneous (skin and nails involvement, to monitor efficacy of therapy and to guide steroid injections at the level of inflamed joints, tendon sheaths and entheses. MRI allows direct visualization of inflammation in peripheral and axial joints, and peripheral and axial entheses, and has dramatically improved the possibilities for early diagnosis and objective monitoring of the disease process in PsA. MRI has allowed explaining the relationships among enthesitis, synovitis and osteitis in PsA, supporting a SpA pattern of inflammation where enthesitis is the primary target of inflammation. CT has little role in assessment of peripheral joints, but it may be useful in assessing elements of spine disease. CT accuracy is similar to MRI in assessment of erosions in sacroiliac joint involvement, but CT is not as effective in detecting synovial inflammation. Bone scintigraphy lacks specificity and is now supplanted with US and MRI techniques.

  10. Current techniques for visualizing RNA in cells

    Science.gov (United States)

    Mannack, Lilith V.J.C.; Eising, Sebastian; Rentmeister, Andrea

    2016-01-01

    Labeling RNA is of utmost interest, particularly in living cells, and thus RNA imaging is an emerging field. There are numerous methods relying on different concepts ranging from hybridization-based probes, over RNA-binding proteins to chemo-enzymatic modification of RNA. These methods have different benefits and limitations. This review aims to outline the current state-of-the-art techniques and point out their benefits and limitations. PMID:27158473

  11. Image processing techniques for acoustic images

    Science.gov (United States)

    Murphy, Brian P.

    1991-06-01

    The primary goal of this research is to test the effectiveness of various image processing techniques applied to acoustic images generated in MATLAB. The simulated acoustic images have the same characteristics as those generated by a computer model of a high resolution imaging sonar. Edge detection and segmentation are the two image processing techniques discussed in this study. The two methods tested are a modified version of the Kalman filtering and median filtering.

  12. IMAGE ENHANCEMENT USING IMAGE FUSION AND IMAGE PROCESSING TECHNIQUES

    OpenAIRE

    Arjun Nelikanti

    2015-01-01

    Principle objective of Image enhancement is to process an image so that result is more suitable than original image for specific application. Digital image enhancement techniques provide a multitude of choices for improving the visual quality of images. Appropriate choice of such techniques is greatly influenced by the imaging modality, task at hand and viewing conditions. This paper will provide a combination of two concepts, image fusion by DWT and digital image processing techniques. The e...

  13. Radiologic imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Bushong, S.C. (Dept. of Radiology, Baylor College of Medicine, Houston, TX (US)); Eastman, T.R. (Agfagavert Inc., Irving, TX (US))

    1990-01-01

    The authors focus on the subject of clinical radiographic technique. Emphasizing correct radiographic technique, it's heavily illustrated with radiographs that demonstrate proper exposure and show what happens when exposure variables are changed. A key feature is a discussion and evaluation of radiographic technique charts. Basic technique charts are provided for every body part examined.

  14. Simultaneous multislice (SMS) imaging techniques

    NARCIS (Netherlands)

    Barth, M.; Breuer, F.; Koopmans, P.J.; Norris, David Gordon; Poser, B.A.

    2016-01-01

    Simultaneous multislice imaging (SMS) using parallel image reconstruction has rapidly advanced to become a major imaging technique. The primary benefit is an acceleration in data acquisition that is equal to the number of simultaneously excited slices. Unlike in-plane parallel imaging this can have

  15. Hybrid ultrasound imaging techniques (fusion imaging).

    Science.gov (United States)

    Sandulescu, Daniela Larisa; Dumitrescu, Daniela; Rogoveanu, Ion; Saftoiu, Adrian

    2011-01-07

    Visualization of tumor angiogenesis can facilitate non-invasive evaluation of tumor vascular characteristics to supplement the conventional diagnostic imaging goals of depicting tumor location, size, and morphology. Hybrid imaging techniques combine anatomic [ultrasound, computed tomography (CT), and/or magnetic resonance imaging (MRI)] and molecular (single photon emission CT and positron emission tomography) imaging modalities. One example is real-time virtual sonography, which combines ultrasound (grayscale, colour Doppler, or dynamic contrast harmonic imaging) with contrast-enhanced CT/MRI. The benefits of fusion imaging include an increased diagnostic confidence, direct comparison of the lesions using different imaging modalities, more precise monitoring of interventional procedures, and reduced radiation exposure.

  16. Current Trends in Sinonasal Imaging.

    Science.gov (United States)

    Huang, Benjamin Y; Senior, Brent A; Castillo, Mauricio

    2015-11-01

    As endoscopic sinus surgery (ESS) has evolved since its introduction to the United States, so has technology for imaging the sinonasal cavities. Although imaging is most frequently performed for evaluating chronic sinusitis refractory to medical therapy, its uses have expanded beyond inflammatory sinus disease. Multidetector Computed Tomography is the current workhorse for both diagnosis and preoperative planning in prospective ESS patients, while MR imaging remains a complementary tool for evaluating suspected tumors or intracranial and orbital complications of rhinosinusitis. In this article, the authors review current trends and potential future directions in the use of these modalities for sinus imaging.

  17. Technical Note: Phantom study to evaluate the dose and image quality effects of a computed tomography organ-based tube current modulation technique

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, Diksha; Schmidt, Taly Gilat, E-mail: taly.gilat-schmidt@marquette.edu [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53201 (United States); Crotty, Dominic J.; Stevens, Grant M. [GE Healthcare, Waukesha, Wisconsin 53188 (United States)

    2015-11-15

    Purpose: This technical note quantifies the dose and image quality performance of a clinically available organ-dose-based tube current modulation (ODM) technique, using experimental and simulation phantom studies. The investigated ODM implementation reduces the tube current for the anterior source positions, without increasing current for posterior positions, although such an approach was also evaluated for comparison. Methods: Axial CT scans at 120 kV were performed on head and chest phantoms on an ODM-equipped scanner (Optima CT660, GE Healthcare, Chalfont St. Giles, England). Dosimeters quantified dose to breast, lung, heart, spine, eye lens, and brain regions for ODM and 3D-modulation (SmartmA) settings. Monte Carlo simulations, validated with experimental data, were performed on 28 voxelized head phantoms and 10 chest phantoms to quantify organ dose and noise standard deviation. The dose and noise effects of increasing the posterior tube current were also investigated. Results: ODM reduced the dose for all experimental dosimeters with respect to SmartmA, with average dose reductions across dosimeters of 31% (breast), 21% (lung), 24% (heart), 6% (spine), 19% (eye lens), and 11% (brain), with similar results for the simulation validation study. In the phantom library study, the average dose reduction across all phantoms was 34% (breast), 20% (lung), 8% (spine), 20% (eye lens), and 8% (brain). ODM increased the noise standard deviation in reconstructed images by 6%–20%, with generally greater noise increases in anterior regions. Increasing the posterior tube current provided similar dose reduction as ODM for breast and eye lens, increased dose to the spine, with noise effects ranging from 2% noise reduction to 16% noise increase. At noise equal to SmartmA, ODM increased the estimated effective dose by 4% and 8% for chest and head scans, respectively. Increasing the posterior tube current further increased the effective dose by 15% (chest) and 18% (head

  18. [Current techniques in tonsil surgery].

    Science.gov (United States)

    Coromina Isern, Jordi; Esteller Moré, Eduard

    2010-12-01

    In recent years, consolidation of tonsillar hypertrophy as the principal surgical procedure has led to the emergence of new techniques. Most aim to reduce volume (tonsillectomy or tonsil reduction). These techniques have considerably decreased intra- and postoperative hemorrhages and pain intensity. The present article describes the mechanisms and the advantages and disadvantages of the various techniques, including electro-dissection using electrical scalpels, reduction using a microdebrider, ultrasonic scalpel, radiofrequency (with its different variations) and CO(2) laser. When techniques that reduce tonsil volume are used, the possibility of recurrence of the tonsillar hypertrophy is high if less than 85% of the tonsil is removed. There is also a considerable possibility of infection of the remaining tonsils, whichever technique is used, and therefore these techniques are not valid in the case of repetitive tonsillitis. Recently, alternatives to classical adenoidectomy using adenoid curette have also appeared. Bleeding can be minimized by using a microdebrider, radiofrequency or a blood coagulator. We also discuss the concept of partial adenoidectomy, which is preferred in patients at risk of velopharyngeal insufficiency.

  19. Review of advanced imaging techniques

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2012-01-01

    Full Text Available Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images ("optical biopsies" at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These advanced imaging modalities have exciting diagnostic potential and introduce new opportunities in pathology. Therefore, it is important that pathology informaticists understand these advanced imaging techniques and the impact they have on pathology. This paper reviews several recently developed microscopic techniques, including diffraction-limited methods (e.g., confocal microscopy, 2-photon microscopy, 4Pi microscopy, and spatially modulated illumination microscopy and subdiffraction techniques (e.g., photoactivated localization microscopy, stochastic optical reconstruction microscopy, and stimulated emission depletion microscopy. This article serves as a primer for pathology informaticists, highlighting the fundamentals and applications of advanced optical imaging techniques.

  20. Eye Redness Image Processing Techniques

    Science.gov (United States)

    Adnan, M. R. H. Mohd; Zain, Azlan Mohd; Haron, Habibollah; Alwee, Razana; Zulfaezal Che Azemin, Mohd; Osman Ibrahim, Ashraf

    2017-09-01

    The use of photographs for the assessment of ocular conditions has been suggested to further standardize clinical procedures. The selection of the photographs to be used as scale reference images was subjective. Numerous methods have been proposed to assign eye redness scores by computational methods. Image analysis techniques have been investigated over the last 20 years in an attempt to forgo subjective grading scales. Image segmentation is one of the most important and challenging problems in image processing. This paper briefly outlines the comprehensive of image processing and the implementation of image segmentation in eye redness.

  1. Submucosal tunneling techniques: current perspectives

    Directory of Open Access Journals (Sweden)

    Kobara H

    2014-04-01

    Full Text Available Hideki Kobara,1 Hirohito Mori,1 Kazi Rafiq,2 Shintaro Fujihara,1 Noriko Nishiyama,1 Maki Ayaki,1 Tatsuo Yachida,1 Tae Matsunaga,1 Johji Tani,1 Hisaaki Miyoshi,1 Hirohito Yoneyama,1 Asahiro Morishita,1 Makoto Oryu,1 Hisakazu Iwama,3 Tsutomu Masaki1 1Department of Gastroenterology and Neurology, 2Department of Pharmacology, 3Life Science Research Center, Faculty of Medicine, Kagawa University, Miki-cho, Kita-Gun, Kagawa, Japan Abstract: Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments. Keywords: submucosal endoscopy, submucosal tunneling method, natural orifice transluminal endoscopic surgery, peroral endoscopic myotomy, gastrointestinal subepithelial tumor, functional and motility disorders

  2. EDITORIAL: Imaging Systems and Techniques Imaging Systems and Techniques

    Science.gov (United States)

    Giakos, George; Yang, Wuqiang; Petrou, M.; Nikita, K. S.; Pastorino, M.; Amanatiadis, A.; Zentai, G.

    2011-10-01

    This special feature on Imaging Systems and Techniques comprises 27 technical papers, covering essential facets in imaging systems and techniques both in theory and applications, from research groups spanning three different continents. It mainly contains peer-reviewed articles from the IEEE International Conference on Imaging Systems and Techniques (IST 2011), held in Thessaloniki, Greece, as well a number of articles relevant to the scope of this issue. The multifaceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment, and the technological revolution; there is an urgent need to address and propose dynamic and innovative solutions to problems that tend to be either complex and static or rapidly evolving with a lot of unknowns. For instance, exploration of the engineering and physical principles of new imaging systems and techniques for medical applications, remote sensing, monitoring of space resources and enhanced awareness, exploration and management of natural resources, and environmental monitoring, are some of the areas that need to be addressed with urgency. Similarly, the development of efficient medical imaging techniques capable of providing physiological information at the molecular level is another important area of research. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, using high resolution and high selectivity nanoimaging techniques, can play an important role in the diagnosis and treatment of cancer, as well as provide efficient drug-delivery imaging solutions for disease treatment with increased sensitivity and specificity. On the other hand, technical advances in the development of efficient digital imaging systems and techniques and tomographic devices operating on electric impedance tomography, computed tomography, single-photon emission and positron emission tomography detection principles are anticipated to have a significant impact on a

  3. Hybrid ultrasound imaging techniques(fusion imaging)

    Institute of Scientific and Technical Information of China (English)

    Daniela Larisa Sandulescu; Daniela Dumitrescu; Ion Rogoveanu; Adrian Saftoiu

    2011-01-01

    Visualization of tumor angiogenesis can facilitate noninvasive evaluation of tumor vascular characteristics to supplement the conventional diagnostic imaging goals of depicting tumor location,size,and morphology.Hybrid imaging techniques combine anatomic [ultrasound,computed tomography(CT),and/or magnetic resonance imaging(MRI)] and molecular(single photon emission CT and positron emission tomography)imaging modalities.One example is real-time virtual sonography,which combines ultrasound(grayscale,colour Doppler,or dynamic contrast harmonic imaging)with contrast-enhanced CT/MRI.The benefits of fusion imaging include an increased diagnostic confidence,direct comparison of the lesions using different imaging modalities,more precise monitoring of interventional procedures,and reduced radiation exposure.

  4. Molecular imaging: current status and emerging strategies

    Energy Technology Data Exchange (ETDEWEB)

    Pysz, M.A. [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA (United States); Gambhir, S.S. [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA (United States); Departments of Bioengineering and Materials Science and Engineering, Stanford University, Stanford, CA (United States); Willmann, J.K., E-mail: willmann@stanford.ed [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, CA (United States)

    2010-07-15

    In vivo molecular imaging has a great potential to impact medicine by detecting diseases in early stages (screening), identifying extent of disease, selecting disease- and patient-specific treatment (personalized medicine), applying a directed or targeted therapy, and measuring molecular-specific effects of treatment. Current clinical molecular imaging approaches primarily use positron-emission tomography (PET) or single photon-emission computed tomography (SPECT)-based techniques. In ongoing preclinical research, novel molecular targets of different diseases are identified and, sophisticated and multifunctional contrast agents for imaging these molecular targets are developed along with new technologies and instrumentation for multi-modality molecular imaging. Contrast-enhanced molecular ultrasound (US) with molecularly-targeted contrast microbubbles is explored as a clinically translatable molecular imaging strategy for screening, diagnosing, and monitoring diseases at the molecular level. Optical imaging with fluorescent molecular probes and US imaging with molecularly-targeted microbubbles are attractive strategies as they provide real-time imaging, are relatively inexpensive, produce images with high spatial resolution, and do not involve exposure to ionizing irradiation. Raman spectroscopy/microscopy has emerged as a molecular optical imaging strategy for ultrasensitive detection of multiple biomolecules/biochemicals with both in vivo and ex vivo versatility. Photoacoustic imaging is a hybrid of optical and US techniques involving optically-excitable molecularly-targeted contrast agents and quantitative detection of resulting oscillatory contrast agent movement with US. Current preclinical findings and advances in instrumentation, such as endoscopes and microcatheters, suggest that these molecular imaging methods have numerous potential clinical applications and will be translated into clinical use in the near future.

  5. EDITORIAL: Imaging systems and techniques Imaging systems and techniques

    Science.gov (United States)

    Yang, Wuqiang; Giakos, George; Nikita, Konstantina; Pastorino, Matteo; Karras, Dimitrios

    2009-10-01

    The papers in this special issue focus on providing the state-of-the-art approaches and solutions to some of the most challenging imaging areas, such as the design, development, evaluation and applications of imaging systems, measuring techniques, image processing algorithms and instrumentation, with an ultimate aim of enhancing the measurement accuracy and image quality. This special issue explores the principles, engineering developments and applications of new imaging systems and techniques, and encourages broad discussion of imaging methodologies, shaping the future and identifying emerging trends. The multi-faceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment and technological evolution. There is an urgent need to address new problems, which tend to be either static but complex, or dynamic, e.g. rapidly evolving with time, with many unknowns, and to propose innovative solutions. For instance, the battles against cancer and terror, monitoring of space resources and enhanced awareness, management of natural resources and environmental monitoring are some of the areas that need to be addressed. The complexity of the involved imaging scenarios and demanding design parameters, e.g. speed, signal-to-noise ratio (SNR), specificity, contrast, spatial resolution, scatter rejection, complex background and harsh environments, necessitate the development of a multi-functional, scalable and efficient imaging suite of sensors, solutions driven by innovation, and operation on diverse detection and imaging principles. Efficient medical imaging techniques capable of providing physiological information at the molecular level present another important research area. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, and using high-resolution, high-selectivity nano-imaging methods, quantum dots, nanoparticles, biomarkers, nanostructures, nanosensors, micro-array imaging chips

  6. Multisensor image fusion techniques in remote sensing

    Science.gov (United States)

    Ehlers, Manfred

    Current and future remote sensing programs such as Landsat, SPOT, MOS, ERS, JERS, and the space platform's Earth Observing System (Eos) are based on a variety of imaging sensors that will provide timely and repetitive multisensor earth observation data on a global scale. Visible, infrared and microwave images of high spatial and spectral resolution will eventually be available for all parts of the earth. It is essential that efficient processing techniques be developed to cope with the large multisensor data volumes. This paper discusses data fusion techniques that have proved successful for synergistic merging of SPOT HRV, Landsat TM and SIR-B images. It is demonstrated that these techniques can be used to improve rectification accuracies, to depicit greater cartographic detail, and to enhance spatial resolution in multisensor image data sets.

  7. Genitourinary imaging: Current and emerging applications

    Directory of Open Access Journals (Sweden)

    O′ Donoghue P

    2010-01-01

    Full Text Available This review discusses the current and emerging techniques in urinary tract imaging. Recent technical advances and novel discoveries make this an exciting but challenging time for urinary tract imaging. The first section describes the imaging of the adrenal gland which has made great strides in the last decade, the current major adrenal imaging modalities as well as new applications are discussed with particular attention to the role of imaging in the incidentally detected adrenal lesion. In the second section the role of ultrasound, computed tomography (CT and magnetic resonance (MR in evaluation of the renal tract are discussed with the new technical advances leading to earlier detection and characterization of renal lesions. Complementary to this is the emerging role of CT and MR urography in assessment of the urinary tract and bladder in contrast to the demise of plain film studies/intravenous urography. The role of CT angiography in assessment of the renal vasculature is also discussed. The third section discusses the role of prostate imaging in the diagnosis, staging and management of prostate cancer. Transrectal ultrasonography, can be used to guide biopsy, CT is frequently used in staging, with bone scintigraphy and positron emission tomography having roles in advanced disease. Currently, all imaging modalities, especially MR are evolving to improve disease detection and staging. The final section discusses the recently encountered adverse reaction of nephrogenic systemic fibrosis in patients post gadolinium-enhanced MRI and how to help prevent this adverse reaction.

  8. Genitourinary imaging: current and emerging applications.

    Science.gov (United States)

    O' Donoghue, P M; McSweeney, S E; Jhaveri, K

    2010-01-01

    This review discusses the current and emerging techniques in urinary tract imaging. Recent technical advances and novel discoveries make this an exciting but challenging time for urinary tract imaging. The first section describes the imaging of the adrenal gland which has made great strides in the last decade, the current major adrenal imaging modalities as well as new applications are discussed with particular attention to the role of imaging in the incidentally detected adrenal lesion. In the second section the role of ultrasound, computed tomography (CT) and magnetic resonance (MR) in evaluation of the renal tract are discussed with the new technical advances leading to earlier detection and characterization of renal lesions. Complementary to this is the emerging role of CT and MR urography in assessment of the urinary tract and bladder in contrast to the demise of plain film studies/intravenous urography. The role of CT angiography in assessment of the renal vasculature is also discussed. The third section discusses the role of prostate imaging in the diagnosis, staging and management of prostate cancer. Transrectal ultrasonography, can be used to guide biopsy, CT is frequently used in staging, with bone scintigraphy and positron emission tomography having roles in advanced disease. Currently, all imaging modalities, especially MR are evolving to improve disease detection and staging. The final section discusses the recently encountered adverse reaction of nephrogenic systemic fibrosis in patients post gadolinium-enhanced MRI and how to help prevent this adverse reaction.

  9. Image Segmentation by Using Threshold Techniques

    CERN Document Server

    Al-amri, Salem Saleh; D., Khamitkar S

    2010-01-01

    This paper attempts to undertake the study of segmentation image techniques by using five threshold methods as Mean method, P-tile method, Histogram Dependent Technique (HDT), Edge Maximization Technique (EMT) and visual Technique and they are compared with one another so as to choose the best technique for threshold segmentation techniques image. These techniques applied on three satellite images to choose base guesses for threshold segmentation image.

  10. Raman Imaging Techniques and Applications

    CERN Document Server

    2012-01-01

    Raman imaging has long been used to probe the chemical nature of a sample, providing information on molecular orientation, symmetry and structure with sub-micron spatial resolution. Recent technical developments have pushed the limits of micro-Raman microscopy, enabling the acquisition of Raman spectra with unprecedented speed, and opening a pathway to fast chemical imaging for many applications from material science and semiconductors to pharmaceutical drug development and cell biology, and even art and forensic science. The promise of tip-enhanced raman spectroscopy (TERS) and near-field techniques is pushing the envelope even further by breaking the limit of diffraction and enabling nano-Raman microscopy.

  11. Wavelet Based Image Denoising Technique

    Directory of Open Access Journals (Sweden)

    Sachin D Ruikar

    2011-03-01

    Full Text Available This paper proposes different approaches of wavelet based image denoising methods. The search for efficient image denoising methods is still a valid challenge at the crossing of functional analysis and statistics. In spite of the sophistication of the recently proposed methods, most algorithms have not yet attained a desirable level of applicability. Wavelet algorithms are useful tool for signal processing such as image compression and denoising. Multi wavelets can be considered as an extension of scalar wavelets. The main aim is to modify the wavelet coefficients in the new basis, the noise can be removed from the data. In this paper, we extend the existing technique and providing a comprehensive evaluation of the proposed method. Results based on different noise, such as Gaussian, Poisson’s, Salt and Pepper, and Speckle performed in this paper. A signal to noise ratio as a measure of the quality of denoising was preferred.

  12. Imaging Techniques for Microwave Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Donne, T. [FOM-Institute for Plasma Physics Rijnhuizen, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Luhmann Jr, N.C. [University of California, Davis, CA 95616 (United States); Park, H.K. [POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Tobias, B.

    2011-07-01

    Advances in microwave technology have made it possible to develop a new generation of microwave imaging diagnostics for measuring the parameters of magnetic fusion devices. The most prominent of these diagnostics is electron cyclotron emission imaging (ECE-I). After the first generation of ECE-I diagnostics utilized at the TEXT-U, RTP and TEXTOR tokamaks and the LHD stellarator, new systems have recently come into operation on ASDEX-UG and DIII-D, soon to be followed by a system on KSTAR. The DIII-D and KSTAR systems feature dual imaging arrays that observe different parts of the plasma. The ECE-I diagnostic yields two-dimensional movies of the electron temperature in the plasma and has given already new insights into the physics of sawtooth oscillations, tearing modes and edge localized modes. Microwave Imaging Reflectometry (MIR) is used on LHD to measure electron density fluctuations. A pilot MIR system has been tested at TEXTOR and, based on the promising results, a new system is now under design for KSTAR. The system at TEXTOR was used to measure the plasma rotation velocity. The system at KSTAR and also the one on LHD will be/are used for measuring the profile of the electron density fluctuations in the plasma. Other microwave imaging diagnostics are phase imaging interferometry, and imaging microwave scattering. The emphasis in this paper will be largely focused on ECE-I. First an overview of the advances in microwave technology are discussed, followed by a description of a typical ECE-I system along with some typical experimental results. Also the utilization of imaging techniques in other types of microwave diagnostics will be briefly reviewed. This document is composed of the slides of the presentation. (authors)

  13. Different Image Segmentation Techniques for Dental Image Extraction

    Directory of Open Access Journals (Sweden)

    R. Bala Subramanyam

    2014-07-01

    Full Text Available Image segmentation is the process of partitioning a digital image into multiple segments and often used to locate objects and boundaries (lines, curves etc.. In this paper, we have proposed image segmentation techniques: Region based, Texture based, Edge based. These techniques have been implemented on dental radiographs and gained good results compare to conventional technique known as Thresholding based technique. The quantitative results show the superiority of the image segmentation technique over three proposed techniques and conventional technique.

  14. Angular Differential Imaging: a Powerful High-Contrast Imaging Technique

    Energy Technology Data Exchange (ETDEWEB)

    Marois, C; Lafreniere, D; Doyon, R; Macintosh, B; Nadeau, D

    2005-11-07

    Angular differential imaging is a high-contrast imaging technique that reduces speckle noise from quasi-static optical aberrations and facilitates the detection of faint nearby companions. A sequence of images is acquired with an altitude/azimuth telescope, the instrument rotator being turned off. This keeps the instrument and telescope optics aligned, stabilizes the instrumental PSF and allows the field of view to rotate with respect to the instrument. For each image, a reference PSF obtained from other images of the sequence is subtracted. All residual images are then rotated to align the field and are median combined. Observed performances are reported for Gemini Altair/NIRI data. Inside the speckle dominated region of the PSF, it is shown that quasi-static PSF noise can be reduced by a factor {approx}5 for each image subtraction. The combination of all residuals then provides an additional gain of the order of the square root of the total number of images acquired. To our knowledge, this is the first time an acquisition strategy and reduction pipeline designed for speckle attenuation and high contrast imaging is demonstrated to significantly get better detection limits with longer integration times at all angular separations. A PSF noise attenuation of 100 was achieved from 2-hour long sequences of images of Vega, reaching a 5-sigma contrast of 20 magnitudes for separations greater than 7''. This technique can be used with currently available instruments to search for {approx} 1 M{sub Jup} exoplanets with orbits of radii between 50 and 300 AU around nearby young stars. The possibility of combining the technique with other high-contrast imaging methods is briefly discussed.

  15. Neurophysiological imaging techniques in dementia.

    Science.gov (United States)

    Comi, G; Leocani, L

    1999-01-01

    Neurophysiological methods, such as electroencephalography (EEG) and event-related potentials, are useful tools in the investigation of brain cognitive function in normal and pathological conditions, with an excellent time resolution when compared to that of other functional imaging techniques. Advanced techniques using a high number of EEG channels also enable a good spatial resolution to be achieved. This, together with the possibility of integration with other anatomical and functional images, may increase the ability to localize brain functions. Spectral analysis of the resting EEG, which gives information on the integrity of the cortical and subcortical networks involved in the generation of cortical rhythms, has the limitation of low sensitivity and specificity for the type of cognitive impairment. In almost all types of dementia, decreased power of the high frequencies is indeed observed in mild stages, accompanied by increased power of the slow rhythms in the more advanced phases. The sensitivity for the detection of spectral abnormalities is improved by studying centroid modifications. More specific information on the type of dementia can be provided by coherence analysis of the resting EEG, a measure of functional cortico-cortical connections, which has different abnormal patterns in Alzheimer's disease, cerebrovascular dementia and dementia associated with multiple sclerosis. Another tool for improving the assessment of demented patients is the study of EEG activity related to particular tasks, such as event-related potentials and event-related desynchronization/synchronization of the EEG, which allow the study of brain activation during cognitive and motor tasks.

  16. Filtering Spam: Current Trends and Techniques

    Directory of Open Access Journals (Sweden)

    Geerthik S.

    2013-07-01

    Full Text Available This article gives an overview about latest trend and techniques in spam filtering. We analyzed the problems which is introduced by spam ,what spam actually do and how to measure the spam .This article mainly focuses on automated, non-interactive filters, with a broad review ranging from commercial implementations to ideas confined to current research papers. The solutions using both machine and non –machine learning approaches are reviewed and taxonomy of different approaches is presented. While a range of different techniques have and continue to be evaluated in academic research, heuristic and Bayesian filtering, along with its variants provide the greatest potential for future spam prevention.

  17. Image fusion theories, techniques and applications

    CERN Document Server

    Mitchell, HB

    2010-01-01

    This text provides a comprehensive introduction to the theories, techniques and applications of image fusion. It examines in detail many real-life examples of image fusion, including panchromatic sharpening and ensemble color image segmentation.

  18. Current Development of Breast-Speciifc Gamma Imaging (BSGI) Technique%乳腺专用伽玛显像(BSGI)技术的最新进展

    Institute of Scientific and Technical Information of China (English)

    孙达; 陈伟君

    2015-01-01

    Breast-Specific Gamma Imaging(BSGI)is an improved and optimizing nuclear medicine breast imaging technique on the basis of traditional gamma camera. It uses a high resolution, smal field-of-view scintil a detector. The detector is designed with 3 073 individual detector crystals and 48 position-sensitive photomultiplier tubes. The FOV of detector is 15 cm×20 cm, and optimal system resolution for breast imaging is 3 mm, can detect the diameter of only 2~3 mm smal lesions. BSGI has better sensitivity in detecting subcentimetre or nonpalpable breast cancer. The sensitivity for the diagnosis of breast cancer is high, not influenced by the density of the breast tissue, implants, architectural distortion or scars from prior surgery or radiation. So it is cal ed a high resolution, smal field-of-view breast-specific gamma camera.%乳腺专用伽玛显像(BSGI)是一种在传统伽玛照相机的基础上进行了优化的核医学显像技术,配置有高分辨率数字探测器,内置3072块晶体和48个光电倍增管。探测器的视野(FOV)为15 cm×20 cm,空间分辨率为3 mm,能探查到直径仅为2~3 mm的微小病灶,对亚厘米或不能触及的病灶有很高的应用价值,且不受乳腺致密组织、植入假体及术后瘢痕等因素的影响,对乳腺癌诊断的灵敏度较高。BSGI被称为小视野和高分辨率乳腺专用伽玛照相机。

  19. Tooling Techniques Enhance Medical Imaging

    Science.gov (United States)

    2012-01-01

    mission. The manufacturing techniques developed to create the components have yielded innovations advancing medical imaging, transportation security, and even energy efficiency.

  20. A Survey on Various Image Inpainting Techniques to Restore Image

    Directory of Open Access Journals (Sweden)

    Rajul Suthar,

    2014-02-01

    Full Text Available Image Inpainting or Image Restore is technique which is used to recover the damaged image and to fill the regions which are missing in original image in visually plausible way. Inpainting, the technique of modifying an image in an invisible form, it is art which is used from the early year. Applications of this technique include rebuilding of damaged photographs& films, removal of superimposed text, removal/replacement of unwanted objects, red eye correction, image coding. The main goal of the Inpainting is to change the damaged region in an image. In this paper we provide a review of different techniques used for image Inpainting. We discuss different inpainting techniques like Exemplar based image inpainting, PDE based image inpainting, texture synthesis based image inpainting, structural inpainting and textural inpainting.

  1. Robotic partial nephrectomy: current technique and outcomes.

    Science.gov (United States)

    Wang, Liang; Lee, Benjamin R

    2013-09-01

    Over the past decade, management of the T1 renal mass has focused on nephron-sparing surgery. Robotic partial nephrectomy has played an increasing role in the technique of preserving renal function by decreasing warm ischemia time, as well as optimizing outcomes of hemorrhage and fistula. Robot-assisted partial nephrectomy is designed to provide a minimally-invasive nephron-sparing surgical option utilizing reconstructive capability, decreasing intracorporeal suturing time, technical feasibility and safety. Ultimately, its benefits are resulting in its dissemination across institutions. Articulated instrumentation and three-dimensional vision facilitate resection, collecting system reconstruction and renorrhaphy, leading to decreased warm ischemia time while preserving oncological outcomes. The aim of the present review was to present our surgical sequence and technique, as well as review the current status of robot-assisted partial nephrectomy.

  2. Imaging Techniques in Endodontics: An Overview

    Science.gov (United States)

    Deepak, B. S.; Subash, T. S.; Narmatha, V. J.; Anamika, T.; Snehil, T. K.; Nandini, D. B.

    2012-01-01

    This review provides an overview of the relevance of imaging techniques such as, computed tomography, cone beam computed tomography, and ultrasound, to endodontic practice. Many limitations of the conventional radiographic techniques have been overcome by the newer methods. Advantages and disadvantages of various imaging techniques in endodontic practice are also discussed. PMID:22530184

  3. Radiotherapy in prostate cancer. Innovative techniques and current controversies

    Energy Technology Data Exchange (ETDEWEB)

    Geinitz, Hans [Krankenhaus der Barmherzigen Schwestern, Linz (Austria). Dept. of Radiation Oncology; Linz Univ. (Austria). Medical Faculty; Roach, Mack III [California Univ., San Francisco, CA (United States). Dept. of Radiation Oncology; Van As, Nicholas (ed.) [The Institute of Cancer Research, Sutton Surrey (United Kingdom)

    2015-04-01

    Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

  4. Imaging Techniques in Acute Heart Failure.

    Science.gov (United States)

    Pérez del Villar, Candelas; Yotti, Raquel; Bermejo, Javier

    2015-07-01

    In recent years, imaging techniques have revolutionized the diagnosis of heart failure. In patients with a clinical picture of acute decompensation, prognosis is largely determined by early implementation of general measures and treatment of the underlying cause. Given its diagnostic yield and portability, ultrasound has become an essential tool in the setting of acute heart failure, and is currently found in all medical departments involved in the care of the critically ill patient. Cardiac magnetic resonance and computed tomography allow detailed characterization of multiple aspects of cardiac structure and function that were previously unavailable. This helps guide and monitor many of the treatment decisions in the acute heart failure population in an entirely noninvasive way. This article aims to review the usefulness of the imaging techniques that are clinically relevant in the context of an episode of acute heart failure. We discuss the indications and limitations of these techniques in detail and describe the general principles for the appropriate interpretation of results. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Current State and Progress of Coronary Angiography in Multi-slice Spiral Computed Tomography Imaging Techniques%多排螺旋CT在冠状动脉成像技术中的现状与进展

    Institute of Scientific and Technical Information of China (English)

    胡斌; 徐文坚; 陈海松

    2012-01-01

    多层螺旋CT( mulil slice spiral CT,MSCT)技术的进步为无创性冠状动脉造影提供了广阔的前景,临床应用备受关注.特别是64层CT的出现,空间分辨率、时间分辨率大大提高,心电门控技术及三维后处理技术拓宽了CT在冠状动脉成像中的应用范围.本文阐述了CT在冠状动脉成像技术及影响因素,并对其现状及进展情况作综述.%Multi-detector row CT imaging techniques has great potential for development of noninvasive imaging of the coronary arteries. Coronary CT angiography in clinical utility field was paid highly attention to. Especially current computed tomography (64 slice CT) techniques combine high speed and spatial resolution with electrocardiography synchronization and three-dimensional post processing technology, the scope of coronary CT angiography was widen. This review article will describe the coronary angiography technology of multi-detector row CT and the factors as they relate to the current and future role of coronary CT angiography.

  6. Various diffusion magnetic resonance imaging techniques for pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Meng-Yue Tang; Xiao-Ming Zhang; Tian-Wu Chen; Xiao-Hua Huang

    2015-01-01

    Pancreatic cancer is one of the most common malignanttumors and remains a treatment-refractory cancer with a poor prognosis. Currently, the diagnosis of pancreatic neoplasm depends mainly on imaging and which methods are conducive to detecting small lesions. Compared to the other techniques, magnetic resonance imaging(MRI) has irreplaceable advantages and can provide valuable information unattainable with other noninvasive or minimally invasive imaging techniques. Advances in MR hardware and pulse sequence design have particularly improved the quality and robustness of MRI of the pancreas. Diffusion MR imaging serves as one of the common functional MRI techniques and is the only technique that can be used to reflect the diffusion movement of water molecules in vivo. It is generally known that diffusion properties depend on the characterization of intrinsic features of tissue microdynamics and microstructure. With the improvement of the diffusion models, diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique to the more complex. In this review, the various diffusion MRI techniques for pancreatic cancer are discussed, including conventional diffusion weighted imaging(DWI), multi-b DWI based on intra-voxel incoherent motion theory, diffusion tensor imaging and diffusion kurtosis imaging. The principles, main parameters, advantages and limitations of these techniques, as well as future directions for pancreatic diffusion imaging are also discussed.

  7. Review on Lossless Image Compression Techniques for Welding Radiographic Images

    Directory of Open Access Journals (Sweden)

    B. Karthikeyan

    2013-01-01

    Full Text Available Recent development in image processing allows us to apply it in different domains. Radiography image of weld joint is one area where image processing techniques can be applied. It can be used to identify the quality of the weld joint. For this the image has to be stored and processed later in the labs. In order to optimize the use of disk space compression is required. The aim of this study is to find a suitable and efficient lossless compression technique for radiographic weld images. Image compression is a technique by which the amount of data required to represent information is reduced. Hence image compression is effectively carried out by removing the redundant data. This study compares different ways of compressing the radiography images using combinations of different lossless compression techniques like RLE, Huffman.

  8. Imaging technique and current status of valvular heart disease using cardiac MRI; Untersuchungstechniken und Stellenwert der MRT bei der Diagnostik von Herzklappenerkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, J.; Sohns, J.M. [Universitaetsmedizin Goettingen, Georg-August-Universitaet, Institut fuer Diagnostische und Interventionelle Radiologie, Goettingen (Germany)

    2013-10-15

    The main indications for cardiac magnetic resonance imaging (MRI) in the evaluation of valvular heart disease are pathologies of the aortic and pulmonary valve. For mitral and tricuspid valve pathologies MRI is not the first line modality as these are usually well visualized by echocardiography. The advantages of MRI in valvular heart disease are a high reliability in the evaluation of ventricular volumes and function as well as the assessment of the perivalvular arterial or atrial structures. This reliability and the limitless access to any imaging plane partially compensates for the lower temporal and spatial resolution in comparison to echocardiography. In patients with congenital heart disease, cardiac MRI is established as a valuable diagnostic tool in daily clinical management, especially for the evaluation of pulmonary valve defects. Nevertheless, echocardiography remains the first-line diagnostic imaging tool for the foreseeable future. (orig.) [German] Die Untersuchung der Herzklappen in der MRT umfasst derzeit v. a. die Aorten- und Pulmonalisklappe. Pathologien der atrioventrikulaeren Klappen bilden demgegenueber nur selten die zentrale Fragestellung einer kardialen MRT-Untersuchung, da diese normalerweise einer echokardiographischen Untersuchung gut zugaenglich sind. Die Staerke der MRT ist die hohe Zuverlaessigkeit, mit der neben der Klappenmorphologie und -funktion die Funktionsparameter des jeweiligen Ventrikels und die Morphologie der nachgeschalteten Arterien bestimmt werden koennen. Dadurch kann die MRT die prinzipielle Schwaeche in der Orts- und Zeitaufloesung gegenueber der Echokardiographie teilweise kompensieren. Bei Patienten mit kongenitalen Herzvitien ist die MRT-basierte Klappendiagnostik fester Bestandteil des klinischen Managements. Das gilt besonders fuer die Evaluation der Pulmonalisklappe. Die Echokardiographie bleibt absehbar die Modalitaet der ersten Wahl fuer die Klappendiagnostik am Herzen. (orig.)

  9. A Shape Based Image Search Technique

    Directory of Open Access Journals (Sweden)

    Aratrika Sarkar

    2014-08-01

    Full Text Available This paper describes an interactive application we have developed based on shaped-based image retrieval technique. The key concepts described in the project are, imatching of images based on contour matching; iimatching of images based on edge matching; iiimatching of images based on pixel matching of colours. Further, the application facilitates the matching of images invariant of transformations like i translation ; ii rotation; iii scaling. The key factor of the system is, the system shows the percentage unmatched of the image uploaded with respect to the images already existing in the database graphically, whereas, the integrity of the system lies on the unique matching techniques used for optimum result. This increases the accuracy of the system. For example, when a user uploads an image say, an image of a mango leaf, then the application shows all mango leaves present in the database as well other leaves matching the colour and shape of the mango leaf uploaded.

  10. Imaging techniques: Nanoparticle atoms pinpointed

    Science.gov (United States)

    Farle, Michael

    2017-02-01

    The locations of atoms in a metallic alloy nanoparticle have been determined using a combination of electron microscopy and image simulation, revealing links between the particle's structure and magnetic properties. See Letter p.75

  11. Lorentz effect imaging of ionic currents in solution

    Science.gov (United States)

    Truong, Trong-Kha; Avram, Alexandru; Song, Allen W.

    2008-03-01

    Current functional MRI techniques relying on hemodynamic modulations are inherently limited in their ability to accurately localize neural activity in space and time. To address these limitations, we previously proposed a novel technique based on the Lorentz effect and demonstrated its ability to directly image minute electrical activity with a millisecond temporal resolution in gel phantoms containing conductive wires as well as in the human median nerve in vivo. To better characterize its contrast mechanism and ultimately further improve its sensitivity for in vivo applications, we now apply this technique to image ionic currents in solution, which serve as a better model for neural conduction in biological systems than the electronic currents in conductive wires used in previous phantom studies. Our results demonstrate that ionic currents with durations and current densities on the same order of magnitude as those induced by neuroelectric activity in nerve fibers and in the brain can be detected.

  12. Image processing techniques for remote sensing data

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.

    interpretation and for processing of scene data for autonomous machine perception. The technique of digital image processing are used for' automatic character/pattern recognition, industrial robots for product assembly and inspection, military recognizance... number of techniques have been suggested for restoration 37 of degraded images like inverse filter, wiener filter and constrained least square filter etc. The primary objective of scene analysis is to deduce from a single two dimensional image...

  13. Morphological Techniques for Medical Images: A Review

    Directory of Open Access Journals (Sweden)

    Isma Irum

    2012-08-01

    Full Text Available Image processing is playing a very important role in medical imaging with its versatile applications and features towards the development of computer aided diagnostic systems, automatic detections of abnormalities and enhancement in ultrasonic, computed tomography, magnetic resonance images and lots more applications. Medical images morphology is a field of study where the medical images are observed and processed on basis of geometrical and changing structures. Medical images morphological techniques has been reviewed in this study underlying the some human organ images, the associated diseases and processing techniques to address some anatomical problem detection. Images of Human brain, bone, heart, carotid, iris, lesion, liver and lung have been discussed in this study.

  14. Color Image Classification and Retrieval using Image mining Techniques

    Directory of Open Access Journals (Sweden)

    Dr.V.Mohan,

    2010-05-01

    Full Text Available Mining Image data is one of the essential features in the present scenario. Image data is the major one which plays vital role in every aspect of the systems like business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-BasedImage Retrieval (CBIR. CBIR systems perform retrieval based on the similarity defined in terms of extracted features with more objectiveness. But, the features of the query image alone will not be sufficient constraint for retrieving images. Hence, a new technique Color Image Classification and Retrieval using a Image Technique isproposed for improving user interaction with image retrieval systems by fully exploiting the similarity information.

  15. A New Technique for Digital Image Watermarking

    Institute of Scientific and Technical Information of China (English)

    Xiang-Sheng Wu

    2005-01-01

    In this paper, a new technique is proposed for rotation, scaling and translation (RST) invariant image watermarking based on log-polar mappings (LPM) and phase-only filtering (POF). The watermark is embedded in the LPM of Fourier magnitude spectrum of the original image, and a small portion of resulting LPM spectrum is used to calculate the watermark positions. This technique avoids computing inverse log-polar mapping (ILPM) to preserve the quality of the watermarked image, and avoids exhaustive search to save computation time and reduce false detection. Experimental results demonstrate that the digital watermarking technique is invariant and robust to rotation, scaling, and translation transformation.

  16. Image watermark detection techniques using quadtrees

    Directory of Open Access Journals (Sweden)

    Nidaa A. Abbas

    2015-07-01

    Full Text Available The quadtree, a hierarchical data structure for the representation of spatial information based on the principle of recursive decomposition, is widely used in digital image processing and computer graphics. This paper demonstrates the detection of invisible watermarked images generated by popular watermarking techniques, including CDMA, DCT, DWT, and Least Significant Bit (LSB using quadtree. Results corresponding to typical (512 × 512 pixel images show differences among these methods when they are used. Each time we use the same image, the original images and invisible watermarked image to test the four methods in conjunction with quadtree decomposition. In addition to the subjective method represented by quadtree, many objective evaluations such as Pearson correlation, mean square error (MSE, Structural SIMilarity Index (SSIM and false positive and false negative were used to give the comparison criteria between original and watermarked images. In results, the quadtree decomposition considered a promise subjective method to recognize among these watermark techniques.

  17. Terahertz Imaging Systems With Aperture Synthesis Techniques

    DEFF Research Database (Denmark)

    Krozer, Viktor; Löffler, Torsten; Dall, Jørgen

    2010-01-01

    imaging systems are reviewed in terms of the employed architecture and data processing strategies. Active multichannel measurement method is found to be promising for real-time applications among the various terahertz imaging techniques and is chosen as a basis for the imaging instruments presented......This paper presents the research and development of two terahertz imaging systems based on photonic and electronic principles, respectively. As part of this study, a survey of ongoing research in the field of terahertz imaging is provided focusing on security applications. Existing terahertz...... in this paper. An active system operation allows for a wide dynamic range, which is important for image quality. The described instruments employ a multichannel high-sensitivity heterodyne architecture and aperture filling techniques, with close to real-time image acquisition time. In the case of the photonic...

  18. Improvement of ultrasound speckle image velocimetry using image enhancement techniques.

    Science.gov (United States)

    Yeom, Eunseop; Nam, Kweon-Ho; Paeng, Dong-Guk; Lee, Sang Joon

    2014-01-01

    Ultrasound-based techniques have been developed and widely used in noninvasive measurement of blood velocity. Speckle image velocimetry (SIV), which applies a cross-correlation algorithm to consecutive B-mode images of blood flow has often been employed owing to its better spatial resolution compared with conventional Doppler-based measurement techniques. The SIV technique utilizes speckles backscattered from red blood cell (RBC) aggregates as flow tracers. Hence, the intensity and size of such speckles are highly dependent on hemodynamic conditions. The grayscale intensity of speckle images varies along the radial direction of blood vessels because of the shear rate dependence of RBC aggregation. This inhomogeneous distribution of echo speckles decreases the signal-to-noise ratio (SNR) of a cross-correlation analysis and produces spurious results. In the present study, image-enhancement techniques such as contrast-limited adaptive histogram equalization (CLAHE), min/max technique, and subtraction of background image (SB) method were applied to speckle images to achieve a more accurate SIV measurement. A mechanical sector ultrasound scanner was used to obtain ultrasound speckle images from rat blood under steady and pulsatile flows. The effects of the image-enhancement techniques on SIV analysis were evaluated by comparing image intensities, velocities, and cross-correlation maps. The velocity profiles and wall shear rate (WSR) obtained from RBC suspension images were compared with the analytical solution for validation. In addition, the image-enhancement techniques were applied to in vivo measurement of blood flow in human vein. The experimental results of both in vitro and in vivo SIV measurements show that the intensity gradient in heterogeneous speckles has substantial influence on the cross-correlation analysis. The image-enhancement techniques used in this study can minimize errors encountered in ultrasound SIV measurement in which RBCs are used as flow

  19. FPGA implementation of image enhancement techniques

    Science.gov (United States)

    Kumar, Karan; Jain, Aditya; Srivastava, Atul Kumar

    2009-06-01

    The objective of this paper is designing, modeling, simulation and synthesis of four Image Enhancement techniques on FPGA. Image Enhancement Algorithms can be classified as point processing Techniques, in which operation is done on pixel level and Spatial Filtering Technique, in which operation is performed within neighborhood of a pixel. Algorithms of all the techniques are studied and hardware circuits are realized for them. Then hardware logic is modeled in Matlab Simulink using Xilinx System Generator Block set and synthesized onto Virtex4 xc4vsx35-10ff668 FPGA chip. Using hardware co-simulation feature of FPGA kit, the algorithms developed are validated.

  20. A Proposed Multi Images Visible Watermarking Technique

    Directory of Open Access Journals (Sweden)

    Ruba G. Al-Zamil

    2016-04-01

    Full Text Available Visible watermarking techniques are proposed to secure digital data against unauthorized attacks. These techniques protect data from illegal access and use. In this work, a multi visible watermarking technique that allows embedding different types of markers into different types of background images has been proposed It also allows adding multiple markers on the same background image with different sizes, positions and opacity levels without any interference. The proposed technique improves the flexibility issues of visible watermarking and helps in increasing the security levels. A visible watermarking system is designed to implement the proposed technique. The system facilitates single and multiple watermarking as illustrated in the proposed technique. Experimental results indicate that the proposed technique applies visible watermarking successfully.

  1. SAR Image Segmentation using Vector Quantization Technique on Entropy Images

    CERN Document Server

    Kekre, H B; Sarode, Tanuja K

    2010-01-01

    The development and application of various remote sensing platforms result in the production of huge amounts of satellite image data. Therefore, there is an increasing need for effective querying and browsing in these image databases. In order to take advantage and make good use of satellite images data, we must be able to extract meaningful information from the imagery. Hence we proposed a new algorithm for SAR image segmentation. In this paper we propose segmentation using vector quantization technique on entropy image. Initially, we obtain entropy image and in second step we use Kekre's Fast Codebook Generation (KFCG) algorithm for segmentation of the entropy image. Thereafter, a codebook of size 128 was generated for the Entropy image. These code vectors were further clustered in 8 clusters using same KFCG algorithm and converted into 8 images. These 8 images were displayed as a result. This approach does not lead to over segmentation or under segmentation. We compared these results with well known Gray L...

  2. Alternating Current Heating Technique of Hollow Rod

    Institute of Scientific and Technical Information of China (English)

    Na Weisheng; Shi Tonghao

    1995-01-01

    @@ In recent years, wellbore heat tracing technique is widely used in development of high viscosity and high pour point crude oil. Theory and experiences show that wellbore heat tracing has obvious effect on increasing liquid yield of oil wells.

  3. Imaging of HCC—Current State of the Art

    Directory of Open Access Journals (Sweden)

    Christina Schraml

    2015-11-01

    Full Text Available Early diagnosis of hepatocellular carcinoma (HCC is crucial for optimizing treatment outcome. Ongoing advances are being made in imaging of HCC regarding detection, grading, staging, and also treatment monitoring. This review gives an overview of the current international guidelines for diagnosing HCC and their discrepancies as well as critically summarizes the role of magnetic resonance imaging (MRI and computed tomography (CT techniques for imaging in HCC. The diagnostic performance of MRI with nonspecific and hepatobililiary contrast agents and the role of functional imaging with diffusion-weighted imaging will be discussed. On the other hand, CT as a fast, cheap and easily accessible imaging modality plays a major role in the clinical routine work-up of HCC. Technical advances in CT, such as dual energy CT and volume perfusion CT, are currently being explored for improving detection, characterization and staging of HCC with promising results. Cone beam CT can provide a three-dimensional analysis of the liver with tumor and vessel characterization comparable to cross-sectional imaging so that this technique is gaining an increasing role in the peri-procedural imaging of HCC treated with interventional techniques.

  4. Compression Techniques for Image Processing Tasks

    OpenAIRE

    2013-01-01

    International audience; This article aims to present an overview of the different applications of data compression techniques in the image processing filed. Since some time ago, several research groups in the world have been developing various methods based on different data compression techniques to classify, segment, filter and detect digital images fakery. In this sense, it is necessary to analyze and clarify the relationship between different methods and put them into a framework to bette...

  5. IMAGE ANALYSIS BASED ON EDGE DETECTION TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    A method that incorporates edge detection technique, Markov Random field (MRF), watershed segmentation and merging techniques was presented for performing image segmentation and edge detection tasks. It first applies edge detection technique to obtain a Difference In Strength (DIS) map. An initial segmented result is obtained based on K-means clustering technique and the minimum distance. Then the region process is modeled by MRF to obtain an image that contains different intensity regions. The gradient values are calculated and then the watershed technique is used. DIS calculation is used for each pixel to define all the edges (weak or strong) in the image. The DIS map is obtained. This help as priority knowledge to know the possibility of the region segmentation by the next step (MRF), which gives an image that has all the edges and regions information. In MRF model,gray level l, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The segmentation results are improved by using watershed algorithm. After all pixels of the segmented regions are processed, a map of primitive region with edges is generated. The edge map is obtained using a merge process based on averaged intensity mean values. A common edge detectors that work on (MRF) segmented image are used and the results are compared. The segmentation and edge detection result is one closed boundary per actual region in the image.

  6. Lung Cancer Detection Using Image Processing Techniques

    Directory of Open Access Journals (Sweden)

    Mokhled S. AL-TARAWNEH

    2012-08-01

    Full Text Available Recently, image processing techniques are widely used in several medical areas for image improvement in earlier detection and treatment stages, where the time factor is very important to discover the abnormality issues in target images, especially in various cancer tumours such as lung cancer, breast cancer, etc. Image quality and accuracy is the core factors of this research, image quality assessment as well as improvement are depending on the enhancement stage where low pre-processing techniques is used based on Gabor filter within Gaussian rules. Following the segmentation principles, an enhanced region of the object of interest that is used as a basic foundation of feature extraction is obtained. Relying on general features, a normality comparison is made. In this research, the main detected features for accurate images comparison are pixels percentage and mask-labelling.

  7. Development of Wavelet Image Compression Technique to Particle Image Velocimetry

    Institute of Scientific and Technical Information of China (English)

    HuiLi

    2000-01-01

    In order to reduce the noise in the images and the physical storage,the wavelet-based image compression technique was applied to PIV processing in this paper,To study the effect of the wavelet bases,the standard PIV images were compressed by some known wavelet families,Daubechies,Coifman and Baylkin families with various compression ratios.It was found that a higher order wavelet base provided good compression performance for compressing PIV images,The error analysis of velocity field obtained indicated that the high compression ratio even up to 64:1,can be realized without losing significant flow information in PIV processing.The wavelet compression technique of PIV was applied to the experimental images of jet flow and showed excellent performance,A reduced number of erroneous vectors can be realized by varying compression ratio.It can say that the wavelet image compression technique is very effective in PIV system.

  8. Introduction to Magnetic Resonance Imaging Techniques

    OpenAIRE

    2009-01-01

    It is quite possible to acquire images with an MR scanner without understanding the principles behind it, but choosing the best parameters and methods, and interpreting images and artifacts, requires understanding. This text serves as an introduction to magnetic resonance imaging techniques. It is aimed at beginners in possession of only a minimal level of technical expertise, yet it introduces aspects of MR that are typically considered technically challenging. The notes were written in conn...

  9. Novel current monitoring techniques without shunt resistors

    Directory of Open Access Journals (Sweden)

    VODA Adriana

    2012-05-01

    Full Text Available Current measurement for automotiveelectrical actuator applications (with motors or valvesis necessary for appropriate control in many cases anda safety requirement in all cases: the control algorithmmay be dependent on the data but safety relevantfunctions will use it to determine possible over-current,over-temperature or failure conditions. This paperproposes an alternative method of monitoring thecurrent, without using sensors or current shunts.Instead, measurements are made on the motor in thedevelopment stages and low/high frequency variationsin the supply line are monitored, through low/highpassfilters, by available AD channels in the system.This results in cost reduction for the final product, byreducing hardware complexity.

  10. Statistical normalization techniques for magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Russell T. Shinohara

    2014-01-01

    Full Text Available While computed tomography and other imaging techniques are measured in absolute units with physical meaning, magnetic resonance images are expressed in arbitrary units that are difficult to interpret and differ between study visits and subjects. Much work in the image processing literature on intensity normalization has focused on histogram matching and other histogram mapping techniques, with little emphasis on normalizing images to have biologically interpretable units. Furthermore, there are no formalized principles or goals for the crucial comparability of image intensities within and across subjects. To address this, we propose a set of criteria necessary for the normalization of images. We further propose simple and robust biologically motivated normalization techniques for multisequence brain imaging that have the same interpretation across acquisitions and satisfy the proposed criteria. We compare the performance of different normalization methods in thousands of images of patients with Alzheimer's disease, hundreds of patients with multiple sclerosis, and hundreds of healthy subjects obtained in several different studies at dozens of imaging centers.

  11. Current concepts on imaging in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lecchi, Michela; Elisei, Federica; Lucignani, Giovanni [University of Milan, Institute of Radiological Sciences, Milan (Italy); San Paolo Hospital, Unit of Nuclear Medicine, Milan (Italy); Fossati, Piero [University of Milan, Institute of Radiological Sciences, Milan (Italy); CNAO Foundation, Milan (Italy); Orecchia, Roberto [University of Milan, Institute of Radiological Sciences, Milan (Italy); CNAO Foundation, Milan (Italy); European Institute of Oncology, Department of Radiation Oncology, Milan (Italy)

    2008-04-15

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy. (orig.)

  12. Current concepts on imaging in radiotherapy.

    Science.gov (United States)

    Lecchi, Michela; Fossati, Piero; Elisei, Federica; Orecchia, Roberto; Lucignani, Giovanni

    2008-04-01

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy.

  13. Progress in Circular SAR Imaging Technique

    Directory of Open Access Journals (Sweden)

    Hong Wen

    2012-06-01

    Full Text Available Circular SAR (CSAR is a newly developed all-directional high resolution 3D imaging mode in recent years, to satisfy the demand of finer observation. The National Key Laboratory of Science and Technology on Microwave Imaging, Institute of Electronics, Chinese Academy of Sciences (MITL, IECAS, had the first test flight experiment in Aug. 2011 with a P-band full polarization SAR system, and successfully obtained the all-directional high resolution circular SAR image. The initial results show that CSAR technique has the encouraging potential capability in the fields of high precision mapping, disaster evaluation, resource management and the other related applications. This paper firstly makes a detailed discussion on the progress of circular SAR imaging technique, which emphases on the several airborne experiments performed these years to show CSAR’s attractive features, then studies and illustrates the key techniques, and finally discusses the development trends.

  14. Automatic Image Registration Technique of Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    M. Wahed

    2013-03-01

    Full Text Available Image registration is a crucial step in most image processing tasks for which the final result is achieved from a combination of various resources. Automatic registration of remote-sensing images is a difficult task as it must deal with the intensity changes and variation of scale, rotation and illumination of the images. This paper proposes image registration technique of multi-view, multi- temporal and multi-spectral remote sensing images. Firstly, a preprocessing step is performed by applying median filtering to enhance the images. Secondly, the Steerable Pyramid Transform is adopted to produce multi-resolution levels of reference and sensed images; then, the Scale Invariant Feature Transform (SIFT is utilized for extracting feature points that can deal with the large variations of scale, rotation and illumination between images .Thirdly, matching the features points by using the Euclidian distance ratio; then removing the false matching pairs using the RANdom SAmple Consensus (RANSAC algorithm. Finally, the mapping function is obtained by the affine transformation. Quantitative comparisons of our technique with the related techniques show a significant improvement in the presence of large scale, rotation changes, and the intensity changes. The effectiveness of the proposed technique is demonstrated by the experimental results.

  15. Current MR imaging of renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Sae Lin; Sung, Seuk Jae [Dept. of Radiology, Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of)

    2016-08-15

    Renal cell carcinoma (RCC) consists of approximately 85-90% of renal masses, and its incidence is increasing due to widespread use of modern imaging modalities such as ultrasonography or computed tomography. Computed tomography has served an important role in the diagnosis and staging of RCC; however, recent advances in magnetic resonance imaging (MRI) techniques have considerably improved our ability to predict tumor biology beyond the morphologic assessment. Multiparametric MRI protocols include standard sequences tailored for the morphologic evaluation and acquisitions that provide information about the tumor microenvironment such as diffusion-weighted imaging and dynamic contrast-enhanced MRI. The role of multiparametric MRI in the evaluation of RCC now extends to preoperative characterization of RCC subtypes, histologic grade, and quantitative assessment of tumor response to targeted therapies in patients with metastatic disease. Herein, the clinical applications and recent advances in MRI applied to RCC are reviewed along with its merits and demerits. We aimed to review MRI techniques and image analysis that can improve the management of patients with RCC. Familiarity with the advanced MRI techniques and various imaging findings of RCC would also facilitate optimal clinical recommendations for patients.

  16. ENCRYPTION TECHNIQUES FOR SECURITY OF IMAGES

    Directory of Open Access Journals (Sweden)

    DR. DHIRENDRA MISHRA

    2014-01-01

    Full Text Available With the proliferation in technology and advent of internet the data has been digitized, so more emphasis is required for security while transmission and storage to save from unauthorized users. Protecting data in a safe and secure way which does not hamper the access of an authorized authority is difficult and interesting research problem. Many attempts have been made to solve this problem within the cryptographic community. Visual cryptography provides a very powerful technique by which one secret can be distributed into two or more images known as shares. When the shares on transparencies are superimposed exactly together, original secret can be discovered without computer involvement. Image cryptography disrupts the image so that no useful information is seen. The keys used for disruption is used in reverse manner to decrypt the image. This paper discusses the various encryption techniques for better image security and to protect them from unintentional user.

  17. [Our current technique for basic pterional craniotomy].

    Science.gov (United States)

    Kaneko, Nobuyuki; Kurita, Hiroki; Hino, Ken; Nagayama, Kazuki; Tsubokawa, Tamiji; Tanaka, Naoko; Fujitsuka, Mitsuyuki; Nakamura, Masanao; Shiokawa, Yoshiaki

    2005-09-01

    Pterional cnaniotomy is frequently used in neurosurgical practice, but still poses significant cosmetic and functional drawbacks. Here, we describe our modified technique to overcome such problems as the sterilization of the scalp without brush and razor, preemptive analgesia, preservation of the periostium for reconstruction, retrograde dissection of the temporal muscle, and complete sphenoidotomy using chisel or drills. The tips of our pterional craniotomy offer suitable size and depth of working field around the paraclinoidal regions, maintaining cosmetic satisfaction of the patients.

  18. An Effective Method of Image Retrieval using Image Mining Techniques

    CERN Document Server

    Kannan, A; Anbazhagan, N; 10.5121/ijma.2010.2402

    2010-01-01

    The present research scholars are having keen interest in doing their research activities in the area of Data mining all over the world. Especially, [13]Mining Image data is the one of the essential features in this present scenario since image data plays vital role in every aspect of the system such as business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-Based Image Retrieval (CBIR) which performs retrieval based on the similarity defined in terms of extracted features with more objectiveness. The drawback in CBIR is the features of the query image alone are considered. Hence, a new technique called Image retrieval based on optimum clusters is proposed for improving user interaction with image retrieval systems by fully exploiting the similarity information. The index is created by describing the images according to their color characteristics, with compact feature vectors, that represent typical co...

  19. Image fusion techniques in permanent seed implantation

    Directory of Open Access Journals (Sweden)

    Alfredo Polo

    2010-10-01

    Full Text Available Over the last twenty years major software and hardware developments in brachytherapy treatment planning, intraoperative navigation and dose delivery have been made. Image-guided brachytherapy has emerged as the ultimate conformal radiation therapy, allowing precise dose deposition on small volumes under direct image visualization. In thisprocess imaging plays a central role and novel imaging techniques are being developed (PET, MRI-MRS and power Doppler US imaging are among them, creating a new paradigm (dose-guided brachytherapy, where imaging is used to map the exact coordinates of the tumour cells, and to guide applicator insertion to the correct position. Each of these modalities has limitations providing all of the physical and geometric information required for the brachytherapy workflow.Therefore, image fusion can be used as a solution in order to take full advantage of the information from each modality in treatment planning, intraoperative navigation, dose delivery, verification and follow-up of interstitial irradiation.Image fusion, understood as the visualization of any morphological volume (i.e. US, CT, MRI together with an additional second morpholo gical volume (i.e. CT, MRI or functional dataset (functional MRI, SPECT, PET, is a well known method for treatment planning, verification and follow-up of interstitial irradiation. The term image fusion is used when multiple patient image datasets are registered and overlaid or merged to provide additional information. Fused images may be created from multiple images from the same imaging modality taken at different moments (multi-temporalapproach, or by combining information from multiple modalities. Quality means that the fused images should provide additional information to the brachythe rapy process (diagnosis and staging, treatment planning, intraoperative imaging, treatment delivery and follow-up that cannot be obtained in other ways. In this review I will focus on the role of

  20. Lossless image compression technique for infrared thermal images

    Science.gov (United States)

    Allred, Lloyd G.; Kelly, Gary E.

    1992-07-01

    The authors have achieved a 6.5-to-one image compression technique for thermal images (640 X 480, 1024 colors deep). Using a combination of new and more traditional techniques, the combined algorithm is computationally simple, enabling `on-the-fly' compression and storage of an image in less time than it takes to transcribe the original image to or from a magnetic medium. Similar compression has been achieved on visual images by virtue of the feature that all optical devices possess a modulation transfer function. As a consequence of this property, the difference in color between adjacent pixels is a usually small number, often between -1 and +1 graduations for a meaningful color scheme. By differentiating adjacent rows and columns, the original image can be expressed in terms of these small numbers. A simple compression algorithm for these small numbers achieves a four to one image compression. By piggy-backing this technique with a LZW compression or a fixed Huffman coding, an additional 35% image compression is obtained, resulting in a 6.5-to-one lossless image compression. Because traditional noise-removal operators tend to minimize the color graduations between adjacent pixels, an additional 20% reduction can be obtained by preprocessing the image with a noise-removal operator. Although noise removal operators are not lossless, their application may prove crucial in applications requiring high compression, such as the storage or transmission of a large number or images. The authors are working with the Air Force Photonics Technology Application Program Management office to apply this technique to transmission of optical images from satellites.

  1. IMAGE AUTHENTICATION TECHNIQUES AND ADVANCES SURVEY

    Directory of Open Access Journals (Sweden)

    Derroll David

    2015-10-01

    Full Text Available With the advanced technologies in the area of Engineering the World has become a smaller place and communication is in our finger tips. The multimedia sharing traffic through electronic media has increased tremendously in the recent years with the higher use of social networking sites. The statistics of amount of images uploaded in the internet per day is very huge. Digital Image security has become vulnerable due to increase transmission over non-secure channel and needs protection. Digital Images play a crucial role in medical and military images etc. and any tampering of them is a serious issue. Several approaches are introduced to authenticate multimedia images. These approaches can be categorized into fragile and semi-fragile watermarking, conventional cryptography and digital signatures based on the image content. The aim of this paper is to provide a comparative study and also a survey of emerging techniques for image authentication. The important requirements for an efficient image authentication system design are discussed along with the classification of image authentication into tamper detection, localization and reconstruction and robustness against image processing operation. Furthermore, the concept of image content based authentication is enlightened.

  2. CT myocardial perfusion imaging: current status and future directions.

    Science.gov (United States)

    Williams, M C; Newby, D E

    2016-08-01

    Computed tomography (CT) imaging of the heart has advanced rapidly, and it is now possible to perform a comprehensive assessment at a low radiation dose. CT myocardial perfusion imaging can provide additive information to CT coronary angiography, and is particularly useful in patients with heavily calcified coronary arteries or coronary artery stents. A number of protocols are now available for CT myocardial perfusion including static, dynamic, and dual-energy techniques. This review will discuss the current status of CT myocardial perfusion imaging, its clinical application, and future directions for this technology.

  3. Tablet surface characterisation by various imaging techniques

    DEFF Research Database (Denmark)

    Seitavuopio, Paulus; Rantanen, Jukka; Yliruusi, Jouko

    2003-01-01

    The aim of this study was to characterise tablet surfaces using different imaging and roughness analytical techniques including optical microscopy, scanning electron microscopy (SEM), laser profilometry and atomic force microscopy (AFM). The test materials compressed were potassium chloride (KCl......, but they do not provide quantitative information about surface roughness. Laser profilometry and AFM on the other hand provide quantitative roughness data from two different scales, laser profilometer from 1 mm and atomic force microscope from 90 microm scale. AFM is a powerful technique but other imaging...

  4. Retinal Image Simulation of Subjective Refraction Techniques.

    Science.gov (United States)

    Perches, Sara; Collados, M Victoria; Ares, Jorge

    2016-01-01

    Refraction techniques make it possible to determine the most appropriate sphero-cylindrical lens prescription to achieve the best possible visual quality. Among these techniques, subjective refraction (i.e., patient's response-guided refraction) is the most commonly used approach. In this context, this paper's main goal is to present a simulation software that implements in a virtual manner various subjective-refraction techniques--including Jackson's Cross-Cylinder test (JCC)--relying all on the observation of computer-generated retinal images. This software has also been used to evaluate visual quality when the JCC test is performed in multifocal-contact-lens wearers. The results reveal this software's usefulness to simulate the retinal image quality that a particular visual compensation provides. Moreover, it can help to gain a deeper insight and to improve existing refraction techniques and it can be used for simulated training.

  5. Red flag imaging techniques in Barrett's esophagus.

    Science.gov (United States)

    Saxena, Payal; Canto, Marcia Irene

    2013-07-01

    The key to detection and treatment of early neoplasia in Barrett's esophagus (BE) is thorough and careful inspection of the Barrett's segment. The greatest role for red flag techniques is to help identify neoplastic lesions for targeted biopsy and therapy. High-definition white light endoscopy (HD-WLE) can potentially improve endoscopic imaging of BE compared with standard endoscopy, but little scientific evidence supports this. The addition of autofluorescence imaging to HD-WLE and narrow band imaging increases sensitivity and the false-positive rate without significantly improving overall detection of BE-related neoplasia.

  6. A comparison of current prediction imaging programs

    Science.gov (United States)

    Smith, J. Dempsey; Thomas, Paul M.; Proffit, William R.

    2013-01-01

    To investigate perceived differences in the ability of current software to simulate the actual outcome of orthognathic surgery, we chose 10 difficult test cases with vertical discrepancies and “retreated” them using the actual surgical changes. Five programs—Dentofacial Planner Plus, Dolphin Imaging, Orthoplan, Quick Ceph Image, and Vistadent—were evaluated, by using both the default result and a refined result created with each program’s enhancement tools. Three panels (orthodontists, oral-maxillofacial surgeons, and laypersons) judged the default images and the retouched simulations by ranking the simulations in side-by-side comparisons and by rating each simulation relative to the actual outcome on a 6-point scale. For the default and retouched images, Dentofacial Planner Plus was judged the best default simulation 79% and 59% of the time, respectively, and its default images received the best (lowest) mean score (2.46) on the 6-point scale. It also scored best (2.26) when the retouched images were compared, but the scores for Dolphin Imaging (2.83) and Quick Ceph (3.03) improved. Retouching had little impact on the scores for the other programs. Although the results show differences in simulation ability, selecting a software package depends on many factors. Performance and ease of use, cost, compatibility, and other features such as image and practice management tools are all important considerations. Users concerned with operating system compatibility and practice management integration might want to consider Dolphin Imaging and Quick Ceph, the programs comprising the second tier. PMID:15127020

  7. Modern dental imaging: a review of the current technology and clinical applications in dental practice

    Energy Technology Data Exchange (ETDEWEB)

    Vandenberghe, Bart; Jacobs, Reinhilde [Katholieke Universiteit Leuven, Oral Imaging Centre, Faculty of Medicine, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Leuven (Belgium); Bosmans, Hilde [Katholieke Universiteit Leuven, Radiology Section, Department of Medical Diagnostic Sciences, Leuven (Belgium)

    2010-11-15

    A review of modern imaging techniques commonly used in dental practice and their clinical applications is presented. The current dental examinations consist of intraoral imaging with digital indirect and direct receptors, while extraoral imaging is divided into traditional tomographic/panoramic imaging and the more recently introduced cone beam computed tomography. Applications, limitations and current trends of these dental ''in-office'' radiographic techniques are discussed. (orig.)

  8. Quantitative Techniques in PET-CT Imaging

    NARCIS (Netherlands)

    Basu, Sandip; Zaidi, Habib; Holm, Soren; Alavi, Abass

    2011-01-01

    The appearance of hybrid PET/CT scanners has made quantitative whole body scanning of radioactive tracers feasible. This paper deals with the novel concepts for assessing global organ function and disease activity based on combined functional (PET) and structural (CT or MR) imaging techniques, their

  9. Application of Advanced Magnetic Resonance Imaging Techniques in Evaluation of the Lower Extremity

    Science.gov (United States)

    Braun, Hillary J.; Dragoo, Jason L.; Hargreaves, Brian A.; Levenston, Marc E.; Gold, Garry E.

    2012-01-01

    Synopsis This article reviews current magnetic resonance imaging techniques for imaging the lower extremity, focusing on imaging of the knee, ankle, and hip joints. Recent advancements in MRI include imaging at 7 Tesla, using multiple receiver channels, T2* imaging, and metal suppression techniques, allowing more detailed visualization of complex anatomy, evaluation of morphological changes within articular cartilage, and imaging around orthopedic hardware. PMID:23622097

  10. Image processing techniques for passive millimeter-wave imaging

    Science.gov (United States)

    Lettington, Alan H.; Gleed, David G.

    1998-08-01

    We present our results on the application of image processing techniques for passive millimeter-wave imaging and discuss possible future trends. Passive millimeter-wave imaging is useful in poor weather such as in fog and cloud. Its spatial resolution, however, can be restricted due to the diffraction limit of the front aperture. Its resolution may be increased using super-resolution techniques but often at the expense of processing time. Linear methods may be implemented in real time but non-linear methods which are required to restore missing spatial frequencies are usually more time consuming. In the present paper we describe fast super-resolution techniques which are potentially capable of being applied in real time. Associated issues such as reducing the influence of noise and improving recognition capability will be discussed. Various techniques have been used to enhance passive millimeter wave images giving excellent results and providing a significant quantifiable increase in spatial resolution. Examples of applying these techniques to imagery will be given.

  11. Hyperspectral imaging using the single-pixel Fourier transform technique

    Science.gov (United States)

    Jin, Senlin; Hui, Wangwei; Wang, Yunlong; Huang, Kaicheng; Shi, Qiushuai; Ying, Cuifeng; Liu, Dongqi; Ye, Qing; Zhou, Wenyuan; Tian, Jianguo

    2017-03-01

    Hyperspectral imaging technology is playing an increasingly important role in the fields of food analysis, medicine and biotechnology. To improve the speed of operation and increase the light throughput in a compact equipment structure, a Fourier transform hyperspectral imaging system based on a single-pixel technique is proposed in this study. Compared with current imaging spectrometry approaches, the proposed system has a wider spectral range (400-1100 nm), a better spectral resolution (1 nm) and requires fewer measurement data (a sample rate of 6.25%). The performance of this system was verified by its application to the non-destructive testing of potatoes.

  12. In vitro imaging techniques in neurodegenerative diseases.

    Science.gov (United States)

    Långström, Bengt; Andrén, Per E; Lindhe, Orjan; Svedberg, Marie; Hall, Håkan

    2007-01-01

    Neurodegeneration induces various changes in the brain, changes that may be investigated using neuroimaging techniques. The in vivo techniques are useful for the visualization of major changes, and the progressing abnormalities may also be followed longitudinally. However, to study and quantify minor abnormalities, neuroimaging of postmortem brain tissue is used. These in vitro methods are complementary to the in vivo techniques and contribute to the knowledge of pathophysiology and etiology of the neurodegenerative diseases. In vitro radioligand autoradiography has given great insight in the involvement of different neuronal receptor systems in these diseases. Data on the dopamine and cholinergic systems in neurodegeneration are discussed in this review. Also, the amyloid plaques are studied using in vitro radioligand autoradiography. Using one of the newer methods, imaging matrix-assisted laser desorption ionization mass spectrometry, the distribution of a large number of peptides and proteins may be detected in vitro on brain cryosections. In this overview, we describe in vitro imaging techniques in the neurodegenerative diseases as a complement to in vivo positron emission tomography and single photon emission computed tomography imaging.

  13. Combining calcium imaging with other optical techniques.

    Science.gov (United States)

    Canepari, Marco; Zecevic, Dejan; Vogt, Kaspar E; Ogden, David; De Waard, Michel

    2013-12-01

    Ca(2+) imaging is a commonly used approach for measuring Ca(2+) signals at high spatial resolution. The method is often combined with electrode recordings to correlate electrical and chemical signals or to investigate Ca(2+) signals following an electrical stimulation. To obtain information on electrical activity at the same spatial resolution, Ca(2+) imaging must be combined with membrane potential imaging. Similarly, stimulation of subcellular compartments requires photostimulation. Thus, combining Ca(2+) imaging with an additional optical technique facilitates the study of a number of physiological questions. The aim of this article is to introduce some basic principles regarding the combination of Ca(2+) imaging with other optical techniques. We discuss the design of the optics, the design of experimental protocols, the optical characteristics of Ca(2+) indicators used in combination with an optical probe, and the affinity of the Ca(2+) indicator in relation to the type of measurement. This information will enable the reader to devise an optimal strategy for combined optical experiments.

  14. Lessons from the masters current concepts in astronomical image processing

    CERN Document Server

    2013-01-01

    There are currently thousands of amateur astronomers around the world engaged in astrophotography at increasingly sophisticated levels. Their ranks far outnumber professional astronomers doing the same and their contributions both technically and artistically are the dominant drivers of progress in the field today. This book is a unique collaboration of individuals, all world-renowned in their particular area, and covers in detail each of the major sub-disciplines of astrophotography. This approach offers the reader the greatest opportunity to learn the most current information and the latest techniques directly from the foremost innovators in the field today.   The book as a whole covers all types of astronomical image processing, including processing of eclipses and solar phenomena, extracting detail from deep-sky, planetary, and widefield images, and offers solutions to some of the most challenging and vexing problems in astronomical image processing. Recognized chapter authors include deep sky experts su...

  15. Advances in Current Rating Techniques for Flexible Printed Circuits

    Science.gov (United States)

    Hayes, Ron

    2014-01-01

    Twist Capsule Assemblies are power transfer devices commonly used in spacecraft mechanisms that require electrical signals to be passed across a rotating interface. Flexible printed circuits (flex tapes, see Figure 2) are used to carry the electrical signals in these devices. Determining the current rating for a given trace (conductor) size can be challenging. Because of the thermal conditions present in this environment the most appropriate approach is to assume that the only means by which heat is removed from the trace is thru the conductor itself, so that when the flex tape is long the temperature rise in the trace can be extreme. While this technique represents a worst-case thermal situation that yields conservative current ratings, this conservatism may lead to overly cautious designs when not all traces are used at their full rated capacity. A better understanding of how individual traces behave when they are not all in use is the goal of this research. In the testing done in support of this paper, a representative flex tape used for a flight Solar Array Drive Assembly (SADA) application was tested by energizing individual traces (conductors in the tape) in a vacuum chamber and the temperatures of the tape measured using both fine-gauge thermocouples and infrared thermographic imaging. We find that traditional derating schemes used for bundles of wires do not apply for the configuration tested. We also determine that single active traces located in the center of a flex tape operate at lower temperatures than those on the outside edges.

  16. Image reconstruction techniques for high resolution human brain PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Comtat, C.; Bataille, F.; Sureau, F. [Service Hospitalier Frederic Joliot (CEA/DSV/DRM), 91 - Orsay (France)

    2006-07-01

    High resolution PET imaging is now a well established technique not only for small animal, but also for human brain studies. The ECAT HRRT brain PET scanner(Siemens Molecular Imaging) is characterized by an effective isotropic spatial resolution of 2.5 mm, about a factor of 2 better than for state-of-the-art whole-body clinical PET scanners. Although the absolute sensitivity of the HRRT (6.5 %) for point source in the center of the field-of-view is increased relative to whole-body scanner (typically 4.5 %) thanks to a larger co-polar aperture, the sensitivity in terms of volumetric resolution (75 (m{sup 3} at best for whole-body scanners and 16 (m{sup 3} for t he HRRT) is much lower. This constraint has an impact on the performance of image reconstruction techniques, in particular for dynamic studies. Standard reconstruction methods used with clinical whole-body PET scanners are not optimal for this application. Specific methods had to be developed, based on fully 3D iterative techniques. Different refinements can be added in the reconstruction process to improve image quality: more accurate modeling of the acquisition system, more accurate modeling of the statistical properties of the acquired data, anatomical side information to guide the reconstruction . We will present the performances these added developments for neuronal imaging in humans. (author)

  17. An LSB Method Of Image Steganographic Techniques

    Directory of Open Access Journals (Sweden)

    Lalit Kumar Jain

    2015-04-01

    Full Text Available The art of information hiding has received much attention in the recent years as security of information has become a big concern in this internet era. As sharing of sensitive information via a common communication channel has become inevitable. Steganography means hiding a secret message (the embedded message within a larger one (source cover in such a way that an observer cannot detect the presence of contents of the hidden message [1]. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the Internet [2]. This paper intends to give an overview of image Steganography, its uses and techniques. It also attempts to identify the requirements of a good Steganography algorithm and briefly reflects on which Steganography techniques are more suitable for which applications.

  18. Comparison of mouse mammary gland imaging techniques and applications: Reflectance confocal microscopy, GFP Imaging, and ultrasound

    Directory of Open Access Journals (Sweden)

    Cotarla Ion

    2008-01-01

    Full Text Available Abstract Background Genetically engineered mouse models of mammary gland cancer enable the in vivo study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue. Methods We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging. Results In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice. Conclusion In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary.

  19. Biometric identification using holographic radar imaging techniques

    Science.gov (United States)

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.; Kennedy, Mike O.; Foote, Harlen P.

    2007-04-01

    Pacific Northwest National Laboratory researchers have been at the forefront of developing innovative screening systems to enhance security and a novel imaging system to provide custom-fit clothing using holographic radar imaging techniques. First-of-a-kind cylindrical holographic imaging systems have been developed to screen people at security checkpoints for the detection of concealed, body worn, non-metallic threats such as plastic and liquid explosives, knifes and contraband. Another embodiment of this technology is capable of obtaining full sized body measurements in near real time without the person under surveillance removing their outer garments. Radar signals readily penetrate clothing and reflect off the water in skin. This full body measurement system is commercially available for best fitting ready to wear clothing, which was the first "biometric" application for this technology. One compelling feature of this technology for security biometric applications is that it can see effectively through disguises, appliances and body hair.

  20. Advanced imaging techniques in pediatric body MRI

    Energy Technology Data Exchange (ETDEWEB)

    Courtier, Jesse [UCSF Benioff Children' s Hospital, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology, Charleston, SC (United States); Anupindi, Sudha A. [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2017-05-15

    While there are many challenges specific to pediatric abdomino-pelvic MRI, many recent advances are addressing these challenges. It is therefore essential for radiologists to be familiar with the latest advances in MR imaging. Laudable efforts have also recently been implemented in many centers to improve the overall experience of pediatric patients, including the use of dedicated radiology child life specialists, MRI video goggles, and improved MR suite environments. These efforts have allowed a larger number of children to be scanned while awake, with fewer studies being done under sedation or anesthesia; this has resulted in additional challenges from patient motion and difficulties with breath-holding and tolerating longer scan times. In this review, we highlight common challenges faced in imaging the pediatric abdomen and pelvis and discuss the application of the newest techniques to address these challenges. Additionally, we highlight the newest advances in quantified imaging techniques, specifically in MR liver iron quantification. The techniques described in this review are all commercially available and can be readily implemented. (orig.)

  1. Current status of radionuclide scrotal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Holder, L.E.; Melloul, M.; Chen, D.

    1981-10-01

    Scrotal imaging with technetium-99m sodium pertechnetate consists of a radionuclide angiogram and static scrotal scans. Utilization of this study in patients presenting with an acute scrotum can dramatically reduce the number of surgical explorations for acute epididymitis. It can also aid in other aspects of differential diagnosis in patients presenting with either an acutely enlarged and/or painful scrotum or a scrotal mass. Ambiguities in previous descriptions of perfusion through the spermatic and extraspermatic cord vessels are described and distinguished from scrotal perfusion. The clinical and scintigraphic spectrum of testicular torsion, including spontaneous detorsion, early acute testicular torsion, midphase testicular torsion, and late phase or ''missed testicular torsion,'' is discussed and illustrated. The variety of patterns seen in acute epididymitis, including lateral and medial epididymal location, and focal epididymitis are described, as is the appearance of hydrocele as both a primary and secondary entity. The relationship of scrotal imaging to the overall clinical presentation and evaluation of these patients is emphasized in testicular torsion, torsion of the testicular appendages, epididymitis, abscess, trauma, tumor, spermatocele, and varicocele. The techniques, clinical utility, and relationship to radionuclide imaging of Doppler ultrasound and gray scale ultrasound scanning are reviewed. Doppler ultrasound results in many false negative studies in testicular torsion. Gray scale ultrasound is useful in clarifying the nature of scrotal masses.

  2. Upright CBCT: A novel imaging technique

    Directory of Open Access Journals (Sweden)

    Xenia J Fave

    2014-03-01

    Full Text Available Purpose: We present a method for acquiring and correcting upright images using the on board CBCT imager. An upright imaging technique would allow for the introduction of upright radiation therapy treatments, which would benefit a variety of patients including those with thoracic cancers whose lung volumes are increased in an upright position and those who experience substantial discomfort during supine treatment positions.Methods: To acquire upright CBCT images, the linac head was positioned at 0 degrees, the KV imager and detector arms extended to their lateral positions, and the couch placed at 270 degrees. The KV imager was programmed to begin taking continuous fluoroscopic projections as the couch rotated from 270 to 90 degrees. The FOV was extended by performing this procedure twice, once with the detector shifted 14.5 cm towards the gantry and once with it shifted 14.5 cm away from the gantry. The two resulting sets of images were stitched together prior to reconstruction. The imaging parameters were chosen to deliver the some dose as that delivered during a simulation CT. A simulation CT was deformably registered to an upright CBCT reconstruction in order to evaluate the possibility of correcting the HU values via mapping.Results: Both spatial linearity and high contrast resolution were maintained in upright CBCT when compared to a simulation CT. Low contrast resolution and HU linearity decreased. Streaking artifacts were caused by the limited 180 degree arc angle and a sharp point artifact in the center of the axial slices resulted at the site of the stitching. A method for correcting the HUs was shown to be robust against these artifacts.Conclusion: Upright CBCT could be of great benefit to many patients. This study demonstrates its feasibility and presents solutions to some of its first hurdles before clinical implementation.--------------------------Cite this article as:Fave X, Yang J, Balter P, Court L. Upright CBCT: A novel imaging

  3. Infrared Imaging Data Reduction Software and Techniques

    CERN Document Server

    Sabbey, C N; Lewis, J R; Irwin, M J; Sabbey, Chris N.; Mahon, Richard G. Mc; Lewis, James R.; Irwin, Mike J.

    2001-01-01

    We describe the InfraRed Data Reduction (IRDR) software package, a small ANSI C library of fast image processing routines for automated pipeline reduction of infrared (dithered) observations. We developed the software to satisfy certain design requirements not met in existing packages (e.g., full weight map handling) and to optimize the software for large data sets (non-interactive tasks that are CPU and disk efficient). The software includes stand-alone C programs for tasks such as running sky frame subtraction with object masking, image registration and coaddition with weight maps, dither offset measurement using cross-correlation, and object mask dilation. Although we currently use the software to process data taken with CIRSI (a near-IR mosaic imager), the software is modular and concise and should be easy to adapt/reuse for other work. IRDR is available from anonymous ftp to ftp.ast.cam.ac.uk in pub/sabbey.

  4. Special feature on imaging systems and techniques

    Science.gov (United States)

    Yang, Wuqiang; Giakos, George

    2013-07-01

    The IEEE International Conference on Imaging Systems and Techniques (IST'2012) was held in Manchester, UK, on 16-17 July 2012. The participants came from 26 countries or regions: Austria, Brazil, Canada, China, Denmark, France, Germany, Greece, India, Iran, Iraq, Italy, Japan, Korea, Latvia, Malaysia, Norway, Poland, Portugal, Sweden, Switzerland, Taiwan, Tunisia, UAE, UK and USA. The technical program of the conference consisted of a series of scientific and technical sessions, exploring physical principles, engineering and applications of new imaging systems and techniques, as reflected by the diversity of the submitted papers. Following a rigorous review process, a total of 123 papers were accepted, and they were organized into 30 oral presentation sessions and a poster session. In addition, six invited keynotes were arranged. The conference not only provided the participants with a unique opportunity to exchange ideas and disseminate research outcomes but also paved a way to establish global collaboration. Following the IST'2012, a total of 55 papers, which were technically extended substantially from their versions in the conference proceeding, were submitted as regular papers to this special feature of Measurement Science and Technology . Following a rigorous reviewing process, 25 papers have been finally accepted for publication in this special feature and they are organized into three categories: (1) industrial tomography, (2) imaging systems and techniques and (3) image processing. These papers not only present the latest developments in the field of imaging systems and techniques but also offer potential solutions to existing problems. We hope that this special feature provides a good reference for researchers who are active in the field and will serve as a catalyst to trigger further research. It has been our great pleasure to be the guest editors of this special feature. We would like to thank the authors for their contributions, without which it would

  5. Open partial nephrectomy: ancient art or currently available technique?

    Science.gov (United States)

    Seveso, Mauro; Grizzi, Fabio; Bozzini, Giorgio; Mandressi, Alberto; Guazzoni, Giorgio; Taverna, Gianluigi

    2015-12-01

    Renal cell carcinoma (RCC) accounts for 3 % of adult solid tumors, with the highest incidence between 50 and 70 years of age. Nephron-sparing surgery was initially reserved to patients with small renal masses detected in anatomically or functionally solitary kidney or in the presence of multiple bilateral tumors or hereditary forms of RCC, which posed a high risk of developing a tumor in the contralateral kidney. Nowadays, partial nephrectomy (PN) has grown up to an established approach for the treatment of small renal masses. In patients with T1a-staged RCCs, PN has proven to be associated with better survival, long-term renal function preservation with lower dialysis need or renal transplantation. Currently, most of the kidney masses are incidentally detected, up to 40 %, with smaller size due to the widespread use of imaging modalities such as ultrasound, computed tomography and magnetic resonance. Here we review the role of open PN in the management of small renal masses particularly focusing on indications, oncological outcomes and comparison with laparoscopic and robotic PN. Recent studies demonstrate that PN confers better survival, oncologic equivalence and lower risk of severe chronic kidney disease compared to radical nephrectomy becoming then the gold-standard surgical technique, even if increasingly challenged by laparoscopic and/or robot-assisted partial nephrectomy which in the hands of experts seems to achieve comparable outcome results albeit with slightly higher complication rate.

  6. MPPT Technique Based on Current and Temperature Measurements

    Directory of Open Access Journals (Sweden)

    Eduardo Moreira Vicente

    2015-01-01

    Full Text Available This paper presents a new maximum power point tracking (MPPT method based on the measurement of temperature and short-circuit current, in a simple and efficient approach. These measurements, which can precisely define the maximum power point (MPP, have not been used together in other existing techniques. The temperature is measured with a low cost sensor and the solar irradiance is estimated through the relationship of the measured short-circuit current and its reference. Fast tracking speed and stable steady-state operation are advantages of this technique, which presents higher performance when compared to other well-known techniques.

  7. Acute stroke magnetic resonance imaging: current status and future perspective.

    Science.gov (United States)

    Kloska, Stephan P; Wintermark, Max; Engelhorn, Tobias; Fiebach, Jochen B

    2010-03-01

    Cerebral stroke is one of the most frequent causes of permanent disability or death in the western world and a major burden in healthcare system. The major portion is caused by acute ischemia due to cerebral artery occlusion by a clot. The minority of strokes is related to intracerebral hemorrhage or other sources. To limit the permanent disability in ischemic stroke patients resulting from irreversible infarction of ischemic brain tissue, major efforts were made in the last decade. To extend the time window for thrombolysis, which is the only approved therapy, several imaging parameters in computed tomography and magnetic resonance imaging (MRI) have been investigated. However, the current guidelines neglect the fact that the portion of potentially salvageable ischemic tissue (penumbra) is not dependent on the time window but the individual collateral blood flow. Within the last years, the differentiation of infarct core and penumbra with MRI using diffusion-weighted images (DWI) and perfusion imaging (PI) with parameter maps was established. Current trials transform these technical advances to a redefined patient selection based on physiological parameters determined by MRI. This review article presents the current status of MRI for acute stroke imaging. A special focus is the ischemic stroke. In dependence on the pathophysiology of cerebral ischemia, the basic principle and diagnostic value of different MRI sequences are illustrated. MRI techniques for imaging of the main differential diagnoses of ischemic stroke are mentioned. Moreover, perspectives of MRI for imaging-based acute stroke treatment as well as monitoring of restorative stroke therapy from recent trials are discussed.

  8. Acute stroke magnetic resonance imaging: current status and future perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kloska, Stephan P. [University of Erlangen-Nuernberg, Department of Neuroradiology, Erlangen (Germany); University of Muenster, Department of Clinical Radiology, Muenster (Germany); Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, Charlottesville, VA (United States); Engelhorn, Tobias [University of Erlangen-Nuernberg, Department of Neuroradiology, Erlangen (Germany); Fiebach, Jochen B. [Charite, Universitaetsmedizin Berlin, Campus Benjamin Franklin, Center for Stroke Research Berlin (CSB), Department of Neurology, Berlin (Germany)

    2010-03-15

    Cerebral stroke is one of the most frequent causes of permanent disability or death in the western world and a major burden in healthcare system. The major portion is caused by acute ischemia due to cerebral artery occlusion by a clot. The minority of strokes is related to intracerebral hemorrhage or other sources. To limit the permanent disability in ischemic stroke patients resulting from irreversible infarction of ischemic brain tissue, major efforts were made in the last decade. To extend the time window for thrombolysis, which is the only approved therapy, several imaging parameters in computed tomography and magnetic resonance imaging (MRI) have been investigated. However, the current guidelines neglect the fact that the portion of potentially salvageable ischemic tissue (penumbra) is not dependent on the time window but the individual collateral blood flow. Within the last years, the differentiation of infarct core and penumbra with MRI using diffusion-weighted images (DWI) and perfusion imaging (PI) with parameter maps was established. Current trials transform these technical advances to a redefined patient selection based on physiological parameters determined by MRI. This review article presents the current status of MRI for acute stroke imaging. A special focus is the ischemic stroke. In dependence on the pathophysiology of cerebral ischemia, the basic principle and diagnostic value of different MRI sequences are illustrated. MRI techniques for imaging of the main differential diagnoses of ischemic stroke are mentioned. Moreover, perspectives of MRI for imaging-based acute stroke treatment as well as monitoring of restorative stroke therapy from recent trials are discussed. (orig.)

  9. Multi-technique imaging of sarcoidosis

    Energy Technology Data Exchange (ETDEWEB)

    Balan, A. [Department of Clinical Radiology, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Hoey, E.T.D. [Department of Clinical Radiology, Heartlands Hospital, Bordesley Green, Birmingham (United Kingdom); Sheerin, F. [Department of Neuroradiology, The John Radcliffe, Headington, Oxford (United Kingdom); Lakkaraju, A. [Department of Clinical Radiology, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Chowdhury, F.U., E-mail: fahmid.chowdhury@leedsth.nhs.u [Department of Clinical Radiology, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom)

    2010-09-15

    Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. The diagnosis is suggested on the basis of wide ranging clinical and radiological manifestations, and is supported by the histological demonstration of non-caseating granulomas in affected tissues. This review highlights the multisystem radiological features of the disease across a variety of imaging methods including multidetector computed tomography (CT), magnetic resonance imaging (MRI) as well as functional radionuclide techniques, particularly 2-[{sup 18}F]-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT). It is important for the radiologist to be aware of the varied radiological manifestations of sarcoidosis in order to recognize and suggest the diagnosis in the appropriate clinical setting.

  10. A New PWM Modifying Technique for Reconstructing Three-phase Currents from DC Bus Current

    Science.gov (United States)

    Aoyagi, Shigehisa; Iwaji, Yoshitaka; Tobari, Kazuaki; Sakamoto, Kiyoshi

    Vector control is used to drive a DC brushless motor and generally needs current information. DC bus current detection is often adopted as a low cost method for reconstructing three-phase currents. PWM modifying techniques increase the DC pulse duration, thereby enabling easy detection of the DC bus current. However, these techniques have two problems: reducing a noise frequency and making the reconstructed current waveforms distorted by current ripple. In the techniques, modification signals are added to the three-phase voltage commands; the sum of the signals over a single cycle is zero. The authors examined several PWM modifying techniques from the points of view of noise and current distortion performance. One of the techniques had a good noise performance, and the frequency component of the noise was the same as the carrier frequency (fc). However, the reconstructed current waveforms were distorted. The total harmonic distortion (THD) varied from 1.7% to 4.1%. Another technique had a very poor noise performance, and the frequency component on the noise was one-fourth of fc. The authors developed a new PWM modifying method called “Half Pulse Shift”, which achieves the optimum noise and current distortion performance. The frequency component of the new method was two-thirds of fc, and the current waveforms were not distorted; the THD in the simulations and experiments was 0.5%-1.4% and 3.4%-3.6%, respectively.

  11. Employing image processing techniques for cancer detection using microarray images.

    Science.gov (United States)

    Dehghan Khalilabad, Nastaran; Hassanpour, Hamid

    2017-02-01

    Microarray technology is a powerful genomic tool for simultaneously studying and analyzing the behavior of thousands of genes. The analysis of images obtained from this technology plays a critical role in the detection and treatment of diseases. The aim of the current study is to develop an automated system for analyzing data from microarray images in order to detect cancerous cases. The proposed system consists of three main phases, namely image processing, data mining, and the detection of the disease. The image processing phase performs operations such as refining image rotation, gridding (locating genes) and extracting raw data from images the data mining includes normalizing the extracted data and selecting the more effective genes. Finally, via the extracted data, cancerous cell is recognized. To evaluate the performance of the proposed system, microarray database is employed which includes Breast cancer, Myeloid Leukemia and Lymphomas from the Stanford Microarray Database. The results indicate that the proposed system is able to identify the type of cancer from the data set with an accuracy of 95.45%, 94.11%, and 100%, respectively.

  12. Novel imaging technique for birefringent materials

    CERN Document Server

    Lewis, J G

    1998-01-01

    less than 40 seconds. Retardation and orientation changes of less than 1nm and 1 deg, respectively, can be resolved with a spatial resolution close to that of a conventional polarizing microscope image. A wide variety of optically anisotropic materials have been examined to demonstrate both the quantitative and qualitative nature of this new sensitive polarization microscopy technique. Preliminary measurements have shown that when the system is extended to use two or more wavelengths it is also capable of directly extracting information about the order of the phase difference. Many transparent materials including crystals, polymers, biological tissues and textile fibres are birefringent or optically anisotropic, i.e. the refractive index varies with the direction of vibration of light. Birefringent measurements are important as they provide information about the underlying structure of a material. In general, the most sensitive techniques for measuring birefringence are those that modulate the polarization st...

  13. Recent Advances in Techniques for Hyperspectral Image Processing

    Science.gov (United States)

    Plaza, Antonio; Benediktsson, Jon Atli; Boardman, Joseph W.; Brazile, Jason; Bruzzone, Lorenzo; Camps-Valls, Gustavo; Chanussot, Jocelyn; Fauvel, Mathieu; Gamba, Paolo; Gualtieri, Anthony; Marconcini, Mattia; Tilton, James C.; Trianni, Giovanna

    2009-01-01

    Imaging spectroscopy, also known as hyperspectral imaging, has been transformed in less than 30 years from being a sparse research tool into a commodity product available to a broad user community. Currently, there is a need for standardized data processing techniques able to take into account the special properties of hyperspectral data. In this paper, we provide a seminal view on recent advances in techniques for hyperspectral image processing. Our main focus is on the design of techniques able to deal with the highdimensional nature of the data, and to integrate the spatial and spectral information. Performance of the discussed techniques is evaluated in different analysis scenarios. To satisfy time-critical constraints in specific applications, we also develop efficient parallel implementations of some of the discussed algorithms. Combined, these parts provide an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on future potentials and emerging challenges in the design of robust hyperspectral imaging algorithms

  14. Image encryption techniques based on the fractional Fourier transform

    Science.gov (United States)

    Hennelly, B. M.; Sheridan, J. T.

    2003-11-01

    The fractional Fourier transform, (FRT), is a generalisation of the Fourier transform which allows domains of mixed spatial frequency and spatial information to be examined. A number of method have recently been proposed in the literature for the encryption of two dimensional information using optical systems based on the FRT. Typically, these methods require random phase screen keys to decrypt the data, which must be stored at the receiver and must be carefully aligned with the received encrypted data. We have proposed a new technique based on a random shifting or Jigsaw transformation. This method does not require the use of phase keys. The image is encrypted by juxtaposition of sections of the image in various FRT domains. The new method has been compared numerically with existing methods and shows comparable or superior robustness to blind decryption. An optical implementation is also proposed and the sensitivity of the various encryption keys to blind decryption is quantified. We also present a second image encryption technique, which is based on a recently proposed method of optical phase retrieval using the optical FRT and one of its discrete counterparts. Numerical simulations of the new algorithm indicates that the sensitivity of the keys is much greater than any of the techniques currently available. In fact the sensitivity appears to be so high that optical implementation, based on existing optical signal processing technology, may be impossible. However, the technique has been shown to be a powerful method of 2-D image data encryption.

  15. Coronary imaging techniques with emphasis on CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lederlin, Mathieu; Latrabe, Valerie; Corneloup, Olivier; Cochet, Hubert; Montaudon, Michel; Laurent, Francois [Hopital Cardiologique, CHU Bordeaux, Thoracic and Cardiovascular Imaging Department, Pessac (France); Thambo, Jean-Benoit [Hopital Cardiologique, CHU Bordeaux, Pediatric and Adult Congenital Heart Disease Unit, Pessac (France)

    2011-12-15

    Coronary artery imaging in children is challenging, with high demands both on temporal and spatial resolution due to high heart rates and smaller anatomy. Although invasive conventional coronary angiography remains the benchmark technique, over the past 10 years, CT and MRI have emerged in the field of coronary imaging. The choice of hardware is important. For CT, the minimum requirement is a 64-channel scanner. The temporal resolution of the scanner is most important for optimising image quality and minimising radiation dose. Manufacturers have developed several modes of electrocardiographic (ECG) triggering to facilitate dose reduction. Recent technical advances have opened new possibilities in MRI coronary imaging. As a non-ionising radiation technique, MRI is of great interest in paediatric imaging. It is currently recommended in centres with appropriate expertise for the screening of patients with suspected congenital coronary anomalies. However, MRI is still not feasible in infants. This review describes and discusses the technical requirements and the pros and cons of all three techniques. (orig.)

  16. A Review of Image Mosaicing Techniques

    OpenAIRE

    Vaghela, Dushyant; Naina, Prof. Kapildev

    2014-01-01

    Image Mosaicing is a method of constructing multiple images of the same scene into a larger image. The output of the image mosaic will be the union of two input images. Image-mosaicing algorithms are used to get mosaiced image. Image Mosaicing processed is basically divided in to 5 phases. Which includes; Feature point extraction, Image registration, Homography computation, Warping and Blending if Image. Various corner detection algorithm is being used for Feature extraction. This corner prod...

  17. Emerging Techniques in Brain Tumor Imaging: What Radiologists Need to Know

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minjae; Kim, Ho Sung [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of)

    2016-11-01

    Among the currently available brain tumor imaging, advanced MR imaging techniques, such as diffusion-weighted MR imaging and perfusion MR imaging, have been used for solving diagnostic challenges associated with conventional imaging and for monitoring the brain tumor treatment response. Further development of advanced MR imaging techniques and postprocessing methods may contribute to predicting the treatment response to a specific therapeutic regimen, particularly using multi-modality and multiparametric imaging. Over the next few years, new imaging techniques, such as amide proton transfer imaging, will be studied regarding their potential use in quantitative brain tumor imaging. In this review, the pathophysiologic considerations and clinical validations of these promising techniques are discussed in the context of brain tumor characterization and treatment response.

  18. Emerging techniques in brain tumor imaging: What radiologists need to know

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Jae; Kim, Ho Sung [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2016-09-15

    Among the currently available brain tumor imaging, advanced MR imaging techniques, such as diffusion-weighted MR imaging and perfusion MR imaging, have been used for solving diagnostic challenges associated with conventional imaging and for monitoring the brain tumor treatment response. Further development of advanced MR imaging techniques and postprocessing methods may contribute to predicting the treatment response to a specific therapeutic regimen, particularly using multi-modality and multiparametric imaging. Over the next few years, new imaging techniques, such as amide proton transfer imaging, will be studied regarding their potential use in quantitative brain tumor imaging. In this review, the pathophysiologic considerations and clinical validations of these promising techniques are discussed in the context of brain tumor characterization and treatment response.

  19. Watermarking Digital Images Based on a Content Based Image Retrieval Technique

    CERN Document Server

    Tsolis, Dimitrios K; Papatheodorou, Theodore S

    2008-01-01

    The current work is focusing on the implementation of a robust watermarking algorithm for digital images, which is based on an innovative spread spectrum analysis algorithm for watermark embedding and on a content-based image retrieval technique for watermark detection. The highly robust watermark algorithms are applying "detectable watermarks" for which a detection mechanism checks if the watermark exists or no (a Boolean decision) based on a watermarking key. The problem is that the detection of a watermark in a digital image library containing thousands of images means that the watermark detection algorithm is necessary to apply all the keys to the digital images. This application is non-efficient for very large image databases. On the other hand "readable" watermarks may prove weaker but easier to detect as only the detection mechanism is required. The proposed watermarking algorithm combine's the advantages of both "detectable" and "readable" watermarks. The result is a fast and robust watermarking algor...

  20. Non-Destructive Techniques Based on Eddy Current Testing

    Science.gov (United States)

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  1. Non-Destructive Techniques Based on Eddy Current Testing

    Directory of Open Access Journals (Sweden)

    Ernesto Vázquez-Sánchez

    2011-02-01

    Full Text Available Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future.

  2. Non-destructive techniques based on eddy current testing.

    Science.gov (United States)

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future.

  3. A Review On Segmentation Based Image Compression Techniques

    Directory of Open Access Journals (Sweden)

    S.Thayammal

    2013-11-01

    Full Text Available Abstract -The storage and transmission of imagery become more challenging task in the current scenario of multimedia applications. Hence, an efficient compression scheme is highly essential for imagery, which reduces the requirement of storage medium and transmission bandwidth. Not only improvement in performance and also the compression techniques must converge quickly in order to apply them for real time applications. There are various algorithms have been done in image compression, but everyone has its own pros and cons. Here, an extensive analysis between existing methods is performed. Also, the use of existing works is highlighted, for developing the novel techniques which face the challenging task of image storage and transmission in multimedia applications.

  4. The Current Status of Peer Assessment Techniques and Sociometric Methods.

    Science.gov (United States)

    Bukowski, William M; Castellanos, Melisa; Persram, Ryan J

    2017-09-01

    Current issues in the use of peer assessment techniques and sociometric methods are discussed. Attention is paid to the contributions of the four articles in this volume. Together these contributions point to the continual level of change and progress in these techniques. They also show that the paradigm underlying these methods has been unchanged for decades. It is argued that this domain is ripe for a paradigm change that takes advantage of recent developments in statistical techniques and technology. © 2017 Wiley Periodicals, Inc.

  5. Efficient imaging techniques using an ultrasonic array

    Science.gov (United States)

    Moreau, L.; Hunter, A. J.; Drinkwater, B. W.; Wilcox, P. D.

    2010-03-01

    Over the past few years, ultrasonic phased arrays have shown good potential for non-destructive testing (NDT), thanks to high resolution imaging algorithms that allow the characterization of defects in a structure. Many algorithms are based on the full matrix capture, obtained by firing each element of an ultrasonic array independently, while collecting the data with all elements. Because of the finite sound velocity in the specimen, two consecutive firings must be separated by a minimum time interval. Therefore, more elements in the array require longer data acquisition times. Moreover, if the array has N elements, then the full matrix contains N2 temporal signals to be processed. Because of the limited calculation speed of current computers, a large matrix of data can result in rather long post-processing times. In an industrial context where real-time imaging is desirable, it is crucial to reduce acquisition and/or post-processing times. This paper investigates methods designed to reduce acquisition and post-processing times for the TFM and wavenumber algorithms. To reduce data capture and post-processing, limited transmission cycles are used. Post-processing times is also further reduced by demodulating the data to baseband, which allows reducing the sampling rate of signals. Results are presented so that a compromise can be made between acquisition time, post-processing time and image quality. Possible improvement of images quality, using the effective aperture theory, is discussed. This has been implemented for the TFM but it still has to be developed for the wavenumber algorithm.

  6. Compressed sensing imaging techniques for radio interferometry

    CERN Document Server

    Wiaux, Y; Puy, G; Scaife, A M M; Vandergheynst, P

    2009-01-01

    Radio interferometry probes astrophysical signals through incomplete and noisy Fourier measurements. The theory of compressed sensing demonstrates that such measurements may actually suffice for accurate reconstruction of sparse or compressible signals. We propose new generic imaging techniques based on convex optimization for global minimization problems defined in this context. The versatility of the framework notably allows introduction of specific prior information on the signals, which offers the possibility of significant improvements of reconstruction relative to the standard local matching pursuit algorithm CLEAN used in radio astronomy. We illustrate the potential of the approach by studying reconstruction performances on simulations of two different kinds of signals observed with very generic interferometric configurations. The first kind is an intensity field of compact astrophysical objects. The second kind is the imprint of cosmic strings in the temperature field of the cosmic microwave backgroun...

  7. High-resolution three-dimensional imaging of a depleted CMOS sensor using an edge Transient Current Technique based on the Two Photon Absorption process (TPA-eTCT)

    CERN Document Server

    García, Marcos Fernández; Echeverría, Richard Jaramillo; Moll, Michael; Santos, Raúl Montero; Moya, David; Pinto, Rogelio Palomo; Vila, Iván

    2016-01-01

    For the first time, the deep n-well (DNW) depletion space of a High Voltage CMOS sensor has been characterized using a Transient Current Technique based on the simultaneous absorption of two photons. This novel approach has allowed to resolve the DNW implant boundaries and therefore to accurately determine the real depleted volume and the effective doping concentration of the substrate. The unprecedented spatial resolution of this new method comes from the fact that measurable free carrier generation in two photon mode only occurs in a micrometric scale voxel around the focus of the beam. Real three-dimensional spatial resolution is achieved by scanning the beam focus within the sample.

  8. Current research projects on traffic conflicts technique studies.

    NARCIS (Netherlands)

    Hondel, M. van den & and Kraay, J.H.

    1979-01-01

    A review of current research concerning the development, evaluation and use of the traffic conflicts technique is presented. The 32 studies, selected from the IRRD data base, are listed alphabetically by names of countries and under countries by names of research organizations. The IRRD descriptions

  9. A Survey on Image Segmentation Techniques Used In Leukemia Detection

    Directory of Open Access Journals (Sweden)

    Mashiat Fatma

    2014-04-01

    Full Text Available Image segmentation commonly known as partitioning of an image is one of the intrinsic parts of any image processing technique. In this image processing step, the digital image of choice is segregated into sets of pixels on the basis of some predefined and preselected measures or standards. There have been presented many algorithms for segmenting a digital image. This paper presents a general review of algorithms that have been presented for the purpose of image segmentation.

  10. Reconstruction of conductivity and current density images using only one component of magnetic field measurements.

    Science.gov (United States)

    Seo, Jin Keun; Yoon, Jeong-Rock; Woo, Eung Je; Kwon, Ohin

    2003-09-01

    Magnetic resonance current density imaging (MRCDI) is to provide current density images of a subject using a magnetic resonance imaging (MRI) scanner with a current injection apparatus. The injection current generates a magnetic field that we can measure from MR phase images. We obtain internal current density images from the measured magnetic flux densities via Ampere's law. However, we must rotate the subject to acquire all of the three components of the induced magnetic flux density. This subject rotation is impractical in clinical MRI scanners when the subject is a human body. In this paper, we propose a way to eliminate the requirement of subject rotation by careful mathematical analysis of the MRCDI problem. In our new MRCDI technique, we need to measure only one component of the induced magnetic flux density and reconstruct both cross-sectional conductivity and current density images without any subject rotation.

  11. Current techniques for assessing developmental neurotoxicity of pesticides

    Institute of Scientific and Technical Information of China (English)

    Yu GAO; Ying TIAN; Xiaoming SHEN

    2008-01-01

    Organophosphates (OPs) and Pyrethroids (PRY) have been widely used in agriculture and in the home as broad spectrum insecticides, but may produce considerable risk to human health, especially to children. Children are more susceptible to environmental exposure, and concern about the neurotoxic effects of pesticide exposure on children is increasing. There is a need for better understanding of the potential developmental neu-rotoxicity of pesticides. Techniques for assessing devel-opmental neurotoxicity of pesticides will continue to be developed, rendering a need for flexibility of testing para-digms. Current techniques used in evaluating the devel-opmental neurotoxicity of OPs and PRY are presented in this review. These include: (1) In vitro techniques (PC12 cells, C6 cells and other cell models); (2) Non-mammalian models (sea urchins, zebrafish and other non-mammalian models); and (3) In vivo mammalian models (morpho-logical techniques, neurobehavioral assessments and biomarkers).

  12. Development of imaging techniques for fast neutron radiography in Japan

    CERN Document Server

    Fujine, S; Yoshii, K; Kamata, M; Tamaki, M; Ohkubo, K; Ikeda, Y; Kobayashi, H

    1999-01-01

    Neutron radiography with fast neutron beams (FNR) has been studied at the fast neutron source reactor 'YAYOI' of the University of Tokyo since 1986. Imaging techniques for FNR have been developed for CR-39 track-etch detector, electronic imaging system (television method), direct film method, imaging plate and also fast and thermal neutron concurrent imaging method. The review of FNR imaging techniques and some applications are reported in this paper.

  13. Review Article: An Overview of Image Compression Techniques

    Directory of Open Access Journals (Sweden)

    M. Marimuthu

    2012-12-01

    Full Text Available To store an image, large quantities of digital data are required. Due to limited bandwidth, image must be compressed before transmission. However, image compression reduces the image fidelity, when an image is compressed at low bitrates. Hence, the compressed images suffer from block artifacts. To meet this, several compression schemes have been developed in image processing. This study presents an overview of compression techniques for image applications. It covers the lossy and lossless compression algorithm used for still image and other applications. The focus of this article is based on the overview of VLSI DCT architecture for image compression. Further, this new approach may provide better results.

  14. Multispectral fluorescence imaging techniques for nondestructive food safety inspection

    Science.gov (United States)

    Kim, Moon S.; Lefcourt, Alan M.; Chen, Yud-Ren

    2004-03-01

    The use of spectral sensing has gained acceptance as a rapid means for nondestructive inspection of postharvest food produce. Current technologies generally use color or a single wavelength camera technology. The applicability and sensitivity of these techniques can be expanded through the use of multiple wavelengths. Reflectance in the Vis/NIR is the prevalent spectral technique. Fluorescence, compared to reflectance, is regarded as a more sensitive technique due to its dynamic responses to subtle changes in biological entities. Our laboratory has been exploring fluorescence as a potential means for detection of quality and wholesomeness of food products. Applications of fluorescence sensing require an understanding of the spectral characteristics emanating from constituents and potential contaminants. A number of factors affecting fluorescence emission characteristics are discussed. Because of relatively low fluorescence quantum yield from biological samples, a system with a powerful pulse light source such as a laser coupled with a gated detection device is used to harvest fluorescence, in the presence of ambient light. Several fluorescence sensor platforms developed in our laboratory, including hyperspectral imaging, and laser-induced fluorescence (LIF) and steady-state fluorescence imaging systems with multispectral capabilities are presented. We demonstrate the potential uses of recently developed fluorescence imaging platforms in food safety inspection of apples contaminated with animal feces.

  15. Biopsy of parotid masses:Review of current techniques

    Institute of Scientific and Technical Information of China (English)

    Sananda Haldar; Joseph D Sinnott; Kemal M Tekeli; Samuel S Turner; David C Howlett

    2016-01-01

    Definitive diagnosis of parotid gland masses is required optimal management planning and for prognosis. There is controversy over whether fine needle aspiration cytology(FNAC) or ultrasound guided core biopsy(USCB) should be the standard for obtaining a biopsy. The aim of this review is to assess the current evidence available to assess the benefits of each technique and also to assess the use of intra-operative frozen section(IOFS). Literature searches were performed using pubmed and google scholar. The literature has been reviewed and the evidence is presented. FNAC is an accepted and widely used technique. It has been shown to have variable diagnostic capabilities depending on centres and experience of staff. USCB has a highly consistent diagnostic accuracy and can help with tumour grading and staging. However, the technique is more invasive and there is a question regarding potential for seeding. Furthermore, USCB is less likely to be offered as part of a one-stop clinic. IOFS has no role as a first line diagnostic technique but may be reserved as an adjunct or for lesions not amenable to percutaneous biopsy. On balance, USCB seems to be the method of choice. The current evidence suggests it has superior diagnostic potential and is safe. With time, USCB is likely to supplant FNAC as the biopsy technique of choice, replicating that which has occurred already in other areas of medicine such a breast practice.

  16. Image Mosaic Techniques OptimizationUsing Wavelet

    Institute of Scientific and Technical Information of China (English)

    ZHOUAn-qi; CUILi

    2014-01-01

    This essay concentrates on two key procedures of image mosaic——image registration and imagefusion.Becauseof the character of geometric transformation invariance of edge points, wecalculate the angle difference of the direction vector ofedge points in different images anddraw an angle difference histogramto adjust the rotationproblem. Through this way, algorithm based on gray information is expandedandcan be used in images withdisplacementand rotation. Inthe term of image fusion, wavelet multi-scale analysis is used to fuse spliced images. In order to choose the best method of imagefusion,weevaluate the results of different methods of image fusion by cross entropy.

  17. Image Interpolation Using Kriging Technique for Spatial Data

    OpenAIRE

    Jassim, Firas Ajil; Altaany, Fawzi Hasan

    2013-01-01

    Image interpolation has been used spaciously by customary interpolation techniques. Recently, Kriging technique has been widely implemented in simulation area and geostatistics for prediction. In this article, Kriging technique was used instead of the classical interpolation methods to predict the unknown points in the digital image array. The efficiency of the proposed technique was proven using the PSNR and compared with the traditional interpolation techniques. The results showed that Krig...

  18. Defect detection in conducting materials using eddy current testing techniques

    Directory of Open Access Journals (Sweden)

    Brauer Hartmut

    2014-01-01

    Full Text Available Lorentz force eddy current testing (LET is a novel nondestructive testing technique which can be applied preferably to the identification of internal defects in nonmagnetic moving conductors. The LET is compared (similar testing conditions with the classical eddy current testing (ECT. Numerical FEM simulations have been performed to analyze the measurements as well as the identification of internal defects in nonmagnetic conductors. The results are compared with measurements to test the feasibility of defect identification. Finally, the use of LET measurements to estimate of the electrical conductors under test are described as well.

  19. Image Resolution Enhancement using DWT and Spatial Domain Interpolation Technique

    Directory of Open Access Journals (Sweden)

    Mrs. G. Padma Priya

    2016-02-01

    Full Text Available Image Resolution is one of the important quality metrics of images. Images with high resolution are required in many fields. In this paper, a new resolution enhancement technique is proposed based on the interpolation of four sub band images generated by Discrete Wavelet Transform (DWT and the original Low Resolution (LR input image. In this technique, the four sub band images generated by DWT and the input LR image are interpolated with scaling factor, α and then performed inverse DWT to obtain the intermediate High Resolution (HR Image. The difference between the intermediate HR image and the interpolated LR input image is added to the intermediate HR image to obtain final output HR Image. Lanczos interpolation is used in this technique. The proposed technique is tested on well known bench mark images. The quantitative and visual results shows the superiority of the proposed technique over the conventional and state of art image resolution enhancement techniques in wavelet domain using haar wavelet filter.

  20. Application of image fusion techniques in DSA

    Science.gov (United States)

    Ye, Feng; Wu, Jian; Cui, Zhiming; Xu, Jing

    2007-12-01

    Digital subtraction angiography (DSA) is an important technology in both medical diagnoses and interposal therapy, which can eliminate the interferential background and give prominence to blood vessels by computer processing. After contrast material is injected into an artery or vein, a physician produces fluoroscopic images. Using these digitized images, a computer subtracts the image made with contrast material from a series of post injection images made without background information. By analyzing the characteristics of DSA medical images, this paper provides a solution of image fusion which is in allusion to the application of DSA subtraction. We fuse the images of angiogram and subtraction, in order to obtain the new image which has more data information. The image that fused by wavelet transform can display the blood vessels and background information clearly, and medical experts gave high score on the effect of it.

  1. A review of imaging techniques for plant phenotyping.

    Science.gov (United States)

    Li, Lei; Zhang, Qin; Huang, Danfeng

    2014-10-24

    Given the rapid development of plant genomic technologies, a lack of access to plant phenotyping capabilities limits our ability to dissect the genetics of quantitative traits. Effective, high-throughput phenotyping platforms have recently been developed to solve this problem. In high-throughput phenotyping platforms, a variety of imaging methodologies are being used to collect data for quantitative studies of complex traits related to the growth, yield and adaptation to biotic or abiotic stress (disease, insects, drought and salinity). These imaging techniques include visible imaging (machine vision), imaging spectroscopy (multispectral and hyperspectral remote sensing), thermal infrared imaging, fluorescence imaging, 3D imaging and tomographic imaging (MRT, PET and CT). This paper presents a brief review on these imaging techniques and their applications in plant phenotyping. The features used to apply these imaging techniques to plant phenotyping are described and discussed in this review.

  2. Power electronic converters PWM strategies and current control techniques

    CERN Document Server

    Monmasson, Eric

    2013-01-01

    A voltage converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply. This title is devoted to the control of static converters, which deals with pulse-width modulation (PWM) techniques, and also discusses methods for current control. Various application cases are treated. The book is ideal for professionals in power engineering, power electronics, and electric drives industries, as well as practicing engineers, university professors, postdoctoral fellows, and graduate students.

  3. Spray drying technique: II. Current applications in pharmaceutical technology.

    Science.gov (United States)

    Sollohub, Krzysztof; Cal, Krzysztof

    2010-02-01

    This review presents current applications of spray drying in pharmaceutical technology. The topics discussed include the obtention of excipients and cospray dried composites, methods for increasing the aqueous solubility and bioavailability of active substances, and modified release profiles from spray-dried particles. This review also describes the use of the spray drying technique in the context of biological therapies, such as the spray drying of proteins, inhalable powders, and viable organisms, and the modification of the physical properties of dry plant extracts.

  4. Nondestructive examination of PHWR pressure tube using eddy current technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Jong; Choi, Sung Nam; Cho, Chan Hee; Yoo, Hyun Joo; Moon, Gyoon Young [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2014-06-15

    A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter x 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the D2O heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

  5. Current situation of endoscopic biliary cannulation and salvage techniques for difficult cases: Current strategies in Japan.

    Science.gov (United States)

    Yasuda, Ichiro; Isayama, Hiroyuki; Bhatia, Vikram

    2016-04-01

    In the pancreatobiliary session at Endoscopic Forum Japan (EFJ) 2015, current trends of routine biliary cannulation techniques and salvage techniques for difficult biliary cannulation cases were discussed. Endoscopists from nine Japanese high-volume centers along with two overseas centers participated in the questionnaires and discussion. It was concluded that, currently, in Western countries, the wire-guided cannulation (WGC) technique is favored during initial cannulation attempts. However, the conventional technique using an endoscopic retrograde cholangiopancreatography catheter with contrast medium injection is still used as first choice at most Japanese high-volume centers. The WGC technique is used as the second choice at some institutions only. After failed biliary cannulation attempts, the initial salvage option preferred in most centers includes pancreatic guidewire placement, followed by precut techniques as the second salvage choice. Among several precut techniques, the free-hand needle knife sphincterotomy with cutting upwards from the pancreatic duct is most popular. Endoscopic ultrasonography-guided rendezvous technique is also carried out as a final salvage option at select institutions.

  6. [Current operative techniques and strategies in endocrine surgery].

    Science.gov (United States)

    Gürtler, Thomas; Weber, Markus

    2011-06-01

    Technical advances and focusing on subsets modified endocrine surgery in the last ten years tremendously. There is on one side a clear trend towards minimal invasive approaches, first of all in the surgery of the adrenal glands, where the transperitoneal or retroperitoneal laparoscopic adrenalectomy has become the gold standard for tumors up to a size of 10 cm in diameter. But also in pancreatic endocrine surgery for small tumors localized in the pancreas tail and up to a certain extend in thyroid and parathyroid surgery, laparoscopic or video assisted techniques are used. On the other side more precise techniques allow a more complete and radical removal of endocrine tissue, especially in thyroid surgery. This article presents a summary of current operative techniques and strategies in endocrine surgery.

  7. Gynecologic imaging: Current and emerging applications

    Directory of Open Access Journals (Sweden)

    Iyer V

    2010-01-01

    Full Text Available Common diagnostic challenges in gynecology and the role of imaging in their evaluation are reviewed. Etiologies of abnormal uterine bleeding identified on pelvic sonography and sonohysterography are presented. An algorithmic approach for characterizing an incidentally detected adnexal mass and use of magnetic resonance imaging for definitive diagnosis are discussed. Finally, the role of F18-fluorodeoxyglucose positron emission tomography in the management of gynecological malignancies, and pitfalls associated with their use are examined.

  8. Current and future trends in imaging informatics for oncology.

    Science.gov (United States)

    Levy, Mia A; Rubin, Daniel L

    2011-01-01

    Clinical imaging plays an essential role in cancer care and research for diagnosis, prognosis, and treatment response assessment. Major advances in imaging informatics to support medical imaging have been made during the last several decades. More recent informatics advances focus on the special needs of oncologic imaging, yet gaps still remain. We review the current state, limitations, and future trends in imaging informatics for oncology care including clinical and clinical research systems. We review information systems to support cancer clinical workflows including oncologist ordering of radiology studies, radiologist review and reporting of image findings, and oncologist review and integration of imaging information for clinical decision making. We discuss informatics approaches to oncologic imaging including, but not limited to, controlled terminologies, image annotation, and image-processing algorithms. With the ongoing development of novel imaging modalities and imaging biomarkers, we expect these systems will continue to evolve and mature.

  9. A resonant series counterpulse technique for high current opening switches

    Energy Technology Data Exchange (ETDEWEB)

    Dijk, E. van [Delft Univ. of Technology (Netherlands). Lab. for Power Electronics and Electrical Machines; Gelder, P. van [TNO PML-Pulse Physics Lab., Delft (Netherlands)

    1995-01-01

    A counterpulse technique for the controlled interruption of very high currents in inductive storage pulsed power systems is described and analyzed, and some simulation results of its performance are presented. The accompanying circuit comprises a pre-charged capacitor bank, connected in series with the inductive load, which has to be provided with a current pulse. Upon actuation, a resonant counterpulse current is created in the opening switch, connected in parallel with the current source and the load. In this way, the opening switch is opened at low current. A separate closing switch prevents closing of the opening switch at high voltage. Operation of the opening switch, often a mechanical switch, at low current and low voltage prevents arc erosion of the contacts. The advantage of this circuit compared to other counterpulse circuits is that the capacitor bank does not experience a voltage reversal. Electrolytic capacitors, which have a high energy density, are applied. The remaining energy of the capacitor bank after opening the opening switch, is transferred to the load. The required initial voltage of the capacitor bank is only a few hundred volts, whereas it may be above a kilovolt in other circuits. Another advantage of the method described here is that the load does not experience a pre-current, causing unwanted preheating of the load, before the resonant current is activated. At the moment, work is being performed at the Pulse Physics Laboratory to develop the resonant series counterpulse circuit for use with rail accelerators, which must be supplied with current pulses in the millisecond range up to the mega-ampere level.

  10. Update of choroidal imaging techniques: Past, present and future.

    Science.gov (United States)

    Ruiz-Medrano, J; Flores-Moreno, I; Gutierrez-Bonet, R; Chhablani, J; Ruiz-Moreno, J M

    2017-03-01

    The choroid is the middle layer of the eye, a very vascular and pigmented tissue, with its role in several ophthalmological pathologies already having been clearly established. But it was not until the last few years that we have been able to reliably and precisely measure and quantify its shape and thickness. Ultrasound technology and indocyanine green angiography were the first techniques used for the study of the choroid, and they still maintain their use and clinical indications for the diagnosis and management of several pathologies. But it was the advent of optical coherence tomography that was the greatest breakthrough in choroidal imaging. In this chapter, the past, current and future image modalities for the study of the choroid will be discussed, with special focus on optical coherence tomography and its latest developments. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Fingerprint Image Enhancement By Develop Mehtre Technique

    Directory of Open Access Journals (Sweden)

    Mustafa Salah Khalefa

    2011-12-01

    Full Text Available Fingerprint identification is one of the most reliable biometrics technologies. There are manyapplications of fingerprint recognition such as voting, ecommerce, bank, virtual banks and military.Fingerprint image enhancement is an essential preprocessing step in extract minutiae from the inputfingerprint images. In this paper, we propose an image enhancement method by developing Mehtermethod for directional image. The enhancement is done by added the Block Filtering, HistogramEqualization and High-Pass Filtering. We have evaluated the performance of the enhancement imagemethod by tested it with 100 fingerprint images. Experimental results show the enhancement methodimproves the recognition more accuracy.

  12. Imaging fault zones using 3D seismic image processing techniques

    Science.gov (United States)

    Iacopini, David; Butler, Rob; Purves, Steve

    2013-04-01

    Significant advances in structural analysis of deep water structure, salt tectonic and extensional rift basin come from the descriptions of fault system geometries imaged in 3D seismic data. However, even where seismic data are excellent, in most cases the trajectory of thrust faults is highly conjectural and still significant uncertainty exists as to the patterns of deformation that develop between the main faults segments, and even of the fault architectures themselves. Moreover structural interpretations that conventionally define faults by breaks and apparent offsets of seismic reflectors are commonly conditioned by a narrow range of theoretical models of fault behavior. For example, almost all interpretations of thrust geometries on seismic data rely on theoretical "end-member" behaviors where concepts as strain localization or multilayer mechanics are simply avoided. Yet analogue outcrop studies confirm that such descriptions are commonly unsatisfactory and incomplete. In order to fill these gaps and improve the 3D visualization of deformation in the subsurface, seismic attribute methods are developed here in conjunction with conventional mapping of reflector amplitudes (Marfurt & Chopra, 2007)). These signal processing techniques recently developed and applied especially by the oil industry use variations in the amplitude and phase of the seismic wavelet. These seismic attributes improve the signal interpretation and are calculated and applied to the entire 3D seismic dataset. In this contribution we will show 3D seismic examples of fault structures from gravity-driven deep-water thrust structures and extensional basin systems to indicate how 3D seismic image processing methods can not only build better the geometrical interpretations of the faults but also begin to map both strain and damage through amplitude/phase properties of the seismic signal. This is done by quantifying and delineating the short-range anomalies on the intensity of reflector amplitudes

  13. Lower-Dark-Current, Higher-Blue-Response CMOS Imagers

    Science.gov (United States)

    Pain, Bedabrata; Cunningham, Thomas; Hancock, Bruce

    2008-01-01

    Several improved designs for complementary metal oxide/semiconductor (CMOS) integrated-circuit image detectors have been developed, primarily to reduce dark currents (leakage currents) and secondarily to increase responses to blue light and increase signal-handling capacities, relative to those of prior CMOS imagers. The main conclusion that can be drawn from a study of the causes of dark currents in prior CMOS imagers is that dark currents could be reduced by relocating p/n junctions away from Si/SiO2 interfaces. In addition to reflecting this conclusion, the improved designs include several other features to counteract dark-current mechanisms and enhance performance.

  14. Interpolation Technique in Computed Tomography Image Visualisation(Short Communication

    Directory of Open Access Journals (Sweden)

    Asha Tripathi

    2002-07-01

    Full Text Available An interpolation technique has been developed for generation of enlarged dataset from a limited one-dimesional acquired dataset for improving the image quality in quick-scan tomography. The effectiveness of the technique has been tested using data acquired from the first-generation. The CT images generated using this technique have been compared with the CT images generated from the acquired dataset for the same number of projections. The image quality has been improved on account of (i enhancement of features, (ii reduction in reconstruction artifacts, and (iii magnification of the image without pixelisation.

  15. In Vivo Imaging Techniques: A New Era for Histochemical Analysis

    Science.gov (United States)

    Busato, A.; Feruglio, P. Fumene; Parnigotto, P.P.; Marzola, P.; Sbarbati, A.

    2016-01-01

    In vivo imaging techniques can be integrated with classical histochemistry to create an actual histochemistry of water. In particular, Magnetic Resonance Imaging (MRI), an imaging technique primarily used as diagnostic tool in clinical/preclinical research, has excellent anatomical resolution, unlimited penetration depth and intrinsic soft tissue contrast. Thanks to the technological development, MRI is not only capable to provide morphological information but also and more interestingly functional, biophysical and molecular. In this paper we describe the main features of several advanced imaging techniques, such as MRI microscopy, Magnetic Resonance Spectroscopy, functional MRI, Diffusion Tensor Imaging and MRI with contrast agent as a useful support to classical histochemistry. PMID:28076937

  16. Study of Associated α Particle Imaging Technique for Explosives Detection

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The explosive detecting technique about neutron mainly include the thermal neutron analysis (TNA), the fast neutron analysis (FNA), the pulse fast and thermal neutron analysis (PFTNA) and the associated α particle imaging technique about fast neutron (API).

  17. Application of digital image processing techniques to astronomical imagery 1977

    Science.gov (United States)

    Lorre, J. J.; Lynn, D. J.

    1978-01-01

    Nine specific techniques of combination of techniques developed for applying digital image processing technology to existing astronomical imagery are described. Photoproducts are included to illustrate the results of each of these investigations.

  18. Preprocessing Techniques for Image Mining on Biopsy Images

    Directory of Open Access Journals (Sweden)

    Ms. Nikita Ramrakhiani

    2015-08-01

    Full Text Available Biomedical imaging has been undergoing rapid technological advancements over the last several decades and has seen the development of many new applications. A single Image can give all the details about an organ from the cellular level to the whole-organ level. Biomedical imaging is becoming increasingly important as an approach to synthesize, extract and translate useful information from large multidimensional databases accumulated in research frontiers such as functional genomics, proteomics, and functional imaging. To fulfill this approach Image Mining can be used. Image Mining will bridge this gap to extract and translate semantically meaningful information from biomedical images and apply it for testing and detecting any anomaly in the target organ. The essential component in image mining is identifying similar objects in different images and finding correlations in them. Integration of Image Mining and Biomedical field can result in many real world applications

  19. Bayesian technique for image classifying registration.

    Science.gov (United States)

    Hachama, Mohamed; Desolneux, Agnès; Richard, Frédéric J P

    2012-09-01

    In this paper, we address a complex image registration issue arising while the dependencies between intensities of images to be registered are not spatially homogeneous. Such a situation is frequently encountered in medical imaging when a pathology present in one of the images modifies locally intensity dependencies observed on normal tissues. Usual image registration models, which are based on a single global intensity similarity criterion, fail to register such images, as they are blind to local deviations of intensity dependencies. Such a limitation is also encountered in contrast-enhanced images where there exist multiple pixel classes having different properties of contrast agent absorption. In this paper, we propose a new model in which the similarity criterion is adapted locally to images by classification of image intensity dependencies. Defined in a Bayesian framework, the similarity criterion is a mixture of probability distributions describing dependencies on two classes. The model also includes a class map which locates pixels of the two classes and weighs the two mixture components. The registration problem is formulated both as an energy minimization problem and as a maximum a posteriori estimation problem. It is solved using a gradient descent algorithm. In the problem formulation and resolution, the image deformation and the class map are estimated simultaneously, leading to an original combination of registration and classification that we call image classifying registration. Whenever sufficient information about class location is available in applications, the registration can also be performed on its own by fixing a given class map. Finally, we illustrate the interest of our model on two real applications from medical imaging: template-based segmentation of contrast-enhanced images and lesion detection in mammograms. We also conduct an evaluation of our model on simulated medical data and show its ability to take into account spatial variations

  20. Current concepts in imaging of tendinopathy

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Robert S.D.; Grainger, Andrew J

    2001-04-01

    With the rising popularity of recreational sports, radiologists are being asked to image tendons with increasing frequency. Recognition of the critical link tendons provide between muscle and bone has also led to a better understanding of the processes leading to tendon damage. While plain radiography and CT have only a limited role to play in the diagnosis of tendon abnormality, the improvements in ultrasound and MRI technology mean that tendons can now be demonstrated in exquisite detail and previously undetectable abnormalities are readily demonstrated. This article reviews the structure and pathological processes affecting tendons and discusses the role of imaging in their assessment with an emphasis on ultrasound and MRI. Campbell, R.S.D. and Grainger, A.J. (2001)

  1. COMPARATIVE ANALYSIS OF SATELLITE IMAGE PRE-PROCESSING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    T. Sree Sharmila

    2013-01-01

    Full Text Available Satellite images are corrupted by noise in its acquisition and transmission. The removal of noise from the image by attenuating the high frequency image components, removes some important details as well. In order to retain the useful information and improve the visual appearance, an effective denoising and resolution enhancement techniques are required. In this research, Hybrid Directional Lifting (HDL technique is proposed to retain the important details of the image and improve the visual appearance. The Discrete Wavelet Transform (DWT based interpolation technique is developed for enhancing the resolution of the denoised image. The performance of the proposed techniques are tested by Land Remote-Sensing Satellite (LANDSAT images, using the quantitative performance measure, Peak Signal to Noise Ratio (PSNR and computation time to show the significance of the proposed techniques. The PSNR of the HDL technique increases 1.02 dB compared to the standard denoising technique and the DWT based interpolation technique increases 3.94 dB. From the experimental results it reveals that newly developed image denoising and resolution enhancement techniques improve the image visual quality with rich textures.

  2. A Survey Paper on Fuzzy Image Segmentation Techniques

    Directory of Open Access Journals (Sweden)

    Ms. R. Saranya Pon Selvi

    2014-03-01

    Full Text Available The image segmentation plays an important role in the day-to-day life. The new technologies are emerging in the field of Image processing, especially in the domain of segmentation.Segmentation is considered as one of the main steps in image processing. It divides a digital image into multiple regions in order to analyze them. It is also used to distinguish different objects in the image. Several image segmentation techniques have been developed by the researchers in order to make images smooth and easy to evaluate. This paper presents a brief outline on some of the most commonly used segmentation techniques like thresholding, Region based, Model based, Edge detection..etc. mentioning its advantages as well as the drawbacks. Some of the techniques are suitable for noisy images.

  3. Comparative Analysis of Various Image Fusion Techniques For Biomedical Images: A Review

    Directory of Open Access Journals (Sweden)

    Nayera Nahvi,

    2014-05-01

    Full Text Available Image Fusion is a process of combining the relevant information from a set of images, into a single image, wherein the resultant fused image will be more informative and complete than any of the input images. This paper discusses implementation of DWT technique on different images to make a fused image having more information content. As DWT is the latest technique for image fusion as compared to simple image fusion and pyramid based image fusion, so we are going to implement DWT as the image fusion technique in our paper. Other methods such as Principal Component Analysis (PCA based fusion, Intensity hue Saturation (IHS Transform based fusion and high pass filtering methods are also discussed. A new algorithm is proposed using Discrete Wavelet transform and different fusion techniques including pixel averaging, min-max and max-min methods for medical image fusion. KEYWORDS:

  4. Role of imaging in testicular cancer: current and future practice.

    Science.gov (United States)

    Barrisford, Glen W; Kreydin, Evgeniy I; Preston, Mark A; Rodriguez, Dayron; Harisighani, Mukesh G; Feldman, Adam S

    2015-09-01

    The article provides a summary of the epidemiologic and clinical aspects of testicular malignancy. Current standard imaging and novel techniques are reviewed. Present data and clinical treatment trends have favored surveillance protocols over adjuvant radiation or chemotherapy for low-stage testicular malignancy. This has resulted in increasing numbers of imaging studies and the potential for increased long-term exposure risks. Understanding imaging associated risks as well as strategies to minimize these risks is of increasing importance. The development, validation and incorporation of alternative lower risk highly efficacious and cost-effective imaging techniques is essential.

  5. Current status of PET imaging in Huntington's disease.

    Science.gov (United States)

    Pagano, Gennaro; Niccolini, Flavia; Politis, Marios

    2016-06-01

    To review the developments of recent decades and the current status of PET molecular imaging in Huntington's disease (HD). A systematic review of PET studies in HD was performed. The MEDLINE, Web of Science, Cochrane and Scopus databases were searched for articles in all languages published up to 19 August 2015 using the major medical subject heading "Huntington Disease" combined with text and key words "Huntington Disease", "Neuroimaging" and "PET". Only peer-reviewed, primary research studies in HD patients and premanifest HD carriers, and studies in which clinical features were described in association with PET neuroimaging results, were included in this review. Reviews, case reports and nonhuman studies were excluded. A total of 54 PET studies were identified and analysed in this review. Brain metabolism ([(18)F]FDG and [(15)O]H2O), presynaptic ([(18)F]fluorodopa, [(11)C]β-CIT and [(11)C]DTBZ) and postsynaptic ([(11)C]SCH22390, [(11)C]FLB457 and [(11)C]raclopride) dopaminergic function, phosphodiesterases ([(18)F]JNJ42259152, [(18)F]MNI-659 and [(11)C]IMA107), and adenosine ([(18)F]CPFPX), cannabinoid ([(18)F]MK-9470), opioid ([(11)C]diprenorphine) and GABA ([(11)C]flumazenil) receptors were evaluated as potential biomarkers for monitoring disease progression and for assessing the development and efficacy of novel disease-modifying drugs in premanifest HD carriers and HD patients. PET studies evaluating brain restoration and neuroprotection were also identified and described in detail. Brain metabolism, postsynaptic dopaminergic function and phosphodiesterase 10A levels were proven to be powerful in assessing disease progression. However, no single technique may be currently considered an optimal biomarker and an integrative multimodal imaging approach combining different techniques should be developed for monitoring potential neuroprotective and preventive treatment in HD.

  6. ARRAY PULSED EDDY CURRENT IMAGING SYSTEM USED TO DETECT CORROSION

    Institute of Scientific and Technical Information of China (English)

    Yang Binfeng; Luo Feilu; Cao Xiongheng; Xu Xiaojie

    2005-01-01

    A theory model is established to describe the voltage-current response function. The peak amplitude and the zero-crossing time of the transient signal is extracted as the imaging features, array pulsed eddy current (PEC) imaging is proposed to detect corrosion. The test results show that this system has the advantage of fast scanning speed, different imaging mode and quantitative detection, it has a broad application in the aviation nondestructive testing.

  7. Terahertz Imaging Systems With Aperture Synthesis Techniques

    DEFF Research Database (Denmark)

    Krozer, Viktor; Löffler, Torsten; Dall, Jørgen

    2010-01-01

    This paper presents the research and development of two terahertz imaging systems based on photonic and electronic principles, respectively. As part of this study, a survey of ongoing research in the field of terahertz imaging is provided focusing on security applications. Existing terahertz...

  8. A Novel Technique to Image Annotation using Neural Network

    Directory of Open Access Journals (Sweden)

    Pankaj Savita

    2013-03-01

    Full Text Available : Automatic annotation of digital pictures is a key technology for managing and retrieving images from large image collection. Traditional image semantics extraction and representation schemes were commonly divided into two categories, namely visual features and text annotations. However, visual feature scheme are difficult to extract and are often semantically inconsistent. On the other hand, the image semantics can be well represented by text annotations. It is also easier to retrieve images according to their annotations. Traditional image annotation techniques are time-consuming and requiring lots of human effort. In this paper we propose Neural Network based a novel approach to the problem of image annotation. These approaches are applied to the Image data set. Our main work is focused on the image annotation by using multilayer perceptron, which exhibits a clear-cut idea on application of multilayer perceptron with special features. MLP Algorithm helps us to discover the concealed relations between image data and annotation data, and annotate image according to such relations. By using this algorithm we can save more memory space, and in case of web applications, transferring of images and download should be fast. This paper reviews 50 image annotation systems using supervised machine learning Techniques to annotate images for image retrieval. Results obtained show that the multi layer perceptron Neural Network classifier outperforms conventional DST Technique.

  9. Automated image analysis techniques for cardiovascular magnetic resonance imaging

    NARCIS (Netherlands)

    Geest, Robertus Jacobus van der

    2011-01-01

    The introductory chapter provides an overview of various aspects related to quantitative analysis of cardiovascular MR (CMR) imaging studies. Subsequently, the thesis describes several automated methods for quantitative assessment of left ventricular function from CMR imaging studies. Several novel

  10. High-accuracy current sensing circuit with current compensation technique for buck-boost converter

    Science.gov (United States)

    Rao, Yuan; Deng, Wan-Ling; Huang, Jun-Kai

    2015-03-01

    A novel on-chip current sensing circuit with current compensation technique suitable for buck-boost converter is presented in this article. The proposed technique can sense the full-range inductor current with high accuracy and high speed. It is mainly based on matched current mirror and does not require a large proportion of aspect ratio between the powerFET and the senseFET, thus it reduces the complexity of circuit design and the layout mismatch issue without decreasing the power efficiency. The circuit is fabricated with TSMC 0.25 µm 2P5M mixed-signal process. Simulation results show that the buck-boost converter can be operated at 200 kHz to 4 MHz switching frequency with an input voltage from 2.8 to 4.7 V. The output voltage is 3.6 V, and the maximum accuracy for both high and low side sensing current reaches 99% within the load current ranging from 200 to 600 mA.

  11. Color Image Classification and Retrieval using Image mining Techniques

    OpenAIRE

    Dr.V.Mohan,; Kannan, A.

    2010-01-01

    Mining Image data is one of the essential features in the present scenario. Image data is the major one which plays vital role in every aspect of the systems like business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-BasedImage Retrieval (CBIR). CBIR systems perform retrieval based on the similarity defined in terms of extracted features with more objectiveness. But, the features of t...

  12. Image Fusion Techniques for Multispectral Palm Image Enhancement

    OpenAIRE

    Rajashree Bhokare; Deepali Sale; Dr. (Mrs. ) M. A. Joshi; Dr. M. S. Gaikwad

    2013-01-01

    We proposed the multispectral image enhancement through image fusion by combining the data from the multiple spectrum to address the problem of accuracy and make the system robust against spoofing and to improve the accuracy of recognition, using more discriminating of palm images. Palm line features are clearer in the blue and green bands while red band can reveal some palm vein structure. The NIR band can show the palm vein structure as well as partial line information. Image fusion improve...

  13. Bladder exstrophy: current management and postoperative imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pierre, Ketsia [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Borer, Joseph [Boston Children' s Hospital, Department of Urology, Boston, MA (United States); Phelps, Andrew [University of California, San Francisco, Department of Pediatric Radiology, San Francisco, CA (United States); Chow, Jeanne S. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Boston Children' s Hospital, Department of Urology, Boston, MA (United States)

    2014-07-15

    Bladder exstrophy is a rare malformation characterized by an infra-umbilical abdominal wall defect, incomplete closure of the bladder with mucosa continuous with the abdominal wall, epispadias, and alterations in the pelvic bones and muscles. It is part of the exstrophy-epispadias complex, with cloacal exstrophy on the severe and epispadias on the mild ends of the spectrum. Bladder exstrophy is the most common of these entities and is more common in boys. The goal of this paper is to describe common methods of repair and to provide an imaging review of the postoperative appearances. (orig.)

  14. Techniques and applications of endoscopic spine surgery. Part I:overview of current techniques

    Institute of Scientific and Technical Information of China (English)

    Kai-Xuan Liu; MD; PhD

    2013-01-01

    Background Spinal pain is a serious health and social-economic problem. Endoscopic spine surgery as a treatment option for spinal pain has gained tremendous attention and growth in the past 2 decades, and a variety of endoscopic techniques have been invented to treat a wide range of spinal conditions. Purposes The purposes of this 2-part review article are to 1 ) overview the published techniques of endoscopic spine surgery, 2 ) summarize the applications of these techniques in treating various spinal conditions, and 3 ) evaluate the clinical evidence of the safety and effectiveness of these endoscopic techniques in treating some of the most common spinal conditions. The first part of the review article provides an overview of currently most commonly used techniques. Methods We searched the PubMed database for publications concerning endoscopic spine surgery and reviewed the relevant articles published in the English language. Results Discectomy and foraminotomy are the most common types of spine surgery that can currently be done endoscopically. Endoscopic techniques have been used to treat a wide range of spinal disorders located in the lumbar, cervical, as well as the thoracic regions of the spine.

  15. Image Information Retrieval: An Overview of Current Research

    Directory of Open Access Journals (Sweden)

    Abby A. Goodrum

    2000-01-01

    Full Text Available This paper provides an overview of current research in image information retrieval and provides an outline of areas for future research. The approach is broad and interdisciplinary and focuses on three aspects of image research (IR: text-based retrieval, content-based retrieval, and user interactions with image information retrieval systems. The review concludes with a call for image retrieval evaluation studies similar to TREC.

  16. Image Information Retrieval: An Overview of Current Research

    OpenAIRE

    Abby A. Goodrum

    2000-01-01

    This paper provides an overview of current research in image information retrieval and provides an outline of areas for future research. The approach is broad and interdisciplinary and focuses on three aspects of image research (IR): text-based retrieval, content-based retrieval, and user interactions with image information retrieval systems. The review concludes with a call for image retrieval evaluation studies similar to TREC.

  17. Current techniques for visualizing RNA in cells [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Lilith V.J.C. Mannack

    2016-04-01

    Full Text Available Labeling RNA is of utmost interest, particularly in living cells, and thus RNA imaging is an emerging field. There are numerous methods relying on different concepts ranging from hybridization-based probes, over RNA-binding proteins to chemo-enzymatic modification of RNA. These methods have different benefits and limitations. This review aims to outline the current state-of-the-art techniques and point out their benefits and limitations.

  18. Cardiac activation mapping using ultrasound current source density imaging (UCSDI).

    Science.gov (United States)

    Olafsson, Ragnar; Witte, Russell S; Jia, Congxian; Huang, Sheng-Wen; Kim, Kang; O'Donnell, Matthew

    2009-03-01

    We describe the first mapping of biological current in a live heart using ultrasound current source density imaging (UCSDI). Ablation procedures that treat severe heart arrhythmias require detailed maps of the cardiac activation wave. The conventional procedure is time-consuming and limited by its poor spatial resolution (5-10 mm). UCSDI can potentially improve on existing mapping procedures. It is based on a pressure-induced change in resistivity known as the acousto-electric (AE) effect, which is spatially confined to the ultrasound focus. Data from 2 experiments are presented. A 540 kHz ultrasonic transducer (f/# = 1, focal length = 90 mm, pulse repetition frequency = 1600 Hz) was scanned over an isolated rabbit heart perfused with an excitation-contraction decoupler to reduce motion significantly while retaining electric function. Tungsten electrodes inserted in the left ventricle recorded simultaneously the AE signal and the low-frequency electrocardiogram (ECG). UCSDI displayed spatial and temporal patterns consistent with the spreading activation wave. The propagation velocity estimated from UCSDI was 0.25 +/- 0.05 mm/ms, comparable to the values obtained with the ECG signals. The maximum AE signal-to-noise ratio after filtering was 18 dB, with an equivalent detection threshold of 0.1 mA/ cm(2). This study demonstrates that UCSDI is a potentially powerful technique for mapping current flow and biopotentials in the heart.

  19. Fingerprint image enhancement using CNN filtering techniques.

    Science.gov (United States)

    Saatci, Ertugrul; Tavsanoglu, Vedat

    2003-12-01

    Due to noisy acquisition devices and variation in impression conditions, the ridgelines of fingerprint images are mostly corrupted by various kinds of noise causing cracks, scratches and bridges in the ridges as well as blurs. These cause matching errors in fingerprint recognition. For an effective recognition the correct ridge pattern is essential which requires the enhancement of fingerprint images. Segment by segment analysis of the fingerprint pattern yields various ridge direction and frequencies. By selecting a directional filter with correct filter parameters to match ridge features at each point, we can effectively enhance fingerprint ridges. This paper proposes a fingerprint image enhancement based on CNN Gabor-Type filters.

  20. A New Image Steganography Based On First Component Alteration Technique

    Directory of Open Access Journals (Sweden)

    Amanpreet Kaur

    2009-12-01

    Full Text Available In this paper, A new image steganography scheme is proposed which is a kind of spatial domain technique. In order to hide secret data in cover-image, the first component alteration technique is used. Techniques used so far focuses only on the two or four bits of a pixel in a image (at the most five bits at the edge of an image which results in less peak to signal noise ratio and high root mean square error. In this technique, 8 bits of blue components of pixels are replaced with secret data bits. Proposed scheme can embed more data than previous schemes and shows better image quality. To prove this scheme, several experiments are performed, and are compared the experimental results with the related previous works.Keywords—image; mean square error; Peak signal to noise ratio; steganography;

  1. Digital image processing techniques in archaeology

    Digital Repository Service at National Institute of Oceanography (India)

    Santanam, K.; Vaithiyanathan, R.; Tripati, S.

    and digitized aerial photographs. However, it was not until the launch of Landsat - 1 in 1972 that digital image data became widely available for land remote sensing applications. Today with the availability of efficient computer hardware and software...

  2. Techniques in Iterative Proton CT Image Reconstruction

    CERN Document Server

    Penfold, Scott

    2015-01-01

    This is a review paper on some of the physics, modeling, and iterative algorithms in proton computed tomography (pCT) image reconstruction. The primary challenge in pCT image reconstruction lies in the degraded spatial resolution resulting from multiple Coulomb scattering within the imaged object. Analytical models such as the most likely path (MLP) have been proposed to predict the scattered trajectory from measurements of individual proton location and direction before and after the object. Iterative algorithms provide a flexible tool with which to incorporate these models into image reconstruction. The modeling leads to a large and sparse linear system of equations that can efficiently be solved by projection methods-based iterative algorithms. Such algorithms perform projections of the iterates onto the hyperlanes that are represented by the linear equations of the system. They perform these projections in possibly various algorithmic structures, such as block-iterative projections (BIP), string-averaging...

  3. Partial-Transfer Absorption Imaging: A versatile technique for optimal imaging of ultracold gases

    CERN Document Server

    Ramanathan, Anand; Wright, Kevin C; Anderson, Russell P; Phillips, William D; Helmerson, Kristian; Campbell, Gretchen K

    2012-01-01

    Partial-transfer absorption imaging is a tool that enables optimal imaging of atomic clouds for a wide range of optical depths. In contrast to standard absorption imaging, the technique can be minimally-destructive and can be used to obtain multiple successive images of the same sample. The technique involves transferring a small fraction of the sample from an initial internal atomic state to an auxiliary state and subsequently imaging that fraction absorptively on a cycling transition. The atoms remaining in the initial state are essentially unaffected. We demonstrate the technique, discuss its applicability, and compare its performance as a minimally-destructive technique to that of phase-contrast imaging.

  4. Subclinical hyperthyroidism: current concepts and scintigraphic imaging.

    Science.gov (United States)

    Intenzo, Charles; Jabbour, Serge; Miller, Jeffrey L; Ahmed, Intekhab; Furlong, Kevin; Kushen, Medina; Kim, Sung M; Capuzzi, David M

    2011-09-01

    Subclinical hyperthyroidism is defined as normal serum free thyroxine and a free triiodothyronine level, with a thyroid-stimulating hormone level suppressed below the normal range and is usually undetectable. Although patients with this diagnosis have no or few signs and symptoms of overt thyrotoxicosis, there is sufficient evidence that it is associated with a relatively higher risk of supraventricular arrhythmias as well as the acceleration or the development of osteoporosis. Consequently, the approach to the patient with subclinical hyperthyroidism is controversial, that is, therapeutic intervention versus watchful waiting. Regardless, it is imperative for the referring physician to identify the causative thyroid disorder. This is optimally accomplished by a functional study, namely scintigraphy. Recognition of the scan findings of the various causes of subclinical hyperthyroidism enables the imaging specialist to help in diagnosing the underlying condition causing thyroid-stimulating hormone suppression thereby facilitating the workup and management of this thyroid disorder.

  5. Laser image denoising technique based on multi-fractal theory

    Science.gov (United States)

    Du, Lin; Sun, Huayan; Tian, Weiqing; Wang, Shuai

    2014-02-01

    The noise of laser images is complex, which includes additive noise and multiplicative noise. Considering the features of laser images, the basic processing capacity and defects of the common algorithm, this paper introduces the fractal theory into the research of laser image denoising. The research of laser image denoising is implemented mainly through the analysis of the singularity exponent of each pixel in fractal space and the feature of multi-fractal spectrum. According to the quantitative and qualitative evaluation of the processed image, the laser image processing technique based on fractal theory not only effectively removes the complicated noise of the laser images obtained by range-gated laser active imaging system, but can also maintains the detail information when implementing the image denoising processing. For different laser images, multi-fractal denoising technique can increase SNR of the laser image at least 1~2dB compared with other denoising techniques, which basically meet the needs of the laser image denoising technique.

  6. Millimeter-wave Imaging Systems with Aperture Synthesis Techniques

    DEFF Research Database (Denmark)

    Löffler, Torsten; Krozer, Viktor; Zhurbenko, Vitaliy;

    2010-01-01

    The paper describes development of a millimetre-wave imaging system using multi-element aperture filling techniques [1]. Such imaging systems are increasingly demonstrated for security applications and in particular standoff imaging of persons and bonding flaw and defect detection [2]. The major...

  7. Technique for identifying, tracing, or tracking objects in image data

    Science.gov (United States)

    Anderson, Robert J.; Rothganger, Fredrick

    2012-08-28

    A technique for computer vision uses a polygon contour to trace an object. The technique includes rendering a polygon contour superimposed over a first frame of image data. The polygon contour is iteratively refined to more accurately trace the object within the first frame after each iteration. The refinement includes computing image energies along lengths of contour lines of the polygon contour and adjusting positions of the contour lines based at least in part on the image energies.

  8. An Efficient Image Compression Technique Based on Arithmetic Coding

    Directory of Open Access Journals (Sweden)

    Prof. Rajendra Kumar Patel

    2012-12-01

    Full Text Available The rapid growth of digital imaging applications, including desktop publishing, multimedia, teleconferencing, and high visual definition has increased the need for effective and standardized image compression techniques. Digital Images play a very important role for describing the detailed information. The key obstacle for many applications is the vast amount of data required to represent a digital image directly. The various processes of digitizing the images to obtain it in the best quality for the more clear and accurate information leads to the requirement of more storage space and better storage and accessing mechanism in the form of hardware or software. In this paper we concentrate mainly on the above flaw so that we reduce the space with best quality image compression. State-ofthe-art techniques can compress typical images from 1/10 to 1/50 their uncompressed size without visibly affecting image quality. From our study I observe that there is a need of good image compression technique which provides better reduction technique in terms of storage and quality. Arithmetic coding is the best way to reducing encoding data. So in this paper we propose arithmetic coding with walsh transformation based image compression technique which is an efficient way of reduction

  9. An Effective Method of Image Retrieval using Image Mining Techniques

    OpenAIRE

    Kannan, A.; Dr.V.Mohan; Dr.N.Anbazhagan

    2010-01-01

    The present research scholars are having keen interest in doing their research activities in the area of Data mining all over the world. Especially, [13]Mining Image data is the one of the essential features in this present scenario since image data plays vital role in every aspect of the system such as business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-Based Image Retrieval (CB...

  10. Failure Analysis of CCD Image Sensors Using SQUID and GMR Magnetic Current Imaging

    Science.gov (United States)

    Felt, Frederick S.

    2005-01-01

    During electrical testing of a Full Field CCD Image Senor, electrical shorts were detected on three of six devices. These failures occurred after the parts were soldered to the PCB. Failure analysis was performed to determine the cause and locations of these failures on the devices. After removing the fiber optic faceplate, optical inspection was performed on the CCDs to understand the design and package layout. Optical inspection revealed that the device had a light shield ringing the CCD array. This structure complicated the failure analysis. Alternate methods of analysis were considered, including liquid crystal, light and thermal emission, LT/A, TT/A SQUID, and MP. Of these, SQUID and MP techniques were pursued for further analysis. Also magnetoresistive current imaging technology is discussed and compared to SQUID.

  11. New imaging techniques and opportunities in endoscopy.

    Science.gov (United States)

    Kiesslich, Ralf; Goetz, Martin; Hoffman, Arthur; Galle, Peter Robert

    2011-09-06

    Gastrointestinal endoscopy is undergoing major improvements, which are driven by new available technologies and substantial refinements of optical features. In this Review, we summarize available and evolving imaging technologies that could influence the clinical algorithm of endoscopic diagnosis. Detection, characterization and confirmation are essential steps required for proper endoscopic diagnosis. Optical and nonoptical methods can help to improve each step; these improvements are likely to increase the detection rate of neoplasias and reduce unnecessary endoscopic treatments. Furthermore, functional and molecular imaging are emerging as new diagnostic tools that could provide an opportunity for personalized medicine, in which endoscopy will define disease outcome or predict the response to targeted therapy.

  12. Image Reversal Techniques With Standard Positive Photoresist

    Science.gov (United States)

    Long, Mary L.; Newman, Jeff

    1984-05-01

    The basic reaction of positive photoresist involves the conversion of the dissolution inhibitor (diazoketone) to a dissolution enhancer (carboxylic acid). The novolac-type resin is basically unchanged, but its solubility is controlled by the presence of either the dissolution inhibitor or enhancer. It has been demonstrated that the dissolution enhancer can be thermally degraded, and, under the proper conditions, this degradation can lead to the reversal of the resist image. It is, of course, imperative to optimize the developer selectivity and to capitalize on the specific characteristics of common positive resists to define a production-oriented image reversal process.**

  13. Technique of Hadamard transform microscope fluorescence image analysis

    Institute of Scientific and Technical Information of China (English)

    梅二文; 顾文芳; 曾晓斌; 陈观铨; 曾云鹗

    1995-01-01

    Hadamard transform spatial multiplexed imaging technique is combined with fluorescence microscope and an instrument of Hadamard transform microscope fluorescence image analysis is developed. Images acquired by this instrument can provide a lot of useful information simultaneously, including three-dimensional Hadamard transform microscope cell fluorescence image, the fluorescence intensity and fluorescence distribution of a cell, the background signal intensity and the signal/noise ratio, etc.

  14. Full Parallax Integral 3D Display and Image Processing Techniques

    Directory of Open Access Journals (Sweden)

    Byung-Gook Lee

    2015-02-01

    Full Text Available Purpose – Full parallax integral 3D display is one of the promising future displays that provide different perspectives according to viewing direction. In this paper, the authors review the recent integral 3D display and image processing techniques for improving the performance, such as viewing resolution, viewing angle, etc.Design/methodology/approach – Firstly, to improve the viewing resolution of 3D images in the integral imaging display with lenslet array, the authors present 3D integral imaging display with focused mode using the time-multiplexed display. Compared with the original integral imaging with focused mode, the authors use the electrical masks and the corresponding elemental image set. In this system, the authors can generate the resolution-improved 3D images with the n×n pixels from each lenslet by using n×n time-multiplexed display. Secondly, a new image processing technique related to the elemental image generation for 3D scenes is presented. With the information provided by the Kinect device, the array of elemental images for an integral imaging display is generated.Findings – From their first work, the authors improved the resolution of 3D images by using the time-multiplexing technique through the demonstration of the 24 inch integral imaging system. Authors’ method can be applied to a practical application. Next, the proposed method with the Kinect device can gain a competitive advantage over other methods for the capture of integral images of big 3D scenes. The main advantage of fusing the Kinect and the integral imaging concepts is the acquisition speed, and the small amount of handled data.Originality / Value – In this paper, the authors review their recent methods related to integral 3D display and image processing technique.Research type – general review.

  15. A New Image Steganography Based On First Component Alteration Technique

    CERN Document Server

    Kaur, Amanpreet; Sikka, Geeta

    2010-01-01

    In this paper, A new image steganography scheme is proposed which is a kind of spatial domain technique. In order to hide secret data in cover-image, the first component alteration technique is used. Techniques used so far focuses only on the two or four bits of a pixel in a image (at the most five bits at the edge of an image) which results in less peak to signal noise ratio and high root mean square error. In this technique, 8 bits of blue components of pixels are replaced with secret data bits. Proposed scheme can embed more data than previous schemes and shows better image quality. To prove this scheme, several experiments are performed, and are compared the experimental results with the related previous works.

  16. An image processing technique for the radiographic assessment of vertebral derangements

    Energy Technology Data Exchange (ETDEWEB)

    Breen, A.C. (Anglo-European Coll. of Chiropractic, Bournemouth (UK)); Allen, R. (Southampton Univ. (UK). Dept. of Mechanical Engineering); Morris, A. (Odstock Hospital, Salisbury (UK). Dept. of Radiology)

    1989-01-01

    A technique for measuring inter-vertebral motion by the digitization and processing of intensifier images is described. The technique reduces the time and X-ray dosage currently required to make such assessments. The errors associated with computing kinematic indices at increments of coronal plane rotations in the lumbar spine have been calculated using a calibration model designed to produce a facsimile of in vivo conditions in terms of image quality and geometric distortion. (author).

  17. Effect of Enhancement Technique on Nonuniform and Uniform Ultrasound Images

    Directory of Open Access Journals (Sweden)

    Parveen Lehana

    2015-01-01

    Full Text Available The absence of adequate scientific resources in the area of medical sciences sometimes leads to improper diagnosis of diseases and hence the treatments of such diseases are affected badly. However, with the advancement of technology, the complicacy of various malfunctions inside the human body reduces. Ultrasound imaging is one of the biomedical scanning techniques that let the pathologist make comment reasonably and accurately on the disease or irregularity seen in the scan while low imaging quality lets the diagnosis go wrong. Even a little distortion can route the pathologist away from the main cause of the disease. In this research work, the enhancement of dark ultrasound images has been done. An algorithm is developed using enhancement technique for nonuniform and uniform dark images. Finally, we compared the quality of the processed and unprocessed images. Both ETNUD and mean and median filtering techniques were used for image analysis.

  18. Jet-Images: Computer Vision Inspired Techniques for Jet Tagging

    CERN Document Server

    Cogan, Josh; Strauss, Emanuel; Schwarztman, Ariel

    2014-01-01

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon- initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  19. Optimization of Memory Management in Image Processing using Pipelining Technique

    Directory of Open Access Journals (Sweden)

    P.S. Ramesh

    2015-02-01

    Full Text Available The quality of the image is mainly based on the various phenomena which generally consume lots of memory that needs to be resolved addressed. The handling of the memory is mainly affected due to disorderly arranged pixels in an image. This may lead to salt and pepper noise which will affect the quality of the image. The aim of this study is to remove the salt and pepper noise which is most crucial in image processing fields. In this study, we proposed a technique which combines adaptive mean filtering technique and wavelet transform technique based on pipeline processing to remove intensity spikes from the image and then both Otsu’s and Clahe algorithms are used to enhance the image. The implemented framework produces good results and proves against salt and pepper noise using PSNR algorithm.

  20. Jet-images: computer vision inspired techniques for jet tagging

    Energy Technology Data Exchange (ETDEWEB)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel [SLAC National Accelerator Laboratory,Menlo Park, CA 94028 (United States)

    2015-02-18

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  1. Study of Ultrasound Imaging Technique for Diagnosing Osteoporosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. J.; Han, S. M. [Kyunghee University, Seoul (Korea, Republic of); Lee, J. H.; Lee, M. R. [Pusan National University, Busan (Korea, Republic of)

    2002-08-15

    Ultrasonic has been proposed as an attractive means of detecting bone loss. There have been several commercial ultrasound devices developed for measuring the heel to predict fracture at other bones. However, these devices select only single point of heel bone as measurement site. It causes poor assessment of bone quality due to the error of transducer positioning. In an effort to improve current ultrasound systems, we evaluated the linear scanning method which provides better prediction of bone quality and an accurate image of bone shape. The system used in this study biaxially scans a heel bone using automated linear scanning technique. The results demonstrated that the values of ultrasound parameters varied with different positions within bone specimen. It has been also found that the linear scanning method could better predict bone quality, eliminating the error of transducer positioning

  2. Hierarchical clustering techniques for image database organization and summarization

    Science.gov (United States)

    Vellaikal, Asha; Kuo, C.-C. Jay

    1998-10-01

    This paper investigates clustering techniques as a method of organizing image databases to support popular visual management functions such as searching, browsing and navigation. Different types of hierarchical agglomerative clustering techniques are studied as a method of organizing features space as well as summarizing image groups by the selection of a few appropriate representatives. Retrieval performance using both single and multiple level hierarchies are experimented with and the algorithms show an interesting relationship between the top k correct retrievals and the number of comparisons required. Some arguments are given to support the use of such cluster-based techniques for managing distributed image databases.

  3. Simple Augmented Current Controller with OHC Technique for grid current compensation in the Distribution System

    Directory of Open Access Journals (Sweden)

    S. Rajalingam

    2014-05-01

    Full Text Available This paper presents a novel control technique on four leg inverter with which the distribution grid is interconnected with the domestic houses. Most of the houses in the distribution side possess inverter for the usage of Electricity. With the advancement in Solar & wind, it will become easy to see houses, often with solar & a small Wind power system. The excess power generated can be exchanged with the Electricity Board for providing uninterruptible power supply. During this exchange there may be a deterioration in the quality of power, most often the grid current gets affected with a large harmonic distortion, and also there exists unbalanced grid currents. Thus, it is necessary to provide uninterruptible power supply with good quality of power. In spite of several controllers, the proposed augmented controller has its own reliability & quick response with Overall Harmonic Compensation (OHC technique which relies on DSP based filter. This Augmented based control technique with OHC is demonstrated extensively with MATLAB/Simulink simulation.

  4. Optical image segmentation using wavelet filtering techniques

    Science.gov (United States)

    Veronin, Christopher P.

    1990-12-01

    This research effort successfully implemented an automatic, optically based image segmentation scheme for locating potential targets in a cluttered FLIR image. Such a design is critical to achieve real-time segmentation and classification for machine vision applications. The segmentation scheme used in this research was based on texture discrimination and employs orientation specific, bandpass spatial filters as its main component. The orientation specific, bandpass spatial filters designed during this research include symmetrically located circular apertures implemented on heavy, black aluminum foil; cosine and sine Gabor filters implemented with detour-phase computer generated holography photoreduced onto glass slides; and symmetrically located circular apertures implemented on a liquid crystal television (LCTV) for real-time filter selection. The most successful design was the circular aperture pairs implemented on the aluminum foil. Segmentation was illustrated for simple and complex texture slides, glass template slides, and static and real-time FLIR imagery displayed on an LCTV.

  5. Multiple Myeloma: A Review of Imaging Features and Radiological Techniques

    Directory of Open Access Journals (Sweden)

    C. F. Healy

    2011-01-01

    Full Text Available The recently updated Durie/Salmon PLUS staging system published in 2006 highlights the many advances that have been made in the imaging of multiple myeloma, a common malignancy of plasma cells. In this article, we shall focus primarily on the more sensitive and specific whole-body imaging techniques, including whole-body computed tomography, whole-body magnetic resonance imaging, and positron emission computed tomography. We shall also discuss new and emerging imaging techniques and future developments in the radiological assessment of multiple myeloma.

  6. Image and video compression fundamentals, techniques, and applications

    CERN Document Server

    Joshi, Madhuri A; Dandawate, Yogesh H; Joshi, Kalyani R; Metkar, Shilpa P

    2014-01-01

    Image and video signals require large transmission bandwidth and storage, leading to high costs. The data must be compressed without a loss or with a small loss of quality. Thus, efficient image and video compression algorithms play a significant role in the storage and transmission of data.Image and Video Compression: Fundamentals, Techniques, and Applications explains the major techniques for image and video compression and demonstrates their practical implementation using MATLAB® programs. Designed for students, researchers, and practicing engineers, the book presents both basic principles

  7. A review of imaging techniques for systems biology

    Directory of Open Access Journals (Sweden)

    Po Ming J

    2008-08-01

    Full Text Available Abstract This paper presents a review of imaging techniques and of their utility in system biology. During the last decade systems biology has matured into a distinct field and imaging has been increasingly used to enable the interplay of experimental and theoretical biology. In this review, we describe and compare the roles of microscopy, ultrasound, CT (Computed Tomography, MRI (Magnetic Resonance Imaging, PET (Positron Emission Tomography, and molecular probes such as quantum dots and nanoshells in systems biology. As a unified application area among these different imaging techniques, examples in cancer targeting are highlighted.

  8. Multiple myeloma: a review of imaging features and radiological techniques.

    Science.gov (United States)

    Healy, C F; Murray, J G; Eustace, S J; Madewell, J; O'Gorman, P J; O'Sullivan, P

    2011-01-01

    The recently updated Durie/Salmon PLUS staging system published in 2006 highlights the many advances that have been made in the imaging of multiple myeloma, a common malignancy of plasma cells. In this article, we shall focus primarily on the more sensitive and specific whole-body imaging techniques, including whole-body computed tomography, whole-body magnetic resonance imaging, and positron emission computed tomography. We shall also discuss new and emerging imaging techniques and future developments in the radiological assessment of multiple myeloma.

  9. Automated thermal mapping techniques using chromatic image analysis

    Science.gov (United States)

    Buck, Gregory M.

    1989-01-01

    Thermal imaging techniques are introduced using a chromatic image analysis system and temperature sensitive coatings. These techniques are used for thermal mapping and surface heat transfer measurements on aerothermodynamic test models in hypersonic wind tunnels. Measurements are made on complex vehicle configurations in a timely manner and at minimal expense. The image analysis system uses separate wavelength filtered images to analyze surface spectral intensity data. The system was initially developed for quantitative surface temperature mapping using two-color thermographic phosphors but was found useful in interpreting phase change paint and liquid crystal data as well.

  10. Reticle defect sizing of optical proximity correction defects using SEM imaging and image analysis techniques

    Science.gov (United States)

    Zurbrick, Larry S.; Wang, Lantian; Konicek, Paul; Laird, Ellen R.

    2000-07-01

    Sizing of programmed defects on optical proximity correction (OPC) feature sis addressed using high resolution scanning electron microscope (SEM) images and image analysis techniques. A comparison and analysis of different sizing methods is made. This paper addresses the issues of OPC defect definition and discusses the experimental measurement results obtained by SEM in combination with image analysis techniques.

  11. Terahertz spectroscopy and imaging – Modern techniques and applications

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd; Cooke, David; Koch, Martin

    2011-01-01

    Over the past three decades a new spectroscopic technique with unique possibilities has emerged. Based on coherent and time-resolved detection of the electric field of ultrashort radiation bursts in the far-infrared, this technique has become known as terahertz time-domain spectroscopy (THz-TDS)....... of research, where THz spectroscopic techniques have proven to be useful research tools, and the potential for industrial applications of THz spectroscopic and imaging techniques are discussed....

  12. New approaches in intelligent image analysis techniques, methodologies and applications

    CERN Document Server

    Nakamatsu, Kazumi

    2016-01-01

    This book presents an Introduction and 11 independent chapters, which are devoted to various new approaches of intelligent image processing and analysis. The book also presents new methods, algorithms and applied systems for intelligent image processing, on the following basic topics: Methods for Hierarchical Image Decomposition; Intelligent Digital Signal Processing and Feature Extraction; Data Clustering and Visualization via Echo State Networks; Clustering of Natural Images in Automatic Image Annotation Systems; Control System for Remote Sensing Image Processing; Tissue Segmentation of MR Brain Images Sequence; Kidney Cysts Segmentation in CT Images; Audio Visual Attention Models in Mobile Robots Navigation; Local Adaptive Image Processing; Learning Techniques for Intelligent Access Control; Resolution Improvement in Acoustic Maps. Each chapter is self-contained with its own references. Some of the chapters are devoted to the theoretical aspects while the others are presenting the practical aspects and the...

  13. Comparison of Satellite Image Enhancement Techniques in Wavelet Domain

    Directory of Open Access Journals (Sweden)

    K. Narasimhan

    2012-12-01

    Full Text Available In this study, a comparison of various existing satellite image resolution enhancement techniques in wavelet domain is done. Each method is analysed quantitatively and visually. There are various wavelet domain based methods such as Wavelet Zero Padding, Dual Tree-Complex Wavelet Transform, Discrete Wavelet Transform, Cycle Spinning and Undecimated Wavelet Transform. On the basis of analysis, the most efficient method is proposed. The algorithms take the low resolution image as the input image and then wavelet transformation using daubechies (db3 is used to decompose the input image into different sub band images containing high and low frequency component. Then these subband images along with the input image are interpolated followed by combining all these images to generate a new resolution enhanced image by an inverse process.

  14. A Comparison of X-Ray Image Segmentation Techniques

    Directory of Open Access Journals (Sweden)

    STOLOJESCU-CRISAN, C.

    2013-08-01

    Full Text Available Image segmentation operation has a great importance in most medical imaging applications, by extracting anatomical structures from medical images. There are many image segmentation techniques available in the literature, each of them having advantages and disadvantages. The extraction of bone contours from X-ray images has received a considerable amount of attention in the literature recently, because they represent a vital step in the computer analysis of this kind of images. The aim of X-ray segmentation is to subdivide the image in various portions, so that it can help doctors during the study of the bone structure, for the detection of fractures in bones, or for planning the treatment before surgery. The goal of this paper is to review the most important image segmentation methods starting from a data base composed by real X-ray images. We will discuss the principle and the mathematical model for each method, highlighting the strengths and weaknesses.

  15. Optical double image encryption employing a pseudo image technique in the Fourier domain

    Science.gov (United States)

    Guo, Changliang; Liu, Shi; Sheridan, John T.

    2014-06-01

    A novel optical encryption method is proposed involving double image encryption in which one image is introduced as the pseudo image while the other is the original object image. The Double Random Phase Encoding technique is used to encrypt both the pseudo and object images into complex images. A unique binary image is then employed to first generate the random phase key for the object image encryption and then to embed the encrypted object image into the encrypted pseudo image, which acts as host image. Both the second random phase mask used for encoding the pseudo image and the binary image act as encryption keys. If an attacker attempts to crack the random phase key and decrypt the original object image, the pseudo image will be obtained instead. Simulation results and robustness tests are performed which demonstrate the feasibility of the algorithm.

  16. Analysis of reliability metrics and quality enhancement measures in current density imaging.

    Science.gov (United States)

    Foomany, F H; Beheshti, M; Magtibay, K; Masse, S; Foltz, W; Sevaptsidis, E; Lai, P; Jaffray, D A; Krishnan, S; Nanthakumar, K; Umapathy, K

    2013-01-01

    Low frequency current density imaging (LFCDI) is a magnetic resonance imaging (MRI) technique which enables calculation of current pathways within the medium of study. The induced current produces a magnetic flux which presents itself in phase images obtained through MRI scanning. A class of LFCDI challenges arises from the subject rotation requirement, which calls for reliability analysis metrics and specific image registration techniques. In this study these challenges are formulated and in light of proposed discussions, the reliability analysis of calculation of current pathways in a designed phantom and a pig heart is presented. The current passed is measured with less than 5% error for phantom, using CDI method. It is shown that Gauss's law for magnetism can be treated as reliability metric in matching the images in two orientations. For the phantom and pig heart the usefulness of image registration for mitigation of rotation errors is demonstrated. The reliability metric provides a good representation of the degree of correspondence between images in two orientations for phantom and pig heart. In our CDI experiments this metric produced values of 95% and 26%, for phantom, and 88% and 75% for pig heart, for mismatch rotations of 0 and 20 degrees respectively.

  17. Visualization of sound generation: special imaging techniques

    Science.gov (United States)

    Hahlweg, Cornelius F.; Skaloud, Daniel C.; Gutzmann, Holger L.; Kutz, Sascha; Rothe, Hendrik

    2013-09-01

    The present paper is dedicated to the Optics and Music session of the Novel Systems Design and Optimization XVI Conference. It is intended as an informative paper for the music enthusiasts. Included are some examples of visualization of sound generation and vibration modes of musically relevant objects and processes - record playback, an electric guitar and a wine glass - using high speed video, borescopic view and cross polarization techniques.

  18. A New Image Fusion Technique to Improve the Quality of Remote Sensing images

    Directory of Open Access Journals (Sweden)

    Aboubaker Milad Ahmed

    2013-01-01

    Full Text Available Image fusion is a process of producing a single fused image from a set of input images. In this paper a new fusion technique based on the use of independent component analysis (ICA and IHS transformation is proposed. A comparison of this new technique with PCA, IHS, and ICA-based fusion techniques is given. Quick Bird data are used to test these techniques, the output was evaluated using subjective comparison, statistical correlation, information entropy, mean square error, and standard deviation. The results of the proposed technique show higher performance compared to the other techniques.

  19. Technique development for photoacoustic imaging guided interventions

    Science.gov (United States)

    Cheng, Qian; Zhang, Haonan; Yuan, Jie; Feng, Ting; Xu, Guan; Wang, Xueding

    2015-03-01

    Laser-induced thermotherapy (LITT), i.e. tissue destruction induced by a local increase of temperature by means of laser light energy transmission, has been frequently used for minimally invasive treatments of various diseases such as benign thyroid nodules and liver cancer. The emerging photoacoustic (PA) imaging, when integrated with ultrasound (US), could contribute to LITT procedure. PA can enable a good visualization of percutaneous apparatus deep inside tissue and, therefore, can offer accurate guidance of the optical fibers to the target tissue. Our initial experiment demonstrated that, by picking the strong photoacoustic signals generated at the tips of optical fibers as a needle, the trajectory and position of the fibers could be visualized clearly using a commercial available US unit. When working the conventional US Bscan mode, the fibers disappeared when the angle between the fibers and the probe surface was larger than 60 degree; while working on the new PA mode, the fibers could be visualized without any problem even when the angle between the fibers and the probe surface was larger than 75 degree. Moreover, with PA imaging function integrated, the optical fibers positioned into the target tissue, besides delivering optical energy for thermotherapy, can also be used to generate PA signals for on-line evaluation of LITT. Powered by our recently developed PA physio-chemical analysis, PA measurements from the tissue can provide a direct and accurate feedback of the tissue responses to laser ablation, including the changes in not only chemical compositions but also histological microstructures. The initial experiment on the rat liver model has demonstrated the excellent sensitivity of PA imaging to the changes in tissue temperature rise and tissue status (from native to coagulated) when the tissue is treated in vivo with LITT.

  20. An Useful Information Extraction using Image Mining Techniques from Remotely Sensed Image (RSI)

    OpenAIRE

    Dr. C. Jothi Venkateswaran,; Murugan, S.; Dr. N. Radhakrishnan

    2010-01-01

    Information extraction using mining techniques from remote sensing image (RSI) is rapidly gaining attention among researchers and decision makers because of its potential in application oriented studies. Knowledge discovery from image poses many interesting challenges such as preprocessing the image data set, training the data and discovering useful image patterns applicable to many newapplication frontiers. In the image rich domain of RSI, image mining implies the synergy of data mining and ...

  1. CATEGORICAL IMAGE COMPONENTS IN THE FORMING SYSTEM OF A MARKETING TECHNIQUES MANAGER’S IMAGE CULTURE

    OpenAIRE

    Anna Borisovna Cherednyakova

    2015-01-01

    Based on the understanding of the image culture formation of managers of marketing techniques, as a representative of the social and communication interaction of public structures, categorical apparatus of image culture with an emphasis on the etymology of the image, as an integral component of image culture was analyzed. Categorical components of the image are presented from the standpoint of image culture, as personal new formation, an integral part of the professional activity of the marke...

  2. Imaging in primary penile cancer: current status and future directions

    Energy Technology Data Exchange (ETDEWEB)

    Kochhar, Rohit; Taylor, Ben [Christie, NHS Foundation Trust, Department of Radiology, Manchester (United Kingdom); Sangar, Vijay [Christie, NHS Foundation Trust, Department of Urology, Manchester (United Kingdom)

    2010-01-15

    Penile cancer is a rare neoplasm in the developed world. Clinical assessment often results in inaccurate staging and radiological techniques have a key role in staging and postoperative assessment. Magnetic resonance imaging (MRI) depicts penile anatomy in detail and is the most accurate technique for local staging and postoperative follow-up. MRI and ultrasound (US), although helpful for assessment of lymph nodes, are not reliable enough for accurate nodal staging. US-guided fine needle aspiration cytology (FNAC), however, remains a valuable tool to confirm metastases in suspicious inguinal nodes. Lymphoscintigraphy with dynamic sentinel node biopsy (DSNB) is a promising technique used to predict occult lymph node metastases. Novel imaging techniques such as positron emission tomography/computed tomography (PET-CT) and nanoparticle enhanced MRI have high sensitivity and specificity for lymph node metastases but their availability is limited and clinical utility is not fully established. The radiologist needs to be familiar with the normal penile anatomy, imaging appearances of pre- and post-treatment penile cancer, and the advantages and limitations of the available imaging techniques. This review highlights the above points and presents a systematic approach to make the best use of imaging in the management of patients with penile cancer. (orig.)

  3. An improved technique for the prediction of optimal image resolution ...

    African Journals Online (AJOL)

    user

    2010-10-04

    Oct 4, 2010 ... Key words: Optimal resolution, savannah ecosystems, image noise index, land cover index, .... Most techniques, including those employed by Mugisha .... Resampling imagery using cubic convolution was used because it.

  4. Segmentation techniques for extracting humans from thermal images

    CSIR Research Space (South Africa)

    Dickens, JS

    2011-11-01

    Full Text Available A pedestrian detection system for underground mine vehicles is being developed that requires the segmentation of people from thermal images in underground mine tunnels. A number of thresholding techniques are outlined and their performance on a...

  5. Colored Digital Image Watermarking using the Wavelet Technique

    Directory of Open Access Journals (Sweden)

    Mohammed F. Al-Hunaity

    2007-01-01

    Full Text Available With the revolution of information technology and Wide Area Networking, data has become less and less private where the access of media as well as the attempts to change and manipulate the contents of media data have become a common case. For that, we need to use a watermarking technique to protect the copyright of the media as well as for digital right management but without leaving a visual effect. We presented a watermarking technique that deals with images where the used technique to embed a wavelet compressed watermark image within the least significant bit (LSB of the cover image pixels in a specific pattern which won't be visible after embedding and will cause the cover image to become copyrighted using the embedded watermark image that can be extracted later.

  6. Evaluation of lung tumor response to therapy: Current and emerging techniques.

    Science.gov (United States)

    Coche, E

    2016-10-01

    Lung tumor response to therapy may be evaluated in most instances by morphological criteria such as RECIST 1.1 on computed tomography (CT) or magnetic resonance imaging (MRI). However, those criteria are limited because they are based on tumoral dimensional changes and do not take into account other morphologic criteria such as density evaluation, functional or metabolic changes that may occur following conventional or targeted chemotherapy. New techniques such as dual-energy CT, PET-CT, MRI including diffusion-weighted MRI has to be considered into the new technical armamentarium for tumor response evaluation. Integration of all informations provided by the different imaging modalities has to be integrated and represents probably the future goal of tumor response evaluation. The aim of the present paper is to review the current and emerging imaging criteria used to evaluate the response of therapy in the field of lung cancer.

  7. Extraction of Information from Images using Dewrapping Techniques

    Directory of Open Access Journals (Sweden)

    Khalid Nazim S. A.

    2010-11-01

    Full Text Available An image containing textual information is called a document image. The textual information in document images is useful in areas like vehicle number plate reading, passport reading and cargo container reading and so on. Thus extracting useful textual information in the document image plays an important role in many applications. One of the major challenges in camera document analysis is to deal with the wrap and perspective distortions. In spite of the prevalence of dewrapping techniques, there is no standard efficient algorithm for the performance evaluation that concentrates on visualization. Wrapping is a common appearance document image before recognition. In order to capture the document images a mobile camera of 2megapixel resolution is used. A database is developed with variations in background, size and colour along with wrapped images, blurred and clean images. This database will be explored and text extraction from those document images is performed. In case of wrapped images no efficient dewrapping techniques have been implemented till date. Thus extracting the text from the wrapped images is done by maintaining a suitable template database. Further, the extracted text from the wrapped or other document images will be converted into an editable form such as Notepad or MS word document. The experimental results were corroborated on various objects of database.

  8. Bore hole image well logging technique

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Young Kwon; Kim, Geon Young; Bae, Dae Seok; Kim, Kyung Su; Ryu, Ji Hoon; Park, Kyung Woo; Ji, Sung Hoon

    2009-08-15

    As one of the investigation method which the underground geological features is direct drill investigation geological features condition of underground directness it will can confirm visually there is a strong point but the drill nose in compliance with war potential or a shock from the digging through process which it knows the orientation scattering, or, the capital where the destruction action which is mechanical will accompany it will be, also to the case where the ground condition is defective the nose Oh there is a possibility of being difficult also oneself getting to the evaluation which ground is accurate with being difficult, it operated and it was come. As the method which solves like this problem drill worker image photographing which is the possibility of getting the burn was introduced in about the drill worker wall. Drill worker image photographing it will be able to classify with 3 kind of electricity, the sound wave and optical science etc. on a large scale and these people are controlled and respectively amplitude and staring reaction of electric resistivity reaction and the sound wave, in order for the pixel price which digitizes optical science photograph etc. to confront clearly in spatial location it will be able to provide information concretely about rock floor etc., discontinuity surface situation and of the public wall travelling and inclination and the clearance

  9. Coded Aperture Nuclear Scintigraphy: A Novel Small Animal Imaging Technique

    Directory of Open Access Journals (Sweden)

    Dawid Schellingerhout

    2002-10-01

    Full Text Available We introduce and demonstrate the utility of coded aperture (CA nuclear scintigraphy for imaging small animals. CA imaging uses multiple pinholes in a carefully designed mask pattern, mounted on a conventional gamma camera. System performance was assessed using point sources and phantoms, while several animal experiments were performed to test the usefulness of the imaging system in vivo, with commonly used radiopharmaceuticals. The sensitivity of the CA system for 99mTc was 4.2 × 103 cps/Bq (9400 cpm/μCi, compared to 4.4 × 104 cps/Bq (990 cpm/μCi for a conventional collimator system. The system resolution was 1.7 mm, as compared to 4–6 mm for the conventional imaging system (using a high-sensitivity low-energy collimator. Animal imaging demonstrated artifact-free imaging with superior resolution and image quality compared to conventional collimator images in several mouse and rat models. We conclude that: (a CA imaging is a useful nuclear imaging technique for small animal imaging. The advantage in signal-to-noise can be traded to achieve higher resolution, decreased dose or reduced imaging time. (b CA imaging works best for images where activity is concentrated in small volumes; a low count outline may be better demonstrated using conventional collimator imaging. Thus, CA imaging should be viewed as a technique to complement rather than replace traditional nuclear imaging methods. (c CA hardware and software can be readily adapted to existing gamma cameras, making their implementation a relatively inexpensive retrofit to most systems.

  10. Optical and digital microscopic imaging techniques and applications in pathology.

    Science.gov (United States)

    Chen, Xiaodong; Zheng, Bin; Liu, Hong

    2011-01-01

    The conventional optical microscope has been the primary tool in assisting pathological examinations. The modern digital pathology combines the power of microscopy, electronic detection, and computerized analysis. It enables cellular-, molecular-, and genetic-imaging at high efficiency and accuracy to facilitate clinical screening and diagnosis. This paper first reviews the fundamental concepts of microscopic imaging and introduces the technical features and associated clinical applications of optical microscopes, electron microscopes, scanning tunnel microscopes, and fluorescence microscopes. The interface of microscopy with digital image acquisition methods is discussed. The recent developments and future perspectives of contemporary microscopic imaging techniques such as three-dimensional and in vivo imaging are analyzed for their clinical potentials.

  11. Image guided robotic surgery: Current evidence for effectiveness in urology

    Directory of Open Access Journals (Sweden)

    Anum Pervez

    2014-12-01

    Full Text Available Objectives: Discussion of the evolution of image guided surgery (IGS and its fundamental components and current evidence for effectiveness of IGS in clinical urology. Methods: Literature search for image-guided robotic urology. Results: Current literature in image-guided robotic urology with its use in robot assisted radical prostatectomy and robot assisted partial nephrectomy are shown. Conclusions: Image guided surgery can be a useful aid to improve visualisation of anatomy and subsurface structures during minimally invasive surgery. Soft-tissue deformation makes it difficult to implement IGS in urology but current studies have shown an attempt to address this issue. The feasibility of IGS requires randomised control trials assessing in particular its accuracy and affect on clinical outcome.

  12. CATEGORICAL IMAGE COMPONENTS IN THE FORMING SYSTEM OF A MARKETING TECHNIQUES MANAGER’S IMAGE CULTURE

    Directory of Open Access Journals (Sweden)

    Anna Borisovna Cherednyakova

    2015-08-01

    Full Text Available Based on the understanding of the image culture formation of managers of marketing techniques, as a representative of the social and communication interaction of public structures, categorical apparatus of image culture with an emphasis on the etymology of the image, as an integral component of image culture was analyzed. Categorical components of the image are presented from the standpoint of image culture, as personal new formation, an integral part of the professional activity of the marketing techniques manager: object-communicative categorical component, subject-activity categorical component of image, personality-oriented categorical component, value-acmeological categorical component of image.The aim is to identify and justify the image categorical components as a component of image culture of the marketing techniques manager.Method and methodology of work – a general scientific research approach reflecting scientific apparatus of research.Results. Categorical components of the image, as an image culture component of manager of marketing techniques were defined.Practical implication of the results. The theoretical part of «Imageology» course, special course «Image culture of manager of marketing techniques», the theoretical and methodological study and the formation of image culture.

  13. Detection of localized damage by eddy currents technique

    Directory of Open Access Journals (Sweden)

    Aoukili A.

    2014-01-01

    Full Text Available Non destructive evaluation techniques based on eddy currents (EC are largely used for quality control of the castings in a lot of industries. The principle of detection by EC consists in using an adequate inductive coil to generate them by a variable magnetic field, and measuring their effects by using one or several sensors. These effects result from the interaction between the induced magnetic field and the excited conductive material. A local variation of the physical properties or geometry of the tested sample, due to a singularity or a flaw, causes a modification of the EC distribution, enabling thus detection. In order to optimize the capacity of defect revealing by means of EC based probes, an accurate modelling of the problem is essential. This can be used to perform simulation of the EC distribution under different circumstances and to analyze the EC sensitivity to the various implicated parameters. In this work, the modelling of EC is made by using the finite element method. Using a B-scan strategy was used, detection of a small defect having the shape of an open cavity is shown to be correctly indicated via monitoring variations of the induced voltage in the receiver coil.

  14. Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods.

    Science.gov (United States)

    Fantini, Sergio; Sassaroli, Angelo; Tgavalekos, Kristen T; Kornbluth, Joshua

    2016-07-01

    Cerebral blood flow (CBF) and cerebral autoregulation (CA) are critically important to maintain proper brain perfusion and supply the brain with the necessary oxygen and energy substrates. Adequate brain perfusion is required to support normal brain function, to achieve successful aging, and to navigate acute and chronic medical conditions. We review the general principles of CBF measurements and the current techniques to measure CBF based on direct intravascular measurements, nuclear medicine, X-ray imaging, magnetic resonance imaging, ultrasound techniques, thermal diffusion, and optical methods. We also review techniques for arterial blood pressure measurements as well as theoretical and experimental methods for the assessment of CA, including recent approaches based on optical techniques. The assessment of cerebral perfusion in the clinical practice is also presented. The comprehensive description of principles, methods, and clinical requirements of CBF and CA measurements highlights the potentially important role that noninvasive optical methods can play in the assessment of neurovascular health. In fact, optical techniques have the ability to provide a noninvasive, quantitative, and continuous monitor of CBF and autoregulation.

  15. High-temperature strain measurement techniques: Current developments and challenges

    Science.gov (United States)

    Lemcoe, M. M.

    1992-01-01

    Since 1987, a very substantial amount of R&D has been conducted in an attempt to develop reliable strain sensors for the measurements of structural strains during ground testing and hypersonic flight, at temperatures up to at least 2000 deg F. Much of the effort has been focused on requirements of the NASP Program. This presentation is limited to the current sensor development work and characterization studies carried out within that program. It is basically an assessment as to where we are now and what remains to be done in the way of technical accomplishments to meet the technical challenges posed by the requirements and constraints established for the NASP Program. The approach for meeting those requirements and constraints has been multi-disciplinary in nature. It was recognized early on that no one sensor could meet all these requirements and constraints, largely because of the large temperature range (cryogenic to at least 2000 deg F) and many other factors, including the most challenging requirement that the sensor system be capable of obtaining valid 'first cycle data'. Present candidate alloys for resistance-type strain gages include Fe-Cr-Al and Pd-Cr. Although they have superior properties regarding withstanding very high temperatures, they exhibit large apparent strains that must either be accounted for or cancelled out by various techniques, including the use of a dual-element, half-bridge dummy gage, or electrical compensation networks. A significant effort is being devoted to developing, refining, and evaluating the effectiveness of those techniques over a broad range in temperature and time. In the quest to obtain first-cycle data, ways must be found to eliminate the need to prestabilize or precondition the strain gage, before it is attached to the test article. It should be noted that present NASP constraints do not permit prestabilization of the sensor, in situ. Gages are currently being 'heat treated' during manufacture in both the wire- and foil

  16. An Useful Information Extraction using Image Mining Techniques from Remotely Sensed Image (RSI

    Directory of Open Access Journals (Sweden)

    Dr. C. Jothi Venkateswaran,

    2010-11-01

    Full Text Available Information extraction using mining techniques from remote sensing image (RSI is rapidly gaining attention among researchers and decision makers because of its potential in application oriented studies. Knowledge discovery from image poses many interesting challenges such as preprocessing the image data set, training the data and discovering useful image patterns applicable to many newapplication frontiers. In the image rich domain of RSI, image mining implies the synergy of data mining and image processing technology. Such culmination of techniques renders a valuable tool in information extraction. Also, this encompasses the problem of handling a larger data base of varied image data formats representing various levels ofinformation such as pixel, local and regional. In the present paper, various preprocessing corrections and techniques of image mining are discussed.

  17. Orbital Differential Imaging: A New High-Contrast Post-Processing Technique For Direct Imaging of Exoplanets

    CERN Document Server

    Males, Jared R; Bendek, Eduardo

    2015-01-01

    Current post-processing techniques in high contrast imaging depend on some source of diversity between the exoplanet signal and the residual star light at that location. The two main techniques are angular differential imaging (ADI), which makes use of parallactic sky rotation to separate planet from star light, and spectral differential imaging (SDI), which makes use of differences in the spectrum of planet and star light and the wavelength dependence of the point spread function (PSF). Here we introduce our technique for exploiting another source of diversity: orbital motion. Given repeated observations of an exoplanetary system with sufficiently short orbital periods, the motion of the planets allows us to discriminate them from the PSF. In addition to using powerful PSF subtraction algorithms, such an observing strategy enables temporal filtering. Once an orbit is determined, the planet can be ``de-orbited'' to further increase the signal-to-noise ratio. We call this collection of techniques Orbital Diffe...

  18. The molecular imaging approach to image infections and inflammation by nuclear medicine techniques

    NARCIS (Netherlands)

    Signore, Alberto; Glaudemans, Andor W. J. M.

    2011-01-01

    Inflammatory and infectious diseases are a heterogeneous class of diseases that may be divided into infections, acute inflammation and chronic inflammation. Radiological imaging techniques have, with the exception of functional MRI, high sensitivity but lack in specificity. Nuclear medicine techniqu

  19. Cardiac magnetic source imaging based on current multipole model

    Institute of Scientific and Technical Information of China (English)

    Tang Fa-Kuan; Wang Qian; Hua Ning; Lu Hong; Tang Xue-Zheng; Ma Ping

    2011-01-01

    It is widely accepted that the heart current source can be reduced into a current multipole. By adopting three linear inverse methods, the cardiac magnetic imaging is achieved in this article based on the current multipole model expanded to the first order terms. This magnetic imaging is realized in a reconstruction plane in the centre of human heart, where the current dipole array is employed to represent realistic cardiac current distribution. The current multipole as testing source generates magnetic fields in the measuring plane, serving as inputs of cardiac magnetic inverse problem. In the heart-torso model constructed by boundary element method, the current multipole magnetic field distribution is compared with that in the homogeneous infinite space, and also with the single current dipole magnetic field distribution.Then the minimum-norm least-squares (MNLS) method, the optimal weighted pseuDOInverse method (OWPIM), and the optimal constrained linear inverse method (OCLIM) are selected as the algorithms for inverse computation based on current multipole model innovatively, and the imaging effects of these three inverse methods are compared. Besides,two reconstructing parameters, residual and mean residual, are also discussed, and their trends under MNLS, OWPIM and OCLIM each as a function of SNR are obtained and compared.

  20. Magnetic resonance electrical impedance tomography (MREIT): conductivity and current density imaging

    Science.gov (United States)

    Seo, Jin Keun; Kwon, Ohin; Woo, Eung Je

    2005-01-01

    This paper reviews the latest impedance imaging technique called Magnetic Resonance Electrical Impedance Tomography (MREIT) providing information on electrical conductivity and current density distributions inside an electrically conducting domain such as the human body. The motivation for this research is explained by discussing conductivity changes related with physiological and pathological events, electromagnetic source imaging and electromagnetic stimulations. We briefly summarize the related technique of Electrical Impedance Tomography (EIT) that deals with cross-sectional image reconstructions of conductivity distributions from boundary measurements of current-voltage data. Noting that EIT suffers from the ill-posed nature of the corresponding inverse problem, we introduce MREIT as a new conductivity imaging modality providing images with better spatial resolution and accuracy. MREIT utilizes internal information on the induced magnetic field in addition to the boundary current-voltage measurements to produce three-dimensional images of conductivity and current density distributions. Mathematical theory, algorithms, and experimental methods of current MREIT research are described. With numerous potential applications in mind, future research directions in MREIT are proposed.

  1. Imaging of lumbar degenerative disk disease: history and current state

    Energy Technology Data Exchange (ETDEWEB)

    Emch, Todd M. [Cleveland Clinic, Division of Neuroradiology, Imaging Institute, Neuroradiology L-10, Cleveland, OH (United States); Modic, Michael T. [Cleveland Clinic, Division of Neuroradiology, Imaging Institute, Neurological Institute T-13, Cleveland, OH (United States)

    2011-09-15

    One of the most common indications for performing magnetic resonance (MR) imaging of the lumbar spine is the symptom complex thought to originate as a result of degenerative disk disease. MR imaging, which has emerged as perhaps the modality of choice for imaging degenerative disk disease, can readily demonstrate disk pathology, degenerative endplate changes, facet and ligamentous hypertrophic changes, and the sequelae of instability. Its role in terms of predicting natural history of low back pain, identifying causality, or offering prognostic information is unclear. As available modalities for imaging the spine have progressed from radiography, myelography, and computed tomography to MR imaging, there have also been advances in spine surgery for degenerative disk disease. These advances are described in a temporal context for historical purposes with a focus on MR imaging's history and current state. (orig.)

  2. Muscle perfusion and metabolic heterogeneity: insights from noninvasive imaging techniques

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Scheede-Bergdahl, Celena; Kjaer, Michael

    2006-01-01

    Recent developments in noninvasive imaging techniques have enabled the study of local changes in perfusion and metabolism in skeletal muscle as well as patterns of heterogeneity in these variables in humans. In this review, the principles of these techniques along with some recent findings on fun...

  3. Techniques and software architectures for medical visualisation and image processing

    NARCIS (Netherlands)

    Botha, C.P.

    2005-01-01

    This thesis presents a flexible software platform for medical visualisation and image processing, a technique for the segmentation of the shoulder skeleton from CT data and three techniques that make contributions to the field of direct volume rendering. Our primary goal was to investigate the use

  4. Imaging Atmospheric Cerenkov Telescopes Techniques and Results

    CERN Document Server

    Bradbury, S M

    2001-01-01

    The hunt for cosmic TeV particle accelerators is prospering through Imaging Atmospheric Cerenkov Telescopes. We face challenges such as low light levels and MHz trigger rates, and the need to distinguish between particle air showers stemming from primary gamma rays and those due to the hadronic cosmic ray background. Our test beam is provided by the Crab Nebula, a steady accelerator of particles to energies beyond 20 TeV. Highly variable gamma-ray emission, coincident with flares at longer wavelengths, is revealing the particle acceleration mechanisms at work in the relativistic jets of Active Galaxies. These 200 GeV to 20 TeV photons propagating over cosmological distances allow us to place a limit on the infra-red background linked to galaxy formation and, some speculate, to the decay of massive relic neutrinos. Gamma rays produced in neutralino annihilation or the evaporation of primordial black holes may also be detectable. These phenomena and a zoo of astrophysical objects will be the targets of the next...

  5. Improving Seismic Image with Advanced Processing Techniques

    Directory of Open Access Journals (Sweden)

    Mericy Lastra Cunill

    2012-07-01

    Full Text Available Taking Taking into account the need to improve the seismic image in the central area of Cuba, specifically in the area of the Venegas sector, located in the Cuban Folded Belt, the seismic data acquired by Cuba Petróleo (CUPET in the year 2007 was reprocessed according to the experience accumulated during the previous processing carried out in the same year, and the new geologic knowledge on the area. This was done with the objective of improving the results. The processing applied previously was analyzed by reprocessing the primary data with new focuses and procedures, among them are the following: the attenuation of the superficial wave with a filter in the Radon domain in its lineal variant, the change of the primary statics corrections of elevation by those of refraction, the study of velocity with the selection automatic biespectral of high density, the study of the anisotropy, the attenuation of the random noise, and the pre stack time and depth migration. As a result of this reprocessing, a structure that was not identified in the seismic sections of the previous processing was located at the top of a Continental Margin sediment located to the north of the sector that increased the potentialities of finding hydrocarbons in quantities of economic importance thus diminishing the risk of drilling in the sector Venegas.

  6. Improved LSB Steganograhy Technique for grayscale and RGB images

    Directory of Open Access Journals (Sweden)

    Raju

    2014-10-01

    Full Text Available A number of techniques are there to converse securely. Encryption and cryptography are enabling us to have a secure conversation. To protect privacy and communicate in an undetectable way it is required to use some steganography technique. This is to hide messages in some other media generally called cover object. In todays digital world where images are a common means of information sharing, most of the steganography techniques use digital images as a carrier for hiding message. In this paper a LSB based technique is proposed for steganograpgy. This technique is different from standard LSB technique that along with message hidden in LSB bits a part of message also resides at other selective bits using a key. The method is developed to increase the payload capacity and make detection impossible.

  7. Multimodality Image Fusion-Guided Procedures: Technique, Accuracy, and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Abi-Jaoudeh, Nadine, E-mail: naj@mail.nih.gov [National Institutes of Health, Radiology and Imaging Sciences (United States); Kruecker, Jochen, E-mail: jochen.kruecker@philips.com [Philips Research North America (United States); Kadoury, Samuel, E-mail: samuel.kadoury@polymtl.ca [Ecole Polytechnique de Montreal, Department of Computer and Software Engineering, Institute of Biomedical Engineering (Canada); Kobeiter, Hicham, E-mail: hicham.kobeiter@gmail.com [CHU Henri Mondor, UPEC, Departments of Radiology and d' imagrie medicale (France); Venkatesan, Aradhana M., E-mail: VenkatesanA@cc.nih.gov; Levy, Elliot, E-mail: levyeb@cc.nih.gov; Wood, Bradford J., E-mail: bwood@cc.nih.gov [National Institutes of Health, Radiology and Imaging Sciences (United States)

    2012-10-15

    Personalized therapies play an increasingly critical role in cancer care: Image guidance with multimodality image fusion facilitates the targeting of specific tissue for tissue characterization and plays a role in drug discovery and optimization of tailored therapies. Positron-emission tomography (PET), magnetic resonance imaging (MRI), and contrast-enhanced computed tomography (CT) may offer additional information not otherwise available to the operator during minimally invasive image-guided procedures, such as biopsy and ablation. With use of multimodality image fusion for image-guided interventions, navigation with advanced modalities does not require the physical presence of the PET, MRI, or CT imaging system. Several commercially available methods of image-fusion and device navigation are reviewed along with an explanation of common tracking hardware and software. An overview of current clinical applications for multimodality navigation is provided.

  8. A Microwave Imaging and Enhancement Technique from Noisy Synthetic Data

    CERN Document Server

    Kundu, Anjan Kumar; Sanyal, Sugata

    2010-01-01

    An inverse iterative algorithm for microwave imaging based on moment method solution is presented here. The iterative scheme has been developed on constrained optimization technique and is certain to converge. Different mesh size for the model has been used here to overcome the Inverse Crime. The synthetic data at the receivers is contaminated with different percentage of noise. The ill-posedness of the problem is solved by Levenberg-Marquardt method. The algorithm is applied to synthetic data and the reconstructed image is then further enhanced through the Image enhancement technique

  9. Using image processing techniques on proximity probe signals in rotordynamics

    Science.gov (United States)

    Diamond, Dawie; Heyns, Stephan; Oberholster, Abrie

    2016-06-01

    This paper proposes a new approach to process proximity probe signals in rotordynamic applications. It is argued that the signal be interpreted as a one dimensional image. Existing image processing techniques can then be used to gain information about the object being measured. Some results from one application is presented. Rotor blade tip deflections can be calculated through localizing phase information in this one dimensional image. It is experimentally shown that the newly proposed method performs more accurately than standard techniques, especially where the sampling rate of the data acquisition system is inadequate by conventional standards.

  10. The Real-Time Image Processing Technique Based on DSP

    Institute of Scientific and Technical Information of China (English)

    QI Chang; CHEN Yue-hua; HUANG Tian-shu

    2005-01-01

    This paper proposes a novel real-time image processing technique based on digital singnal processor (DSP). At the aspect of wavelet transform(WT) algorithm, the technique uses algorithm of second generation wavelet transform-lifting scheme WT that has low calculation complexity property for the 2-D image data processing. Since the processing effect of lifting scheme WT for 1-D data is better than the effect of it for 2-D data obviously, this paper proposes a reformative processing method: Transform 2-D image data to 1-D data sequence by linearization method, then process the 1-D data sequence by algorithm of lifting scheme WT. The method changes the image convolution mode,which based on the cross filtering of rows and columns. At the aspect of hardware realization, the technique optimizes the program structure of DSP to exert the operation power with the in-chip memorizer of DSP. The experiment results show that the real-time image processing technique proposed in this paper can meet the real-time requirement of video-image transmitting in the video surveillance system of electric power. So the technique is a feasible and efficient DSP solution.

  11. A Blind High-Capacity Wavelet-Based Steganography Technique for Hiding Images into other Images

    Directory of Open Access Journals (Sweden)

    HAMAD, S.

    2014-05-01

    Full Text Available The flourishing field of Steganography is providing effective techniques to hide data into different types of digital media. In this paper, a novel technique is proposed to hide large amounts of image data into true colored images. The proposed method employs wavelet transforms to decompose images in a way similar to the Human Visual System (HVS for more secure and effective data hiding. The designed model can blindly extract the embedded message without the need to refer to the original cover image. Experimental results showed that the proposed method outperformed all of the existing techniques not only imperceptibility but also in terms of capacity. In fact, the proposed technique showed an outstanding performance on hiding a secret image whose size equals 100% of the cover image while maintaining excellent visual quality of the resultant stego-images.

  12. Nondestructive evaluation technique using infrared thermography and terahertz imaging

    Science.gov (United States)

    Sakagami, Takahide; Shiozawa, Daiki; Tamaki, Yoshitaka; Iwama, Tatsuya

    2016-05-01

    Nondestructive testing (NDT) techniques using pulse heating infrared thermography and terahertz (THz) imaging were developed for detecting deterioration of oil tank floor, such as blister and delamination of corrosion protection coating, or corrosion of the bottom steel plate under coating. Experimental studies were conducted to demonstrate the practicability of developed techniques. It was found that the pulse heating infrared thermography was utilized for effective screening inspection and THz-TDS imaging technique performed well for the detailed inspection of coating deterioration and steel corrosion.

  13. A Review of Image Contrast Enhancement Methods and Techniques

    Directory of Open Access Journals (Sweden)

    G. Maragatham

    2015-02-01

    Full Text Available In this study we aim to provide a survey of existing enhancement techniques with their descriptions and present a detailed analysis of them. Since most of the images while capturing are affected by weather, poor lighting and the acquiring device itself, they suffer from poor contrast. Sufficient Contrast in an image makes an object distinguishable from the other objects and the background. Contrast enhancement improves the quality of images for human observer by expanding the dynamic range of input gray level. A plethora enhancement techniques have though emerged, none of them deem to be a universal one, thus becoming selective in application. In such a scenario, it has become imperative to provide a comprehensive survey of these contrast enhancement techniques used in digital image processing.

  14. Peplography: an image restoration technique through scattering media

    Science.gov (United States)

    Cho, Myungjin; Cho, Ki-Ok; Kim, Youngjun

    2016-06-01

    In this paper, we propose an image restoration technique through scattering media. Under natural light an imaging through scattering media is a big challenge in many applications. To overcome this challenge, many methods have been reported such as non-invasive imaging, ghost imaging, and wavefront shaping. However, their results have not been sufficient for observers. In this paper, we estimate the scattering media by statistical estimation such as maximum likelihood estimation. By removing this estimated scattering media from the original image, we can obtain the image with only ballistic photons. Then, the ballistic photons can be detected by photon counting imaging concept. In addition, since each basic color channel has its own wavelength, color photon counting process can be implemented. To enhance the visual quality of the result image, a passive three-dimensional (3D) imaging technique such as integral imaging is used. To prove our method and show the better performance, we carried out optical experiments and calculate mean square error (MSE).

  15. Interferometric and nonlinear-optical spectral-imaging techniques for outer space and live cells

    Science.gov (United States)

    Itoh, Kazuyoshi

    2015-12-01

    Multidimensional signals such as the spectral images allow us to have deeper insights into the natures of objects. In this paper the spectral imaging techniques that are based on optical interferometry and nonlinear optics are presented. The interferometric imaging technique is based on the unified theory of Van Cittert-Zernike and Wiener-Khintchine theorems and allows us to retrieve a spectral image of an object in the far zone from the 3D spatial coherence function. The retrieval principle is explained using a very simple object. The promising applications to space interferometers for astronomy that are currently in progress will also be briefly touched on. An interesting extension of interferometric spectral imaging is a 3D and spectral imaging technique that records 4D information of objects where the 3D and spectral information is retrieved from the cross-spectral density function of optical field. The 3D imaging is realized via the numerical inverse propagation of the cross-spectral density. A few techniques suggested recently are introduced. The nonlinear optical technique that utilizes stimulated Raman scattering (SRS) for spectral imaging of biomedical targets is presented lastly. The strong signals of SRS permit us to get vibrational information of molecules in the live cell or tissue in real time. The vibrational information of unstained or unlabeled molecules is crucial especially for medical applications. The 3D information due to the optical nonlinearity is also the attractive feature of SRS spectral microscopy.

  16. Comparative performance of image fusion methodologies in eddy current testing

    Directory of Open Access Journals (Sweden)

    S. Thirunavukkarasu

    2012-12-01

    Full Text Available Image fusion methodologies have been studied for improving the detectability of eddy current Nondestructive Testing (NDT. Pixel level image fusion has been performed on C-scan eddy current images of a sub-surface defect at two different frequencies. Multi-resolution analysis based Laplacian pyramid and wavelet fusion methodologies, statistical inference based Bayesian fusion and Principal Component Analysis (PCA based fusion methodologies have been studied towards improving the detectability of defects. The performance of the fusion methodologies has been compared using image metrics such as SNR and entropy. Bayesian based fusion methodology has shown better performance as compared to other methodologies with 33.75 dB improvement in the SNR and an improvement of 3.22 in the entropy.

  17. Digital signal processing techniques and applications in radar image processing

    CERN Document Server

    Wang, Bu-Chin

    2008-01-01

    A self-contained approach to DSP techniques and applications in radar imagingThe processing of radar images, in general, consists of three major fields: Digital Signal Processing (DSP); antenna and radar operation; and algorithms used to process the radar images. This book brings together material from these different areas to allow readers to gain a thorough understanding of how radar images are processed.The book is divided into three main parts and covers:* DSP principles and signal characteristics in both analog and digital domains, advanced signal sampling, and

  18. Current status of paediatric post-mortem imaging: an ESPR questionnaire-based survey

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Owen J. [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Radiology, London (United Kingdom); University College London, Institute of Child Health, London (United Kingdom); Rijn, Rick R. van [Academic Medical Centre, Department of Radiology, Amsterdam (Netherlands); Sebire, Neil J. [Great Ormond Street Hospital for Children, Department of Pathology, London (United Kingdom); University College London, Institute of Child Health, London (United Kingdom)

    2014-03-15

    The use of post-mortem imaging, including skeletal radiography, CT and MRI, is increasing, providing a minimally invasive alternative to conventional autopsy techniques. The development of clinical guidelines and national standards is being encouraged, particularly for cross-sectional techniques. To outline the current practice of post-mortem imaging amongst members of the European Society of Paediatric Radiology (ESPR). We e-mailed an online questionnaire of current post-mortem service provisions to members of the ESPR in January 2013. The survey included direct questions about what services were offered, the population imaged, current techniques used, imaging protocols, reporting experience and intended future involvement. Seventy-one percent (47/66) of centres from which surveys were returned reported performing some form of post-mortem imaging in children, of which 81 % perform radiographs, 51% CT and 38% MRI. Eighty-seven percent of the imaging is performed within the radiology or imaging departments, usually by radiographers (75%), and 89% is reported by radiologists, of which 64% is reported by paediatric radiologists. Overall, 72% of positive respondents have a standardised protocol for radiographs, but only 32% have such a protocol for CT and 27% for MRI. Sixty-one percent of respondents wrote that this is an important area that needs to be developed. Overall, the majority of centres provide some post-mortem imaging service, most of which is performed within an imaging department and reported by a paediatric radiologist. However, the populations imaged as well as the details of the services offered are highly variable among institutions and lack standardisation. We have identified people who would be interested in taking this work forwards. (orig.)

  19. MALDI imaging mass spectrometry: statistical data analysis and current computational challenges

    Directory of Open Access Journals (Sweden)

    Alexandrov Theodore

    2012-11-01

    Full Text Available Abstract Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF imaging mass spectrometry, also called MALDI-imaging, is a label-free bioanalytical technique used for spatially-resolved chemical analysis of a sample. Usually, MALDI-imaging is exploited for analysis of a specially prepared tissue section thaw mounted onto glass slide. A tremendous development of the MALDI-imaging technique has been observed during the last decade. Currently, it is one of the most promising innovative measurement techniques in biochemistry and a powerful and versatile tool for spatially-resolved chemical analysis of diverse sample types ranging from biological and plant tissues to bio and polymer thin films. In this paper, we outline computational methods for analyzing MALDI-imaging data with the emphasis on multivariate statistical methods, discuss their pros and cons, and give recommendations on their application. The methods of unsupervised data mining as well as supervised classification methods for biomarker discovery are elucidated. We also present a high-throughput computational pipeline for interpretation of MALDI-imaging data using spatial segmentation. Finally, we discuss current challenges associated with the statistical analysis of MALDI-imaging data.

  20. Current trends in medical image registration and fusion

    Directory of Open Access Journals (Sweden)

    Fatma El-Zahraa Ahmed El-Gamal

    2016-03-01

    Full Text Available Recently, medical image registration and fusion processes are considered as a valuable assistant for the medical experts. The role of these processes arises from their ability to help the experts in the diagnosis, following up the diseases’ evolution, and deciding the necessary therapies regarding the patient’s condition. Therefore, the aim of this paper is to focus on medical image registration as well as medical image fusion. In addition, the paper presents a description of the common diagnostic images along with the main characteristics of each of them. The paper also illustrates most well-known toolkits that have been developed to help the working with the registration and fusion processes. Finally, the paper presents the current challenges associated with working with medical image registration and fusion through illustrating the recent diseases/disorders that were addressed through such an analyzing process.

  1. [Novel endoscopic techniques to image the upper gastrointestinal tract].

    Science.gov (United States)

    Quénéhervé, Lucille; Neunlist, Michel; Bruley des Varannes, Stanislas; Tearney, Guillermo; Coron, Emmanuel

    2015-01-01

    Novel endoscopic techniques for the analysis of the digestive wall have recently been developed to allow investigating digestive diseases beyond standard "white-light" macroscopic imaging of the mucosal surface. Among innovative techniques under clinical evaluation, confocal endomicroscopy and optical frequency domain imaging (OFDI) are the most promising. Indeed, these techniques allow performing in vivo microscopy with different levels in terms of depths and magnification, as well as functional assessment of structures. Some of these techniques, such as capsule-based OFDI, are also less invasive than traditional endoscopy and might help screening large groups of patients for specific disorders, for instance oesophageal precancerous diseases. In this review, we will focus on the results obtained with these techniques in precancerous, inflammatory and neuromuscular disorders.

  2. Technique of Embedding Depth Maps into 2D Images

    Institute of Scientific and Technical Information of China (English)

    Kazutake Uehira; Hiroshi Unno; Youichi Takashima

    2014-01-01

    This paper proposes a new technique that is used to embed depth maps into corresponding 2-dimensional (2D) images. Since a 2D image and its depth map are integrated into one type of image format, they can be treated as if they were one 2D image. Thereby, it can reduce the amount of data in 3D images by half and simplify the processes for sending them through networks because the synchronization between images for the left and right eyes becomes unnecessary. We embed depth maps in the quantized discrete cosine transform (DCT) data of 2D images. The key to this technique is whether the depth maps could be embedded into 2D images without perceivably deteriorating their quality. We try to reduce their deterioration by compressing the depth map data by using the differences from the next pixel to the left. We assume that there is only one non-zero pixel at most on one horizontal line in the DCT block because the depth map values change abruptly. We conduct an experiment to evaluate the quality of the 2D images embedded with depth maps and find that satisfactory quality could be achieved.

  3. A Document Imaging Technique for Implementing Electronic Loan Approval Process

    Directory of Open Access Journals (Sweden)

    J. Manikandan

    2015-04-01

    Full Text Available The image processing is one of the leading technologies of computer applications. Image processing is a type of signal processing, the input for image processor is an image or video frame and the output will be an image or subset of image [1]. Computer graphics and computer vision process uses an image processing techniques. Image processing systems are used in various environments like medical fields, computer-aided design (CAD, research fields, crime investigation fields and military fields. In this paper, we proposed a document image processing technique, for establishing electronic loan approval process (E-LAP [2]. Loan approval process has been tedious process, the E-LAP system attempts to reduce the complexity of loan approval process. Customers have to login to fill the loan application form online with all details and submit the form. The loan department then processes the submitted form and then sends an acknowledgement mail via the E-LAP to the requested customer with the details about list of documents required for the loan approval process [3]. The approaching customer can upload the scanned copies of all required documents. All this interaction between customer and bank take place using an E-LAP system.

  4. Operational prediction of rip currents using numerical model and nearshore bathymetry from video images

    Science.gov (United States)

    Sembiring, L.; Van Ormondt, M.; Van Dongeren, A. R.; Roelvink, J. A.

    2017-07-01

    Rip currents are one of the most dangerous coastal hazards for swimmers. In order to minimize the risk, a coastal operational-process based-model system can be utilized in order to provide forecast of nearshore waves and currents that may endanger beach goers. In this paper, an operational model for rip current prediction by utilizing nearshore bathymetry obtained from video image technique is demonstrated. For the nearshore scale model, XBeach1 is used with which tidal currents, wave induced currents (including the effect of the wave groups) can be simulated simultaneously. Up-to-date bathymetry will be obtained using video images technique, cBathy 2. The system will be tested for the Egmond aan Zee beach, located in the northern part of the Dutch coastline. This paper will test the applicability of bathymetry obtained from video technique to be used as input for the numerical modelling system by comparing simulation results using surveyed bathymetry and model results using video bathymetry. Results show that the video technique is able to produce bathymetry converging towards the ground truth observations. This bathymetry validation will be followed by an example of operational forecasting type of simulation on predicting rip currents. Rip currents flow fields simulated over measured and modeled bathymetries are compared in order to assess the performance of the proposed forecast system.

  5. Pattern recognition software and techniques for biological image analysis.

    Directory of Open Access Journals (Sweden)

    Lior Shamir

    Full Text Available The increasing prevalence of automated image acquisition systems is enabling new types of microscopy experiments that generate large image datasets. However, there is a perceived lack of robust image analysis systems required to process these diverse datasets. Most automated image analysis systems are tailored for specific types of microscopy, contrast methods, probes, and even cell types. This imposes significant constraints on experimental design, limiting their application to the narrow set of imaging methods for which they were designed. One of the approaches to address these limitations is pattern recognition, which was originally developed for remote sensing, and is increasingly being applied to the biology domain. This approach relies on training a computer to recognize patterns in images rather than developing algorithms or tuning parameters for specific image processing tasks. The generality of this approach promises to enable data mining in extensive image repositories, and provide objective and quantitative imaging assays for routine use. Here, we provide a brief overview of the technologies behind pattern recognition and its use in computer vision for biological and biomedical imaging. We list available software tools that can be used by biologists and suggest practical experimental considerations to make the best use of pattern recognition techniques for imaging assays.

  6. Pattern recognition software and techniques for biological image analysis.

    Science.gov (United States)

    Shamir, Lior; Delaney, John D; Orlov, Nikita; Eckley, D Mark; Goldberg, Ilya G

    2010-11-24

    The increasing prevalence of automated image acquisition systems is enabling new types of microscopy experiments that generate large image datasets. However, there is a perceived lack of robust image analysis systems required to process these diverse datasets. Most automated image analysis systems are tailored for specific types of microscopy, contrast methods, probes, and even cell types. This imposes significant constraints on experimental design, limiting their application to the narrow set of imaging methods for which they were designed. One of the approaches to address these limitations is pattern recognition, which was originally developed for remote sensing, and is increasingly being applied to the biology domain. This approach relies on training a computer to recognize patterns in images rather than developing algorithms or tuning parameters for specific image processing tasks. The generality of this approach promises to enable data mining in extensive image repositories, and provide objective and quantitative imaging assays for routine use. Here, we provide a brief overview of the technologies behind pattern recognition and its use in computer vision for biological and biomedical imaging. We list available software tools that can be used by biologists and suggest practical experimental considerations to make the best use of pattern recognition techniques for imaging assays.

  7. IMAGE SEGMENTATION BASED ON MARKOV RANDOM FIELD AND WATERSHED TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    纳瑟; 刘重庆

    2002-01-01

    This paper presented a method that incorporates Markov Random Field(MRF), watershed segmentation and merging techniques for performing image segmentation and edge detection tasks. MRF is used to obtain an initial estimate of x regions in the image under process where in MRF model, gray level x, at pixel location i, in an image X, depends on the gray levels of neighboring pixels. The process needs an initial segmented result. An initial segmentation is got based on K-means clustering technique and the minimum distance, then the region process in modeled by MRF to obtain an image contains different intensity regions. Starting from this we calculate the gradient values of that image and then employ a watershed technique. When using MRF method it obtains an image that has different intensity regions and has all the edge and region information, then it improves the segmentation result by superimpose closed and an accurate boundary of each region using watershed algorithm. After all pixels of the segmented regions have been processed, a map of primitive region with edges is generated. Finally, a merge process based on averaged mean values is employed. The final segmentation and edge detection result is one closed boundary per actual region in the image.

  8. Video multiple watermarking technique based on image interlacing using DWT.

    Science.gov (United States)

    Ibrahim, Mohamed M; Abdel Kader, Neamat S; Zorkany, M

    2014-01-01

    Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT) is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video) are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

  9. Segmentation of Color Images Based on Different Segmentation Techniques

    Directory of Open Access Journals (Sweden)

    Purnashti Bhosale

    2013-03-01

    Full Text Available In this paper, we propose an Color image segmentation algorithm based on different segmentation techniques. We recognize the background objects such as the sky, ground, and trees etc based on the color and texture information using various methods of segmentation. The study of segmentation techniques by using different threshold methods such as global and local techniques and they are compared with one another so as to choose the best technique for threshold segmentation. Further segmentation is done by using clustering method and Graph cut method to improve the results of segmentation.

  10. Reconstructing flaw image using dataset of full matrix capture technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Hun; Kim, Yong Sik; Lee, Jeong Seok [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2017-02-15

    A conventional phased array ultrasonic system offers the ability to steer an ultrasonic beam by applying independent time delays of individual elements in the array and produce an ultrasonic image. In contrast, full matrix capture (FMC) is a data acquisition process that collects a complete matrix of A-scans from every possible independent transmit-receive combination in a phased array transducer and makes it possible to reconstruct various images that cannot be produced by conventional phased array with the post processing as well as images equivalent to a conventional phased array image. In this paper, a basic algorithm based on the LLL mode total focusing method (TFM) that can image crack type flaws is described. And this technique was applied to reconstruct flaw images from the FMC dataset obtained from the experiments and ultrasonic simulation.

  11. Oncologic image compression using both wavelet and masking techniques.

    Science.gov (United States)

    Yin, F F; Gao, Q

    1997-12-01

    A new algorithm has been developed to compress oncologic images using both wavelet transform and field masking methods. A compactly supported wavelet transform is used to decompose the original image into high- and low-frequency subband images. The region-of-interest (ROI) inside an image, such as an irradiated field in an electronic portal image, is identified using an image segmentation technique and is then used to generate a mask. The wavelet transform coefficients outside the mask region are then ignored so that these coefficients can be efficiently coded to minimize the image redundancy. In this study, an adaptive uniform scalar quantization method and Huffman coding with a fixed code book are employed in subsequent compression procedures. Three types of typical oncologic images are tested for compression using this new algorithm: CT, MRI, and electronic portal images with 256 x 256 matrix size and 8-bit gray levels. Peak signal-to-noise ratio (PSNR) is used to evaluate the quality of reconstructed image. Effects of masking and image quality on compression ratio are illustrated. Compression ratios obtained using wavelet transform with and without masking for the same PSNR are compared for all types of images. The addition of masking shows an increase of compression ratio by a factor of greater than 1.5. The effect of masking on the compression ratio depends on image type and anatomical site. A compression ratio of greater than 5 can be achieved for a lossless compression of various oncologic images with respect to the region inside the mask. Examples of reconstructed images with compression ratio greater than 50 are shown.

  12. Implementing Tumor Detection and Area Calculation in Mri Image of Human Brain Using Image Processing Techniques

    OpenAIRE

    Sunil L. Bangare; Madhura Patil

    2015-01-01

    This paper is based on the research on Human Brain Tumor which uses the MRI imaging technique to capture the image. In this proposed work Brain Tumor area is calculated to define the Stage or level of seriousness of the tumor. Image Processing techniques are used for the brain tumor area calculation and Neural Network algorithms for the tumor position calculation. Also in the further advancement the classification of the tumor based on few parameters is also expected. Proposed wor...

  13. High-Resolution MR Imaging with Strong Local "surface" Gradient Coils, and, Optimization of Spgr Techniques for Functional MR Imaging.

    Science.gov (United States)

    Jin, Haoran

    In this thesis we discuss two specific topics in magnetic resonance imaging. The first concerns the technical requirements of high resolution MR imaging. Unique local "surface" gradient coils have been designed, constructed, integrated with a whole body MR imaging system, and used to acquire MR images demonstrating higher spatial resolution in three dimensions. The novel gradient coil design generates a strong linear gradient-field in three dimensions near the planar surface of the coil assembly for high resolution MR skin imaging. The rise times of the gradient coils were measured to be less than 250 mus, allowing rapid gradient coil switching. No significant eddy current effects have been found on the images. Images of a phantom and human skin with a field of view 3 cm by 3 cm and matrix size of 512 x 384 were obtained, corresponding to an in-plane resolution of 58 by 78 mu m. The resulting images represent a significant improvement in limiting spatial resolution compared to conventional MR images. The second topic of this thesis is functional MR imaging (FMRI). Functional MR imaging is based on the concept that neural activity in the cerebral cortex causes an increase in blood flow and a decrease in capillary deoxyhemoglobin concentrations, producing a signal enhancement in T2 ^*-weighted pulse sequences. The magnetic susceptibility of blood changes the oxygenation, changing the local T2^*. Spoiled gradient echo (SPGR) techniques both theoretically and experimentally have been optimized for functional MRI of human motor cortex. Experimental measurements have been performed and compared with the theoretical optimizations of signal to noise ratios of subtracted SPGR imaging. The experimental data are in good agreement with theoretical calculations. An FMRI of motor cortex stimulation with more than 5% intensity change has been observed using optimized techniques. Post imaging processing has been employed for displaying signal changes in the functional MR imaging.

  14. Imaging of the hip and bony pelvis. Techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Davies, A.M. [Royal Orthopaedic Hospital, Birmingham (United Kingdom). MRI Centre; Johnson, K.J. [Princess of Wales Birmingham Children' s Hospital (United Kingdom); Whitehouse, R.W. (eds.) [Manchester Royal Infirmary (United Kingdom). Dept. of Clinical Radiology

    2006-07-01

    This is a comprehensive textbook on imaging of the bony pelvis and hip joint that provides a detailed description of the techniques and imaging findings relevant to this complex anatomical region. In the first part of the book, the various techniques and procedures employed for imaging the pelvis and hip are discussed in detail. The second part of the book documents the application of these techniques to the diverse clinical problems and diseases encountered. Among the many topics addressed are congenital and developmental disorders including developmental dysplasia of the hip, irritable hip and septic arthritis, Perthes' disease and avascular necrosis, slipped upper femoral epiphysis, bony and soft tissue trauma, arthritis, tumours and hip prostheses. Each chapter is written by an acknowledged expert in the field, and a wealth of illustrative material is included. This book will be of great value to musculoskeletal and general radiologists, orthopaedic surgeons and rheumatologists. (orig.)

  15. Multimodal backside imaging of a microcontroller using confocal laser scanning and optical-beam-induced current imaging

    Science.gov (United States)

    Finkeldey, Markus; Göring, Lena; Schellenberg, Falk; Brenner, Carsten; Gerhardt, Nils C.; Hofmann, Martin

    2017-02-01

    Microscopy imaging with a single technology is usually restricted to a single contrast mechanism. Multimodal imaging is a promising technique to improve the structural information that could be obtained about a device under test (DUT). Due to the different contrast mechanisms of laser scanning microscopy (LSM), confocal laser scanning microscopy (CLSM) and optical beam induced current microscopy (OBICM), a combination could improve the detection of structures in integrated circuits (ICs) and helps to reveal their layout. While OBIC imaging is sensitive to the changes between differently doped areas and to semiconductor-metal transitions, CLSM imaging is mostly sensitive to changes in absorption and reflection. In this work we present the implementation of OBIC imaging into a CLSM. We show first results using industry standard Atmel microcontrollers (MCUs) with a feature size of about 250nm as DUTs. Analyzing these types of microcontrollers helps to improve in the field of side-channel attacks to find hardware Trojans, possible spots for laser fault attacks and for reverse engineering. For the experimental results the DUT is placed on a custom circuit board that allows us to measure the current while imaging it in our in-house built stage scanning microscope using a near infrared (NIR) laser diode as light source. The DUT is thinned and polished, allowing backside imaging through the Si-substrate. We demonstrate the possibilities using this optical setup by evaluating OBIC, LSM and CLSM images above and below the threshold of the laser source.

  16. Image Classifying Registration for Gaussian & Bayesian Techniques: A Review

    Directory of Open Access Journals (Sweden)

    Rahul Godghate,

    2014-04-01

    Full Text Available A Bayesian Technique for Image Classifying Registration to perform simultaneously image registration and pixel classification. Medical image registration is critical for the fusion of complementary information about patient anatomy and physiology, for the longitudinal study of a human organ over time and the monitoring of disease development or treatment effect, for the statistical analysis of a population variation in comparison to a so-called digital atlas, for image-guided therapy, etc. A Bayesian Technique for Image Classifying Registration is well-suited to deal with image pairs that contain two classes of pixels with different inter-image intensity relationships. We will show through different experiments that the model can be applied in many different ways. For instance if the class map is known, then it can be used for template-based segmentation. If the full model is used, then it can be applied to lesion detection by image comparison. Experiments have been conducted on both real and simulated data. It show that in the presence of an extra-class, the classifying registration improves both the registration and the detection, especially when the deformations are small. The proposed model is defined using only two classes but it is straightforward to extend it to an arbitrary number of classes.

  17. A human visual based binarization technique for histological images

    Science.gov (United States)

    Shreyas, Kamath K. M.; Rajendran, Rahul; Panetta, Karen; Agaian, Sos

    2017-05-01

    In the field of vision-based systems for object detection and classification, thresholding is a key pre-processing step. Thresholding is a well-known technique for image segmentation. Segmentation of medical images, such as Computed Axial Tomography (CAT), Magnetic Resonance Imaging (MRI), X-Ray, Phase Contrast Microscopy, and Histological images, present problems like high variability in terms of the human anatomy and variation in modalities. Recent advances made in computer-aided diagnosis of histological images help facilitate detection and classification of diseases. Since most pathology diagnosis depends on the expertise and ability of the pathologist, there is clearly a need for an automated assessment system. Histological images are stained to a specific color to differentiate each component in the tissue. Segmentation and analysis of such images is problematic, as they present high variability in terms of color and cell clusters. This paper presents an adaptive thresholding technique that aims at segmenting cell structures from Haematoxylin and Eosin stained images. The thresholded result can further be used by pathologists to perform effective diagnosis. The effectiveness of the proposed method is analyzed by visually comparing the results to the state of art thresholding methods such as Otsu, Niblack, Sauvola, Bernsen, and Wolf. Computer simulations demonstrate the efficiency of the proposed method in segmenting critical information.

  18. Improving face image extraction by using deep learning technique

    Science.gov (United States)

    Xue, Zhiyun; Antani, Sameer; Long, L. R.; Demner-Fushman, Dina; Thoma, George R.

    2016-03-01

    The National Library of Medicine (NLM) has made a collection of over a 1.2 million research articles containing 3.2 million figure images searchable using the Open-iSM multimodal (text+image) search engine. Many images are visible light photographs, some of which are images containing faces ("face images"). Some of these face images are acquired in unconstrained settings, while others are studio photos. To extract the face regions in the images, we first applied one of the most widely-used face detectors, a pre-trained Viola-Jones detector implemented in Matlab and OpenCV. The Viola-Jones detector was trained for unconstrained face image detection, but the results for the NLM database included many false positives, which resulted in a very low precision. To improve this performance, we applied a deep learning technique, which reduced the number of false positives and as a result, the detection precision was improved significantly. (For example, the classification accuracy for identifying whether the face regions output by this Viola- Jones detector are true positives or not in a test set is about 96%.) By combining these two techniques (Viola-Jones and deep learning) we were able to increase the system precision considerably, while avoiding the need to manually construct a large training set by manual delineation of the face regions.

  19. The Pre-Processing of Images Technique for the Materia

    Directory of Open Access Journals (Sweden)

    Yevgeniy P. Putyatin

    2016-08-01

    Full Text Available The image processing analysis is one of the most powerful tool in various research fields, especially in material / polymer science. Therefore in the present article an attempt has been made for study of pre-processing of images technique of the material samples during the images taken out by Scanning Electron Microscope (SEM. First we prepared the material samples with coir fibre (natural and its polymer composite after that the image analysis has been performed by SEM technique and later on the said studies have been conducted. The results presented here were found satisfactory and also are in good agreement with our earlier work and some other worker in the same field.

  20. Stellar Family Portrait Takes Imaging Technique to New Extremes

    Science.gov (United States)

    2009-12-01

    The young star cluster Trumpler 14 is revealed in another stunning ESO image. The amount of exquisite detail seen in this portrait, which beautifully reveals the life of a large family of stars, is due to the Multi-conjugate Adaptive optics Demonstrator (MAD) on ESO's Very Large Telescope. Never before has such a large patch of sky been imaged using adaptive optics [1], a technique by which astronomers are able to remove most of the atmosphere's blurring effects. Noted for harbouring Eta Carinae - one of the wildest and most massive stars in our galaxy - the impressive Carina Nebula also houses a handful of massive clusters of young stars. The youngest of these stellar families is the Trumpler 14 star cluster, which is less than one million years old - a blink of an eye in the Universe's history. This large open cluster is located some 8000 light-years away towards the constellation of Carina (the Keel). A team of astronomers, led by Hugues Sana, acquired astounding images of the central part of Trumpler 14 using the Multi-conjugate Adaptive optics Demonstrator (MAD, [2]) mounted on ESO's Very Large Telescope (VLT). Thanks to MAD, astronomers were able to remove most of the blurring effects of the atmosphere and thus obtain very sharp images. MAD performs this correction over a much larger patch of the sky than any other current adaptive optics instrument, allowing astronomers to make wider, crystal-clear images. Thanks to the high quality of the MAD images, the team of astronomers could obtain a very nice family portrait. They found that Trumpler 14 is not only the youngest - with a refined, newly estimated age of just 500 000 years - but also one of the most populous star clusters within the nebula. The astronomers counted about 2000 stars in their image, spanning the whole range from less than one tenth up to a factor of several tens of times the mass of our own Sun. And this in a region which is only about six light-years across, that is, less than twice the

  1. Modern imaging techniques during therapy in patients with multiple myeloma

    Energy Technology Data Exchange (ETDEWEB)

    Horger, M; Claussen, CD; Lichy, M (Dept. of Diagnostic and Interventional Radiology, Eberhard-Karls-Univ. (Germany)), email: marius.horger@med.uni-tuebingen.de; Weisel, K (Dept. of Internal Medicine II, Hematology and Oncology, Eberhard-Karls-Univ. (Germany)); Bares, R (Dept. of Nuclear Medicine, Eberhard-Karls-Univ. (Germany)); Ernemann, U; Fenchel, M (Dept. of Diagnostic and Interventional Neuroadiology, Eberhard-Karls-Univ., Tuebingen (Germany))

    2011-10-15

    Imaging modalities used in the diagnosis of multiple myeloma have evolved and most of them are also suitable for either early or mid-term monitoring of response to novel antimyeloma therapy. This pictorial essay focuses on modern imaging techniques for diagnosis and follow-up of patients with multiple myeloma in order to highlight their individual strengths and limitations. Also, the impact of recently established modern pharmaceutical therapy, like anti-angiogenic medication, on the tumor is addressed

  2. A novel image inpainting technique based on median diffusion

    Indian Academy of Sciences (India)

    Rajkumar L Biradar; Vinayadatt V Kohir

    2013-08-01

    Image inpainting is the technique of filling-in the missing regions and removing unwanted objects from an image by diffusing the pixel information from the neighbourhood pixels. Image inpainting techniques are in use over a long time for various applications like removal of scratches, restoring damaged/missing portions or removal of objects from the images, etc. In this study, we present a simple, yet unexplored (digital) image inpainting technique using median filter, one of the most popular nonlinear (order statistics) filters. The median is maximum likelihood estimate of location for the Laplacian distribution. Hence, the proposed algorithm diffuses median value of pixels from the exterior area into the inner area to be inpainted. The median filter preserves the edge which is an important property needed to inpaint edges. This technique is stable. Experimental results show remarkable improvements and works for homogeneous as well as heterogeneous background. PSNR (quantitative assessment) is used to compare inpainting results.

  3. Molecular Imaging of Tumors Using a Quantitative T1 Mapping Technique via Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Kelsey Herrmann

    2015-07-01

    Full Text Available Magnetic resonance imaging (MRI of glioblastoma multiforme (GBM with molecular imaging agents would allow for the specific localization of brain tumors. Prior studies using T1-weighted MR imaging demonstrated that the SBK2-Tris-(Gd-DOTA3 molecular imaging agent labeled heterotopic xenograft models of brain tumors more intensely than non-specific contrast agents using conventional T1-weighted imaging techniques. In this study, we used a dynamic quantitative T1 mapping strategy to more objectively compare intra-tumoral retention of the SBK2-Tris-(Gd-DOTA3 agent over time in comparison to non-targeted control agents. Our results demonstrate that the targeted SBK2-Tris-(Gd-DOTA3 agent, a scrambled-Tris-(Gd-DOTA3 control agent, and the non-specific clinical contrast agent Optimark™ all enhanced flank tumors of human glioma cells with similar maximal changes on T1 mapping. However, the retention of the agents differs. The non-specific agents show significant recovery within 20 min by an increase in T1 while the specific agent SBK2-Tris-(Gd-DOTA3 is retained in the tumors and shows little recovery over 60 min. The retention effect is demonstrated by percent change in T1 values and slope calculations as well as by calculations of gadolinium concentration in tumor compared to muscle. Quantitative T1 mapping demonstrates the superior binding and retention in tumors of the SBK2-Tris-(Gd-DOTA3 agent over time compared to the non-specific contrast agent currently in clinical use.

  4. Beyond the current noise limit in imaging through turbulent medium

    CERN Document Server

    Popowicz, A; Pollo, A; Smolka, B

    2015-01-01

    Shift-and-add is an approach employed to mitigate the phenomenon of resolution degradation in images acquired through a turbulent medium. Using this technique, a large number of consecutive short exposures is registered below the coherence time of the atmosphere or other blurring medium. The acquired images are shifted to the position of the brightest speckle and stacked together to obtain high-resolution and high signal-to-noise frame. In this paper we present a highly efficient method for determination of frames shifts, even if in a single frame the object cannot be distinguished from the background noise. The technique utilizes our custom genetic algorithm, which iteratively evolves a set of image shifts. We used the maximal energy of stacked images as an objective function for shifts estimation and validate the efficiency of the method on simulated and real images of simple and complex sources. Obtained results confirmed, that our proposed method allows for the recovery of spatial distribution of objects ...

  5. A novel data processing technique for image reconstruction of penumbral imaging

    Science.gov (United States)

    Xie, Hongwei; Li, Hongyun; Xu, Zeping; Song, Guzhou; Zhang, Faqiang; Zhou, Lin

    2011-06-01

    CT image reconstruction technique was applied to the data processing of the penumbral imaging. Compared with other traditional processing techniques for penumbral coded pinhole image such as Wiener, Lucy-Richardson and blind technique, this approach is brand new. In this method, the coded aperture processing method was used for the first time independent to the point spread function of the image diagnostic system. In this way, the technical obstacles was overcome in the traditional coded pinhole image processing caused by the uncertainty of point spread function of the image diagnostic system. Then based on the theoretical study, the simulation of penumbral imaging and image reconstruction was carried out to provide fairly good results. While in the visible light experiment, the point source of light was used to irradiate a 5mm×5mm object after diffuse scattering and volume scattering. The penumbral imaging was made with aperture size of ~20mm. Finally, the CT image reconstruction technique was used for image reconstruction to provide a fairly good reconstruction result.

  6. A Range-Shift Technique for TOF Range Image Sensors

    Science.gov (United States)

    Sawada, Tomonari; Ito, Kana; Nakayama, Masakatsu; Kawahito, Shoji

    In Time-of-Flight (TOF) range image sensors using periodical pulsed light, there is a trade-off between the maximum range and range resolution. This paper proposes a range-shift technique for improving range resolution of the TOF range image sensor without sacrificing the measurement range. The range-shift operation uses a TOF range imaging pixel with periodical charge draining structure and several time-shifted short pulses. The use of the short pulse can improve the range resolution. The range image using the range-shift technique is synthesized with several sub-frames, each acquires one of the shifted range images. The use of the small duty-ratio pulse leads to reducing the effect of ambient light and improving the range resolution. The range-shift technique is tested with an implemented TOF range image sensor and it is found that the range resolution is improved to 2cm using a 10ns light pulse and 7 overlapped shifted ranges for the measurement range of 0.5m to 4.0m.

  7. A statistical watermark detection technique without using original images for resolving rightful ownerships of digital images.

    Science.gov (United States)

    Zeng, W; Liu, B

    1999-01-01

    Digital watermarking has been proposed as the means for copyright protection of multimedia data. Many of existing watermarking schemes focused on the robust means to mark an image invisibly without really addressing the ends of these schemes. This paper first discusses some scenarios in which many current watermarking schemes fail to resolve the rightful ownership of an image. The key problems are then identified, and some crucial requirements for a valid invisible watermark detection are discussed. In particular, we show that, for the particular application of resolving rightful ownership using invisible watermarks, it might be crucial to require that the original image not be directly involved in the watermark detection process. A general framework for validly detecting the invisible watermarks is then proposed. Some requirements on the claimed signature/watermarks to be used for detection are discussed to prevent the existence of any counterfeit scheme. The optimal detection strategy within the framework is derived. We show the effectiveness of this technique based on some visual-model-based watermark encoding schemes.

  8. A novel scheme for binarization of vehicle images using hierarchical histogram equalization technique

    CERN Document Server

    Saha, Satadal; Nasipuri, Mita; Basu, Dipak Kumar

    2010-01-01

    Automatic License Plate Recognition system is a challenging area of research now-a-days and binarization is an integral and most important part of it. In case of a real life scenario, most of existing methods fail to properly binarize the image of a vehicle in a congested road, captured through a CCD camera. In the current work we have applied histogram equalization technique over the complete image and also over different hierarchy of image partitioning. A novel scheme is formulated for giving the membership value to each pixel for each hierarchy of histogram equalization. Then the image is binarized depending on the net membership value of each pixel. The technique is exhaustively evaluated on the vehicle image dataset as well as the license plate dataset, giving satisfactory performances.

  9. Current Status of Gil-Vernet Trigonoplasty Technique

    Directory of Open Access Journals (Sweden)

    Nasser Simforoosh

    2008-01-01

    Full Text Available Significant controversy exists regarding vesicoureteral reflux (VUR management, due to lack of sufficient prospective studies. The rationale for surgical management is that VUR can cause recurrent episodes of pyelonephritis and long-term renal damage. Several surgical techniques have been introduced during the past decades. Open anti-reflux operations have high success rate, exceeding 95%, and long durability. The goal of this article is to review the Gil-Vernet trigonoplasty technique, which is a simple and highly successful technique but has not gained the attention it deserves. The mainstay of this technique is approximation of medial aspects of ureteral orifices to midline by one mattress suture. A unique advantage of Gil-Vernet trigonoplasty is its bilateral nature, which results in prevention from contralateral new reflux. Regarding not altering the normal course of the ureter in Gil-Vernet procedure, later catheterization of and retrograde access to the ureter can be performed normally. There is no report of ureterovesical junction obstruction following Gil-Vernet procedure. Gil-Vernet trigonoplasty can be performed without inserting a bladder catheter and drain on an outpatient setting. Several exclusive advantages of Gil-Vernet trigonoplasty make it necessary to reconsider the technique role in VUR management.

  10. SRG POSITION SENSORLESS TECHNIQUE WITH CURRENT CHOPPING MODE

    Institute of Scientific and Technical Information of China (English)

    ZhuXuezhong; LiuDiji; GuiXiaojie; LiuChuang

    2002-01-01

    A onvel current chopping strategy for switched reluc-tance generator(SRG)-a full conducted current chopping(FCCC)scheme is presented,According to characteristics lf phase current wave of SRG generating operation,it can be generated under sensorless condition without an addi-tional circuit or a position signal algorithm.Simulational results show the feasibility of this scheme.Experimental results of a 6kW6/4configuration SRG show its simplic-ity and high reliability with little decrease in efficiency.Soit will be widely used.

  11. A picture is worth a thousand words : content-based image retrieval techniques

    NARCIS (Netherlands)

    Thomée, Bart

    2010-01-01

    In my dissertation I investigate techniques for improving the state of the art in content-based image retrieval. To place my work into context, I highlight the current trends and challenges in my field by analyzing over 200 recent articles. Next, I propose a novel paradigm called ‘artificial imagina

  12. Modulated scattering technique in the terahertz domain enabled by current actuated vanadium dioxide switches

    Science.gov (United States)

    Vitale, W. A.; Tamagnone, M.; Émond, N.; Le Drogoff, B.; Capdevila, S.; Skrivervik, A.; Chaker, M.; Mosig, J. R.; Ionescu, A. M.

    2017-02-01

    The modulated scattering technique is based on the use of reconfigurable electromagnetic scatterers, structures able to scatter and modulate an impinging electromagnetic field in function of a control signal. The modulated scattering technique is used in a wide range of frequencies up to millimeter waves for various applications, such as field mapping of circuits or antennas, radio-frequency identification devices and imaging applications. However, its implementation in the terahertz domain remains challenging. Here, we describe the design and experimental demonstration of the modulated scattering technique at terahertz frequencies. We characterize a modulated scatterer consisting in a bowtie antenna loaded with a vanadium dioxide switch, actuated using a continuous current. The modulated scatterer behavior is demonstrated using a time domain terahertz spectroscopy setup and shows significant signal strength well above 0.5 THz, which makes this device a promising candidate for the development of fast and energy-efficient THz communication devices and imaging systems. Moreover, our experiments allowed us to verify the operation of a single micro-meter sized VO2 switch at terahertz frequencies, thanks to the coupling provided by the antenna.

  13. Image blending techniques and their application in underwater mosaicing

    CERN Document Server

    Prados, Ricard; Neumann, László

    2014-01-01

    This work proposes strategies and solutions to tackle the problem of building photo-mosaics of very large underwater optical surveys, presenting contributions to the image preprocessing, enhancing and blending steps, and resulting in an improved visual quality of the final photo-mosaic. The text opens with a comprehensive review of mosaicing and blending techniques, before proposing an approach for large scale underwater image mosaicing and blending. In the image preprocessing step, a depth dependent illumination compensation function is used to solve the non-uniform illumination appearance du

  14. Imaging techniques for elements and element species in plant science.

    Science.gov (United States)

    Wu, Bei; Becker, J Sabine

    2012-05-01

    Revealing the uptake, transport, localization and speciation of both essential and toxic elements in plants is important for understanding plant homeostasis and metabolism, subsequently, providing information for food and nutrient studies, agriculture activities, as well as environmental research. In the last decade, emerging techniques for elemental imaging and speciation analysis allowed us to obtain increasing knowledge of elemental distribution and availabilities in plants. Chemical imaging techniques include mass spectrometric methods such as secondary ionization mass spectrometry (SIMS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and synchrotron-based techniques such as X-ray fluorescence spectroscopy (SRXRF), and so forth. On the other hand, X-ray absorption spectroscopy (XAS) based on synchrotron radiation is capable of in situ investigation of local atomic structure around the central element of interest. This technique can also be operated in tandem with SRXRF to image each element species of interest within plant tissue. In this review, the principles and state-of-the-art of these techniques regarding sample preparation, advantages and limitations, and improvement of sensitivity and spatial resolution are discussed. New results with respect to elemental distribution and speciation in plants revealed by these techniques are presented.

  15. An Efficient Watermarking Technique for the Protection of Fingerprint Images

    Directory of Open Access Journals (Sweden)

    Khelifi F

    2008-01-01

    Full Text Available This paper describes an efficient watermarking technique for use to protect fingerprint images. The rationale is to embed the watermarks into the ridges area of the fingerprint images so that the technique is inherently robust, yields imperceptible watermarks, and resists well against cropping and/or segmentation attacks. The proposed technique improves the performance of optimum multibit watermark decoding, based on the maximum likelihood scheme and the statistical properties of the host data. The technique has been applied successfully on the well-known transform domains: discrete cosine transform (DCT and discrete wavelet transform (DWT. The statistical properties of the coefficients from the two transforms are modeled by a generalized Gaussian model, widely adopted in the literature. The results obtained are very attractive and clearly show significant improvements when compared to the conventional technique, which operates on the whole image. Also, the results suggest that the segmentation (cropping attack does not affect the performance of the proposed technique, which also provides more robustness against other common attacks.

  16. Image analysis techniques for the study of turbulent flows

    Directory of Open Access Journals (Sweden)

    Ferrari Simone

    2017-01-01

    Full Text Available In this paper, a brief review of Digital Image Analysis techniques employed in Fluid Mechanics for the study of turbulent flows is given. Particularly the focus is on the techniques developed by the research teams the Author worked in, that can be considered relatively “low cost” techniques. Digital Image Analysis techniques have the advantage, when compared to the traditional techniques employing physical point probes, to be non-intrusive and quasi-continuous in space, as every pixel on the camera sensor works as a single probe: consequently, they allow to obtain two-dimensional or three-dimensional fields of the measured quantity in less time. Traditionally, the disadvantages are related to the frequency of acquisition, but modern high-speed cameras are typically able to acquire at frequencies from the order of 1 KHz to the order of 1 MHz. Digital Image Analysis techniques can be employed to measure concentration, temperature, position, displacement, velocity, acceleration and pressure fields with similar equipment and setups, and can be consequently considered as a flexible and powerful tool for measurements on turbulent flows.

  17. Optical and Digital Microscopic Imaging Techniques and Applications in Pathology

    Directory of Open Access Journals (Sweden)

    Xiaodong Chen

    2011-01-01

    Full Text Available The conventional optical microscope has been the primary tool in assisting pathological examinations. The modern digital pathology combines the power of microscopy, electronic detection, and computerized analysis. It enables cellular-, molecular-, and genetic-imaging at high efficiency and accuracy to facilitate clinical screening and diagnosis. This paper first reviews the fundamental concepts of microscopic imaging and introduces the technical features and associated clinical applications of optical microscopes, electron microscopes, scanning tunnel microscopes, and fluorescence microscopes. The interface of microscopy with digital image acquisition methods is discussed. The recent developments and future perspectives of contemporary microscopic imaging techniques such as three-dimensional and in vivo imaging are analyzed for their clinical potentials.

  18. Remote sensing image denoising by using discrete multiwavelet transform techniques

    Science.gov (United States)

    Wang, Haihui; Wang, Jun; Zhang, Jian

    2006-01-01

    We present a new method by using GHM discrete multiwavelet transform in image denoising on this paper. The developments in wavelet theory have given rise to the wavelet thresholding method, for extracting a signal from noisy data. The method of signal denoising via wavelet thresholding was popularized. Multiwavelets have recently been introduced and they offer simultaneous orthogonality, symmetry and short support. This property makes multiwavelets more suitable for various image processing applications, especially denoising. It is based on thresholding of multiwavelet coefficients arising from the standard scalar orthogonal wavelet transform. It takes into account the covariance structure of the transform. Denoising of images via thresholding of the multiwavelet coefficients result from preprocessing and the discrete multiwavelet transform can be carried out by treating the output in this paper. The form of the threshold is carefully formulated and is the key to the excellent results obtained in the extensive numerical simulations of image denoising. We apply the multiwavelet-based to remote sensing image denoising. Multiwavelet transform technique is rather a new method, and it has a big advantage over the other techniques that it less distorts spectral characteristics of the image denoising. The experimental results show that multiwavelet based image denoising schemes outperform wavelet based method both subjectively and objectively.

  19. Regional environmental analysis and management: New techniques for current problems

    Science.gov (United States)

    Honea, R. B.; Paludan, C. T. N.

    1974-01-01

    Advances in data acquisition and processing procedures for regional environmental analysis are discussed. Automated and semi-automated techniques employing Earth Resources Technology Satellite data and conventional data sources are presented. Experiences are summarized. The ERTS computer compatible tapes provide a very complete and flexible record of earth resources data and represent a viable medium to enhance regional environmental analysis research.

  20. Image analysis techniques associated with automatic data base generation.

    Science.gov (United States)

    Bond, A. D.; Ramapriyan, H. K.; Atkinson, R. J.; Hodges, B. C.; Thomas, D. T.

    1973-01-01

    This paper considers some basic problems relating to automatic data base generation from imagery, the primary emphasis being on fast and efficient automatic extraction of relevant pictorial information. Among the techniques discussed are recursive implementations of some particular types of filters which are much faster than FFT implementations, a 'sequential similarity detection' technique of implementing matched filters, and sequential linear classification of multispectral imagery. Several applications of the above techniques are presented including enhancement of underwater, aerial and radiographic imagery, detection and reconstruction of particular types of features in images, automatic picture registration and classification of multiband aerial photographs to generate thematic land use maps.

  1. Line-Scan Hyperspectral Imaging Techniques for Food Safety and Quality Applications

    Directory of Open Access Journals (Sweden)

    Jianwei Qin

    2017-01-01

    Full Text Available Hyperspectral imaging technologies in the food and agricultural area have been evolving rapidly over the past 15 years owing to tremendous interest from both academic and industrial fields. Line-scan hyperspectral imaging is a major method that has been intensively researched and developed using different physical principles (e.g., reflectance, transmittance, fluorescence, Raman, and spatially resolved spectroscopy and wavelength regions (e.g., visible (VIS, near infrared (NIR, and short-wavelength infrared (SWIR. Line-scan hyperspectral imaging systems are mainly developed and used for surface inspection of food and agricultural products using area or line light sources. Some of these systems can also be configured to conduct spatially resolved spectroscopy measurements for internal or subsurface food inspection using point light sources. This paper reviews line-scan hyperspectral imaging techniques, with introduction, demonstration, and summarization of existing and emerging techniques for food and agricultural applications. The main topics include related spectroscopy techniques, line-scan measurement methods, hardware components and systems, system calibration methods, and spectral and image analysis techniques. Applications in food safety and quality are also presented to reveal current practices and future trends of line-scan hyperspectral imaging techniques.

  2. Sampling-image streak framing technique and its special streak image tube

    CERN Document Server

    Ji Lili; Lan Zhou Jun; Yang, Q L; Zhang, H; Niu, H

    2002-01-01

    We designed a special electrostatic focusing streak image tube (SIT) with large magnification, tiny temporal distortion and large dynamic range for the application of the technique of sampling-image streaking frame (SISF) for plasma diagnostics in ICF. A proof-of-principle experiment of the technique is performed with the SIT, together with a picosecond laser and image reconstruction software. Using the digital image-processing program, the result gives 16 frames with an exposure time of better than 6.3 ps.

  3. Feminist Pedagogy, Body Image, and the Dance Technique Class

    Science.gov (United States)

    Barr, Sherrie; Oliver, Wendy

    2016-01-01

    This paper investigates the evolution of feminist consciousness in dance technique class as related to body image, the myth of the perfect body, and the development of feminist pedagogy. Western concert dance forms have often been taught in a manner where imitating the teacher is primary in the learning process. In this traditional scenario,…

  4. Imaging technique for detection of internal defects of pickling cucumbers

    Science.gov (United States)

    Pickling cucumbers are susceptible to damage during harvest and postharvest handling and processing. While it is easier to detect external defects, it is difficult to detect internal defects such as bruises and hollow or split cucumbers. Hyperspectral imaging technique under transmittance mode was i...

  5. Feminist Pedagogy, Body Image, and the Dance Technique Class

    Science.gov (United States)

    Barr, Sherrie; Oliver, Wendy

    2016-01-01

    This paper investigates the evolution of feminist consciousness in dance technique class as related to body image, the myth of the perfect body, and the development of feminist pedagogy. Western concert dance forms have often been taught in a manner where imitating the teacher is primary in the learning process. In this traditional scenario,…

  6. An Image Inpainting Technique Based on the Fast Marching Method

    NARCIS (Netherlands)

    Telea, Alexandru

    2004-01-01

    Digital inpainting provides a means for reconstruction of small damaged portions of an image. Although the inpainting basics are straightforward, most inpainting techniques published in the literature are complex to understand and implement. We present here a new algorithm for digital inpainting

  7. Performance evaluation of image enhancement techniques on night vision imagery

    NARCIS (Netherlands)

    Dijk, J.; Bijl, P.; Eekeren, W.M. van

    2010-01-01

    Recently new techniques for night-vision cameras are developed. Digital image-intensifiers are becoming available on the market. Also, so-called EMCCD (electro-magnified) cameras are developed, which can also record imagery in dim conditions. In this paper we present data recorded with both types of

  8. Juvenile chronic arthritis and imaging: comparison of different techniques

    Directory of Open Access Journals (Sweden)

    C. Cervini

    2011-09-01

    Full Text Available Objective: The aim of this study was to compare imaging findings obtained with different techniques in a patient with juvenile chronic arthritis. Methods: The patient was a 12 years-old child with a 7-months history of arthritis of the first metatarsophalangeal joint of the right foot. The involved area was explored with the following imaging techniques: X-ray, technetium bone scintigraphy, magnetic resonance, gray-scale and power-Doppler ultrasonography. Results: No abnormalities were detected with conventional X-ray. Scintigraphy showed an abnormal uptake of the radionuclide in the first metatarsophalangeal joint of the right foot. Magnetic resonance without contrast revealed clearly evident features of an active process of synovitis. Ultrasonography was able to detect the presence of joint effusion, synovial proliferation, bone erosion of the first metatarsal head. Power-Doppler examination revealed evident signs of soft tissue hyperemia. Conclusions: Comparative assessment of different imaging techniques in this patient with recent-onset juvenile chronic arthritis indicates that high resolution ultrasonography provides the most detailed evaluation of the joint involvement with respect to the other imaging techniques.

  9. Secure image transform domain technique for steganographic applications

    Science.gov (United States)

    Alturki, Faisal T.; Mersereau, Russell M.

    2001-08-01

    Digital steganography is the art of secretly hiding information inside a multimedia signal in such a way that its very existence is concealed. In this paper, we present a new steganographic technique for covert communications. The technique embeds the hidden information in the transform domain after decorrelating the image samples in the spatial domain using a key. This results in a significant increase in the number of transform coefficients that can be used to transmit the hidden information, and therefore, increases the data embedding capacity. The hidden information is embedded in the transform domain after taking a block DCT of the decorrelated image. A quantization technique is used to embed the hidden data. The decoding process requires the availability of the same key that was used to decorrelate the image samples. By using quantization techniques, the hidden information can be recovered reliably. If the key is not available at the decoder it is impossible to recover the hidden information. Hence, this system is secure against removal attacks. The statistical properties of the cover and the stego image remain identical for small quantization steps. Therefore, the hidden data cannot be detected. The data embedding system is modeled as transmitting information through a Gaussian channel.

  10. Statistical Techniques for Efficient Indexing and Retrieval of Document Images

    Science.gov (United States)

    Bhardwaj, Anurag

    2010-01-01

    We have developed statistical techniques to improve the performance of document image search systems where the intermediate step of OCR based transcription is not used. Previous research in this area has largely focused on challenges pertaining to generation of small lexicons for processing handwritten documents and enhancement of poor quality…

  11. Current status of radionuclide imaging in valvular heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, C.A.; Okada, R.D.; Pohost, G.M.

    1980-12-18

    The current state-of-the-art in radionuclide imaging of valvular heart disease is based on different angiographic patterns in three left-sided valve abnormalities: pressure overload, volume overload, and inflow obstruction. In pressure overload, the left ventricle has normal dimensions or is minimally dilated the volume overload involves a left ventricular dilatation with a normal or reduced ejection fraction at rest the left ventricular function in inflow obstruction is normal, but in some cases may be depressed. Radionuclide angiography evaluates the effect of a valve abnormality on cardiac chamber and function thallium-201 imaging diagnoses regional myocardial blood flow and cell integrity and can evaluate the associated coronary artery disease.

  12. Imaging of contact acoustic nonlinearity using synthetic aperture technique.

    Science.gov (United States)

    Yun, Dongseok; Kim, Jongbeom; Jhang, Kyung-Young

    2013-09-01

    The angle beam incidence and reflection technique for the evaluation of contact acoustic nonlinearity (CAN) at solid-solid contact interfaces (e.g., closed cracks) has recently been developed to overcome the disadvantage of accessing both the inner and outer surfaces of structures for attaching pulsing and receiving transducers in the through-transmission of normal incidence technique. This paper proposes a technique for B-mode imaging of CAN based on the above reflection technique, which uses the synthetic aperture focusing technique (SAFT) and short-time Fourier transform (STFT) to visualize the distribution of the CAN-induced second harmonic magnitude as well as the nonlinear parameter. In order to verify the usefulness of the proposed method, a solid-solid contact interface was tested and the change of the contact acoustic nonlinearity according to the increasing contact pressure was visualized in images of the second harmonic magnitude and the relative nonlinear parameter. The experimental results showed good agreement with the previously developed theory identifying the dependence of the scattered second harmonics on the contact pressure. This technique can be used for the detection and improvement of the sizing accuracy of closed cracks that are difficult to detect using the conventional linear ultrasonic technique.

  13. Spine imaging after lumbar disc replacement: pitfalls and current recommendations

    Directory of Open Access Journals (Sweden)

    Sandén Bengt

    2009-07-01

    Full Text Available Abstract Background Most lumbar artificial discs are still composed of stainless steel alloys, which prevents adequate postoperative diagnostic imaging of the operated region when using magnetic resonance imaging (MRI. Thus patients with postoperative radicular symptoms or claudication after stainless steel implants often require alternative diagnostic procedures. Methods Possible complications of lumbar total disc replacement (TDR are reviewed from the available literature and imaging recommendations given with regard to implant type. Two illustrative cases are presented in figures. Results Access-related complications, infections, implant wear, loosening or fracture, polyethylene inlay dislodgement, facet joint hypertrophy, central stenosis, and ankylosis of the operated segment can be visualised both in titanium and stainless steel implants, but require different imaging modalities due to magnetic artifacts in MRI. Conclusion Alternative radiographic procedures should be considered when evaluating patients following TDR. Postoperative complications following lumbar TDR including spinal stenosis causing radiculopathy and implant loosening can be visualised by myelography and radionucleotide techniques as an adjunct to plain film radiographs. Even in the presence of massive stainless steel TDR implants lumbar radicular stenosis and implant loosening can be visualised if myelography and radionuclide techniques are applied.

  14. Bulbar urethroplasty using the dorsal approach: current techniques

    Directory of Open Access Journals (Sweden)

    Guido Barbagli

    2003-04-01

    Full Text Available INTRODUCTION: The use of flaps or grafts is mandatory in patients with longer and complex strictures. In 1995-96 we described a new dorsal onlay graft urethroplasty. Over time, our original technique was better defined and changed. Now this procedure (also named Barbagli technique has been greeted with a fair amount of enthusiasm in Europe and in the United States. SURGICAL TECHNIQUE: The patient is placed in normal lithotomy position, and a midline perineo-scrotal incision is made. The bulbar urethra is then free from the bulbo-cavernous muscles, and is dissected from the corpora cavernosa. The urethra is completely mobilized from the corpora cavernosa, it is rotated 180 degrees, and is incised along its dorsal surface. The graft (preputial skin or buccal mucosa or the flap is fixed and quilted to the tunica albuginea of the corporal bodies. The right mucosal margin of the opened urethra is sutured to the right side of the patch-graft. The urethra is rotated back into its original position. The left urethral margin is sutured to the left side of the patch graft and to the corporal bodies, and the grafted area is entirely covered by the urethral plate. The bulbo-cavernous muscles are approximated over the grafted area. A 16F silicone Foley catheter is left in place. COMMENTS: Dorsal onlay graft urethroplasty is a versatile procedure that may be combined with various substitute materials like preputial skin, buccal mucosa grafts or pedicled flaps.

  15. Automated computational aberration correction method for broadband interferometric imaging techniques.

    Science.gov (United States)

    Pande, Paritosh; Liu, Yuan-Zhi; South, Fredrick A; Boppart, Stephen A

    2016-07-15

    Numerical correction of optical aberrations provides an inexpensive and simpler alternative to the traditionally used hardware-based adaptive optics techniques. In this Letter, we present an automated computational aberration correction method for broadband interferometric imaging techniques. In the proposed method, the process of aberration correction is modeled as a filtering operation on the aberrant image using a phase filter in the Fourier domain. The phase filter is expressed as a linear combination of Zernike polynomials with unknown coefficients, which are estimated through an iterative optimization scheme based on maximizing an image sharpness metric. The method is validated on both simulated data and experimental data obtained from a tissue phantom, an ex vivo tissue sample, and an in vivo photoreceptor layer of the human retina.

  16. Secured color image watermarking technique in DWT-DCT domain

    CERN Document Server

    Gunjal, Baisa L

    2011-01-01

    The multilayer secured DWT-DCT and YIQ color space based image watermarking technique with robustness and better correlation is presented here. The security levels are increased by using multiple pn sequences, Arnold scrambling, DWT domain, DCT domain and color space conversions. Peak signal to noise ratio and Normalized correlations are used as measurement metrics. The 512x512 sized color images with different histograms are used for testing and watermark of size 64x64 is embedded in HL region of DWT and 4x4 DCT is used. 'Haar' wavelet is used for decomposition and direct flexing factor is used. We got PSNR value is 63.9988 for flexing factor k=1 for Lena image and the maximum NC 0.9781 for flexing factor k=4 in Q color space. The comparative performance in Y, I and Q color space is presented. The technique is robust for different attacks like scaling, compression, rotation etc.

  17. Molecular ultrasound imaging: current status and future directions

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, N. [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California (United States); Needles, A. [Visualsonics, Toronto (Canada); Willmann, J.K., E-mail: willmann@stanford.ed [Department of Radiology, Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California (United States)

    2010-07-15

    Targeted contrast-enhanced ultrasound (molecular ultrasound) is an emerging imaging strategy that combines ultrasound technology with novel molecularly-targeted ultrasound contrast agents for assessing biological processes at the molecular level. Molecular ultrasound contrast agents are nano- or micro-sized particles that are targeted to specific molecular markers by adding high-affinity binding ligands onto the surface of the particles. Following intravenous administration, these targeted ultrasound contrast agents accumulate at tissue sites overexpressing specific molecular markers, thereby enhancing the ultrasound imaging signal. High spatial and temporal resolution, real-time imaging, non-invasiveness, relatively low costs, lack of ionising irradiation and wide availability of ultrasound systems are advantages compared to other molecular imaging modalities. In this article we review current concepts and future directions of molecular ultrasound imaging, including different classes of molecular ultrasound contrast agents, ongoing technical developments of pre-clinical and clinical ultrasound systems, the potential of molecular ultrasound for imaging different diseases at the molecular level, and the translation of molecular ultrasound into the clinic.

  18. Detection of Cracks in Concrete Structure Using Microwave Imaging Technique

    Directory of Open Access Journals (Sweden)

    E. A. Jiya

    2016-01-01

    Full Text Available Cracks in concrete or cement based materials present a great threat to any civil structures; they are very dangerous and have caused a lot of destruction and damage. Even small cracks that look insignificant can grow and may eventually lead to severe structural failure. Besides manual inspection that is ineffective and time-consuming, several nondestructive evaluation techniques have been used for crack detection such as ultrasonic technique, vibration technique, and strain-based technique; however, some of the sensors used are either too large in size or limited in resolution. A high resolution microwave imaging technique with ultrawideband signal for crack detection in concrete structures is proposed. A combination of the delay-and-sum beamformer with full-view mounted antennas constitutes the image reconstruction algorithm. Various anomaly scenarios in cement bricks were simulated using FDTD, constructed, and measured in the lab. The reconstructed images showed a high similarity between the simulation and the experiment with a resolution of λ/14 which enables a detection of cracks as small as 5 mm in size.

  19. Biomechanical Comparison of 3 Current Ankle Syndesmosis Repair Techniques.

    Science.gov (United States)

    Clanton, Thomas O; Whitlow, Scott R; Williams, Brady T; Liechti, Daniel J; Backus, Jonathon D; Dornan, Grant J; Saroki, Adriana J; Turnbull, Travis Lee; LaPrade, Robert F

    2017-02-01

    Significant debate exists regarding optimal repair for unstable syndesmosis injuries. Techniques range from screw fixation, suture-button fixation, or a combination of the two. In this study, 3 common repairs were compared using a simulated weightbearing protocol with internal and external rotation of the foot. Twenty-four lower leg specimens with mean age 54 years (range, 38-68 years) were used for testing. Following creation of a complete syndesmotic injury (AITFL, ITFL, PITFL, interosseous membrane), specimens were repaired using 1 of 3 randomly assigned techniques: (1) one 3.5-mm syndesmotic screw, (2) 1 suture-button construct, and (3) 2 divergent suture-button constructs. Repairs were cycled for 500 cycles between 7.5 Nm of internal/external rotation torque under a constant 750 N axial compressive load in a neutral dorsiflexion position. At 0, 10, 100, and 500 cycles, torsional cyclic loading was interrupted to assess torsional resistance to rotation within a physiologic range of motion (15 degrees external rotation to 10 degrees internal rotation). Torque (Nm), rotational position (degrees), and 3-dimensional data were collected throughout the testing to characterize relative spatial relationships of the tibiofibular articulation. There were no significant differences between repair techniques in resistance to internal and external rotation with respect to the intact syndesmosis. Three-dimensional analysis revealed significant differences between repair techniques for sagittal fibular translation with external rotation of the foot. Screw fixation had the smallest magnitude of posterior sagittal translation (2.5 mm), and a single suture-button construct demonstrated the largest magnitude of posterior sagittal translation (4.6 mm). Screw fixation also allowed for significantly less anterior sagittal translation with internal rotation of the foot (0.1 mm) when compared to both 1 (2.7 mm) and 2 (2.9 mm) suture-button constructs. All repairs provided comparable

  20. Image content authentication technique based on Laplacian Pyramid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper proposes a technique of image content authentication based on the Laplacian Pyramid to verify the authenticity of image content.First,the image is decomposed into Laplacian Pyramid before the transformation.Next,the smooth and detail properties of the original image are analyzed according to the Laplacian Pyramid,and the properties are classified and encoded to get the corresponding characteristic values.Then,the signature derived from the encrypted characteristic values is embedded in the original image as a watermark.After the reception,the characteristic values of the received image are compared with the watermark drawn out from the image.The algorithm automatically identifies whether the content is tampered by means of morphologic filtration.The information of tampered location is Presented at the same time.Experimental results show that the pro posed authentication algorithm can effectively detect the event and location when the original image content is tampered.Moreover,it can tolerate some distortions produced by compression,filtration and noise degradation.

  1. Image reconstruction technique using projection data from neutron tomography system

    Directory of Open Access Journals (Sweden)

    Waleed Abd el Bar

    2015-12-01

    Full Text Available Neutron tomography is a very powerful technique for nondestructive evaluation of heavy industrial components as well as for soft hydrogenous materials enclosed in heavy metals which are usually difficult to image using X-rays. Due to the properties of the image acquisition system, the projection images are distorted by several artifacts, and these reduce the quality of the reconstruction. In order to eliminate these harmful effects the projection images should be corrected before reconstruction. This paper gives a description of a filter back projection (FBP technique, which is used for reconstruction of projected data obtained from transmission measurements by neutron tomography system We demonstrated the use of spatial Discrete Fourier Transform (DFT and the 2D Inverse DFT in the formulation of the method, and outlined the theory of reconstruction of a 2D neutron image from a sequence of 1D projections taken at different angles between 0 and π in MATLAB environment. Projections are generated by applying the Radon transform to the original image at different angles.

  2. Molecular imaging of rheumatoid arthritis: emerging markers, tools, and techniques.

    Science.gov (United States)

    Put, Stéphanie; Westhovens, René; Lahoutte, Tony; Matthys, Patrick

    2014-04-15

    Early diagnosis and effective monitoring of rheumatoid arthritis (RA) are important for a positive outcome. Instant treatment often results in faster reduction of inflammation and, as a consequence, less structural damage. Anatomical imaging techniques have been in use for a long time, facilitating diagnosis and monitoring of RA. However, mere imaging of anatomical structures provides little information on the processes preceding changes in synovial tissue, cartilage, and bone. Molecular imaging might facilitate more effective diagnosis and monitoring in addition to providing new information on the disease pathogenesis. A limiting factor in the development of new molecular imaging techniques is the availability of suitable probes. Here, we review which cells and molecules can be targeted in the RA joint and discuss the advances that have been made in imaging of arthritis with a focus on such molecular targets as folate receptor, F4/80, macrophage mannose receptor, E-selectin, intercellular adhesion molecule-1, phosphatidylserine, and matrix metalloproteinases. In addition, we discuss a new tool that is being introduced in the field, namely the use of nanobodies as tracers. Finally, we describe additional molecules displaying specific features in joint inflammation and propose these as potential new molecular imaging targets, more specifically receptor activator of nuclear factor κB and its ligand, chemokine receptors, vascular cell adhesion molecule-1, αVβ₃ integrin, P2X7 receptor, suppression of tumorigenicity 2, dendritic cell-specific transmembrane protein, and osteoclast-stimulatory transmembrane protein.

  3. An Adaptive Watermarking Technique for Copyright Protection of Digital Images

    Energy Technology Data Exchange (ETDEWEB)

    Park, K.S.; Lee, B.Y.; Park, S.H. [Yonsei University, Seoul (Korea); Chung, T.Y. [Kangnung National University, Kangnung (Korea)

    2002-03-01

    This paper proposes a new watermark embedding and extraction technique which extends the direct sequence spread spectrum technique. The proposed technique approximates the complexity of image and block in spatial domain using Laplacian filtering and watermark is adaptively embeded in the mid-frequency DCT components. Local parity bits are attached to higher-frequency DCT components and they are used to detect extraction errors and correct those errors. In extraction process, the proposed method boosts the higher frequency components of image and extracts the watermark by demodulation and this information is verified and adjusted by parity bits. Experimental results show it is invisible and robust to several external attacks. (author). 7 refs., 5 figs., 2 tabs.

  4. Appropriate electromagnetic techniques for imaging geothermal fracture zones

    Energy Technology Data Exchange (ETDEWEB)

    Groom, R.; Walker, P. [PetRos EiKon Incorporated, Ontario (Canada)

    1996-05-01

    Electromagnetic surface detection of fracture zones has often been approached by using the magnetotelluric method. This technique suffers greatly from the quantity and scale of the conductive inhomogeneities lying above the fracture zones. Additionally, it suffers from the inherent inability to focus the source on the target. There are no such source focusing capabilities in magnetotellurics. Accordingly, the quantity of magnetotelluric data required to resolve targets in such complex conditions can make the technique inefficient and insufficient from a cost perspective. When attempting to reveal a subsurface structure and image it, the basic physical responses at hand must be kept in mind, and the appropriate source must be utilized, which most effectively illuminates the target. A further advantage to controlled sources is that imaging techniques may be used to accentuate the response due to knowledge and control of the source.

  5. An overview of MR arthrography with emphasis on the current technique and applicational hints and tips

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Guelden [Department of Radiology, Faculty of Medicine, Ankara University, Samanpazari, 06100 Ankara (Turkey)]. E-mail: gsahin@medicine.ankara.edu.tr; Demirtas, Mehmet [Department of Hand Surgery, Faculty of Medicine, Ankara University, Samanpazari, 06100 Ankara (Turkey)

    2006-06-15

    Magnetic resonance (MR) arthrography has been investigated in every major peripheral joint of the body, and has been proven to be effective in determining the integrity of intraarticular ligamentous and fibrocartilaginous structures and in the detection or assessment of osteochondral lesions and loose bodies in selected cases. Several methods could be used to create arthrogram effect during MR imaging, however, direct MR arthrography using diluted gadolinium as the contrast agent is the most commonly used technique and is the most reliable of all. MR arthrography is useful for demonstrating labrocapsular-ligamentous abnormalities and distinguishing partial thickness rotator cuff tears from focal full thickness tears in the shoulder, identifying or excluding recurrent tears following meniscal operations in the knee, demonstrating perforations of the triangular fibrocartilage complex (TFCC) and ligaments in the wrist, showing labral tears in the hip, diagnosing ligament tears in the ankle and identifying osteochondral lesions or loose bodies in any of the aforementioned joints. In this article, an overview of techniques of MR arthrography is provided with emphasis on direct MR arthrography using diluted gadolinium as the contrast agent. The current applications of the technique in major peripheral joints are reviewed, with emphasis given to the shoulder joint where the role of this technique has become well established.

  6. Ambient Mass Spectrometry Imaging Using Direct Liquid Extraction Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia; Lanekoff, Ingela

    2015-11-13

    Mass spectrometry imaging (MSI) is a powerful analytical technique that enables label-free spatial localization and identification of molecules in complex samples.1-4 MSI applications range from forensics5 to clinical research6 and from understanding microbial communication7-8 to imaging biomolecules in tissues.1, 9-10 Recently, MSI protocols have been reviewed.11 Ambient ionization techniques enable direct analysis of complex samples under atmospheric pressure without special sample pretreatment.3, 12-16 In fact, in ambient ionization mass spectrometry, sample processing (e.g., extraction, dilution, preconcentration, or desorption) occurs during the analysis.17 This substantially speeds up analysis and eliminates any possible effects of sample preparation on the localization of molecules in the sample.3, 8, 12-14, 18-20 Venter and co-workers have classified ambient ionization techniques into three major categories based on the sample processing steps involved: 1) liquid extraction techniques, in which analyte molecules are removed from the sample and extracted into a solvent prior to ionization; 2) desorption techniques capable of generating free ions directly from substrates; and 3) desorption techniques that produce larger particles subsequently captured by an electrospray plume and ionized.17 This review focuses on localized analysis and ambient imaging of complex samples using a subset of ambient ionization methods broadly defined as “liquid extraction techniques” based on the classification introduced by Venter and co-workers.17 Specifically, we include techniques where analyte molecules are desorbed from solid or liquid samples using charged droplet bombardment, liquid extraction, physisorption, chemisorption, mechanical force, laser ablation, or laser capture microdissection. Analyte extraction is followed by soft ionization that generates ions corresponding to intact species. Some of the key advantages of liquid extraction techniques include the ease

  7. The molecular imaging approach to image infections and inflammation by nuclear medicine techniques

    NARCIS (Netherlands)

    Signore, Alberto; Glaudemans, Andor W. J. M.

    2011-01-01

    Inflammatory and infectious diseases are a heterogeneous class of diseases that may be divided into infections, acute inflammation and chronic inflammation. Radiological imaging techniques have, with the exception of functional MRI, high sensitivity but lack in specificity. Nuclear medicine

  8. A Robust Time Efficient Watermarking Technique for Stereo Images

    Directory of Open Access Journals (Sweden)

    M. A. Abdou

    2015-01-01

    Full Text Available Stereoscopic and multiview imaging techniques are used for reproducing a natural or real world scene. However, the fact that more information is displayed requires supporting technologies to ensure the storage and transmission of the sequences. Beyond these supports comes watermarking as a desirable alternative solution for copyright protection of stereo images and videos. This paper introduces a watermarking method applied to stereo images in wavelet domain. This method uses a particle swarm optimization (PSO evolutionary computation method. The aim is to solve computational complexity problems as well as satisfy an execution time that complies with normal PCs or smart phones processors. Robustness against image attacks is tested, and results are shown.

  9. A 3-Level Secure Histogram Based Image Steganography Technique

    Directory of Open Access Journals (Sweden)

    G V Chaitanya

    2013-04-01

    Full Text Available Steganography is an art that involves communication of secret data in an appropriate carrier, eg. images, audio, video, etc. with a goal to hide the very existence of embedded data so as not to arouse an eavesdropper’s suspicion. In this paper, a steganographic technique with high level of security and having a data hiding capacity close to 20% of cover image data has been developed. An adaptive and matched bit replacement method is used based on the sensitivity of Human Visual System (HVS at different intensities. The proposed algorithm ensures that the generated stego image has a PSNR greater than 38.5 and is also resistant to visual attack. A three level security is infused into the algorithm which makes data retrieval from the stego image possible only in case of having all the right keys.

  10. SAR IMAGE ENHANCEMENT BASED ON BEAM SHARPENING TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    LIYong; ZI-IANGKun-hui; ZHUDai-yin; ZHUZhao-da

    2004-01-01

    A major problem encountered in enhancing SAR image is the total loss of phase information and the unknown parameters of imaging system. The beam sharpening technique, combined with synthetic aperture radiation pattern estimation provides an approach to process this kind of data to achieve higher apparent resolution. Based on the criterion of minimizing the expected quadratic estimation error, an optimum FIR filter with a symmetrical structure is designed whose coefficients depend on the azimuth response of local isolated prominent points because this response can be approximately regarded as the synthetic aperture radiation pattern of the imaging system. The point target simulation shows that the angular resolution is improved by a ratio of almost two to one. The processing results of a live SAR image demonstrate the validity of the method.

  11. Study and Comparison of Various Techniques of Image Edge Detection

    Directory of Open Access Journals (Sweden)

    Gurjeet Singh

    2014-03-01

    Full Text Available An edge may be defined as a set of connected pixels that forms a boundary between two disjoints regions. Image Edge detection reduces the amount of data and filters out useless information, while preserving the important structural properties in an image. Edge detection plays an important role in digital image processing and practical aspects of our daily life. In this paper we studied various edge detection techniques as Prewitt, Robert, Sobel, LoG and Canny operators. On comparing them we conclude that canny edge detector performs better than all other edge detectors on various aspects such as it is adaptive in nature, performs better for noisy image, gives sharp edges, low probability of detecting false edges.

  12. Image encryption using a synchronous permutation-diffusion technique

    Science.gov (United States)

    Enayatifar, Rasul; Abdullah, Abdul Hanan; Isnin, Ismail Fauzi; Altameem, Ayman; Lee, Malrey

    2017-03-01

    In the past decade, the interest on digital images security has been increased among scientists. A synchronous permutation and diffusion technique is designed in order to protect gray-level image content while sending it through internet. To implement the proposed method, two-dimensional plain-image is converted to one dimension. Afterward, in order to reduce the sending process time, permutation and diffusion steps for any pixel are performed in the same time. The permutation step uses chaotic map and deoxyribonucleic acid (DNA) to permute a pixel, while diffusion employs DNA sequence and DNA operator to encrypt the pixel. Experimental results and extensive security analyses have been conducted to demonstrate the feasibility and validity of this proposed image encryption method.

  13. Stride for Developing a New Image Registration Technique using Mutual Information and Optimization Technique

    Directory of Open Access Journals (Sweden)

    Sumitha

    2014-01-01

    Full Text Available Registration is a fundamental task in image processing used to match two or more pictures taken, for example, at different times, from different sensors, or from different viewpoints. Specific examples of systems where image registration is a significant component include matching a target with a real-time image of a scene for target recognition, monitoring global land usage using satellite images, matching stereo images to recover shape for autonomous navigation, and aligning images from different medical modalities for diagnosis. Methods are classified according to the different aspects of mutual information based registration. The main division is in aspects of the methodology and of the application. The part on methodology describes choices made on facets such as preprocessing of images, grey value interpolation, optimization, adaptations to the mutual information measure and different types of geometrical transformations. The part on applications is a reference of the literature available on different modalities, on interpatient registration and on different anatomical objects This paper overviews the theoretical aspects of an image registration problem. The purpose of this paper is to present a survey of image registration techniques

  14. Chronic total occlusions — Current techniques and future directions

    Directory of Open Access Journals (Sweden)

    George Touma

    2015-06-01

    Full Text Available Chronic total occlusions (CTOs of coronary arteries represent a common and significant challenge to interventional cardiology. Medical therapy is often regarded as an adequate long term strategy in the management of these lesions with surgical intervention for refractory symptoms. Extensive collateralisation is used as a marker of distal coronary perfusion, further reinforcing non-invasive strategies. This together with relatively low percutaneous success rates outside of specialised centres has meant that rates of percutaneous intervention have remained low. Increasing evidence suggests that CTOs are not a benign entity. Further, symptom control and quality of life improve significantly with successful percutaneous revascularisation. Both factors have reignited interest in percutaneous modalities. The Japanese have been pioneers in the field of CTO intervention although their success rates have been difficult to replicate. New techniques and equipment developed in North America offer an alternative to the Japanese approach. These techniques focus on time, radiation and contrast minimisation. This review will assess the histopathology of CTO and shifting paradigms in CTO treatment strategies.

  15. Radiographic measurements of hallux angles: a review of current techniques.

    Science.gov (United States)

    Srivastava, Subodh; Chockalingam, N; El Fakhri, Tarek

    2010-03-01

    Radiographic angles are commonly used in patients with hallux valgus deformity to assess the severity, plan surgery, assess outcome and compare results. Many different manual methods have been used, but are prone to error. More recently computer-assisted methods using software have become available. To review the different methods that have been used to measure radiographic angles in hallux valgus. A general literature search using relevant key words was undertaken using databases such as Medline, Embase, Cinahl and Cochrane Library. REVIEW FINDINGS AND DISCUSSION: The manual methods used are prone to errors. The reliability can be improved by using standardised radiographic technique and measurement technique using specific reference points. Computer-assisted methods using software, might improve reliability of measurements. Further studies are needed to assess if these methods are easy to use, and to compare different software's that are available. Specifically designed software for the foot might further improve the reliability of radiographic measurements in hallux valgus. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  16. Skeletal muscle proteomics: current approaches, technical challenges and emerging techniques

    LENUS (Irish Health Repository)

    Ohlendieck, Kay

    2011-02-01

    Abstract Background Skeletal muscle fibres represent one of the most abundant cell types in mammals. Their highly specialised contractile and metabolic functions depend on a large number of membrane-associated proteins with very high molecular masses, proteins with extensive posttranslational modifications and components that exist in highly complex supramolecular structures. This makes it extremely difficult to perform conventional biochemical studies of potential changes in protein clusters during physiological adaptations or pathological processes. Results Skeletal muscle proteomics attempts to establish the global identification and biochemical characterisation of all members of the muscle-associated protein complement. A considerable number of proteomic studies have employed large-scale separation techniques, such as high-resolution two-dimensional gel electrophoresis or liquid chromatography, and combined them with mass spectrometry as the method of choice for high-throughput protein identification. Muscle proteomics has been applied to the comprehensive biochemical profiling of developing, maturing and aging muscle, as well as the analysis of contractile tissues undergoing physiological adaptations seen in disuse atrophy, physical exercise and chronic muscle transformation. Biomedical investigations into proteome-wide alterations in skeletal muscle tissues were also used to establish novel biomarker signatures of neuromuscular disorders. Importantly, mass spectrometric studies have confirmed the enormous complexity of posttranslational modifications in skeletal muscle proteins. Conclusions This review critically examines the scientific impact of modern muscle proteomics and discusses its successful application for a better understanding of muscle biology, but also outlines its technical limitations and emerging techniques to establish new biomarker candidates.

  17. Quantitative Image Analysis Techniques with High-Speed Schlieren Photography

    Science.gov (United States)

    Pollard, Victoria J.; Herron, Andrew J.

    2017-01-01

    Optical flow visualization techniques such as schlieren and shadowgraph photography are essential to understanding fluid flow when interpreting acquired wind tunnel test data. Output of the standard implementations of these visualization techniques in test facilities are often limited only to qualitative interpretation of the resulting images. Although various quantitative optical techniques have been developed, these techniques often require special equipment or are focused on obtaining very precise and accurate data about the visualized flow. These systems are not practical in small, production wind tunnel test facilities. However, high-speed photography capability has become a common upgrade to many test facilities in order to better capture images of unsteady flow phenomena such as oscillating shocks and flow separation. This paper describes novel techniques utilized by the authors to analyze captured high-speed schlieren and shadowgraph imagery from wind tunnel testing for quantification of observed unsteady flow frequency content. Such techniques have applications in parametric geometry studies and in small facilities where more specialized equipment may not be available.

  18. Meat quality evaluation by hyperspectral imaging technique: an overview.

    Science.gov (United States)

    Elmasry, Gamal; Barbin, Douglas F; Sun, Da-Wen; Allen, Paul

    2012-01-01

    During the last two decades, a number of methods have been developed to objectively measure meat quality attributes. Hyperspectral imaging technique as one of these methods has been regarded as a smart and promising analytical tool for analyses conducted in research and industries. Recently there has been a renewed interest in using hyperspectral imaging in quality evaluation of different food products. The main inducement for developing the hyperspectral imaging system is to integrate both spectroscopy and imaging techniques in one system to make direct identification of different components and their spatial distribution in the tested product. By combining spatial and spectral details together, hyperspectral imaging has proved to be a promising technology for objective meat quality evaluation. The literature presented in this paper clearly reveals that hyperspectral imaging approaches have a huge potential for gaining rapid information about the chemical structure and related physical properties of all types of meat. In addition to its ability for effectively quantifying and characterizing quality attributes of some important visual features of meat such as color, quality grade, marbling, maturity, and texture, it is able to measure multiple chemical constituents simultaneously without monotonous sample preparation. Although this technology has not yet been sufficiently exploited in meat process and quality assessment, its potential is promising. Developing a quality evaluation system based on hyperspectral imaging technology to assess the meat quality parameters and to ensure its authentication would bring economical benefits to the meat industry by increasing consumer confidence in the quality of the meat products. This paper provides a detailed overview of the recently developed approaches and latest research efforts exerted in hyperspectral imaging technology developed for evaluating the quality of different meat products and the possibility of its widespread

  19. Surgical treatment of scoliosis: a review of techniques currently applied

    Directory of Open Access Journals (Sweden)

    Maruyama Toru

    2008-04-01

    Full Text Available Abstract In this review, basic knowledge and recent innovation of surgical treatment for scoliosis will be described. Surgical treatment for scoliosis is indicated, in general, for the curve exceeding 45 or 50 degrees by the Cobb's method on the ground that: 1 Curves larger than 50 degrees progress even after skeletal maturity. 2 Curves of greater magnitude cause loss of pulmonary function, and much larger curves cause respiratory failure. 3 Larger the curve progress, more difficult to treat with surgery. Posterior fusion with instrumentation has been a standard of the surgical treatment for scoliosis. In modern instrumentation systems, more anchors are used to connect the rod and the spine, resulting in better correction and less frequent implant failures. Segmental pedicle screw constructs or hybrid constructs using pedicle screws, hooks, and wires are the trend of today. Anterior instrumentation surgery had been a choice of treatment for the thoracolumbar and lumbar scoliosis because better correction can be obtained with shorter fusion levels. Recently, superiority of anterior surgery for the thoracolumbar and lumbar scoliosis has been lost. Initial enthusiasm for anterior instrumentation for the thoracic curve using video assisted thoracoscopic surgery technique has faded out. Various attempts are being made with use of fusionless surgery. To control growth, epiphysiodesis on the convex side of the deformity with or without instrumentation is a technique to provide gradual progressive correction and to arrest the deterioration of the curves. To avoid fusion for skeletally immature children with spinal cord injury or myelodysplasia, vertebral wedge ostetomies are performed for the treatment of progressive paralytic scoliosis. For right thoracic curve with idiopathic scoliosis, multiple vertebral wedge osteotomies without fusion are performed. To provide correction and maintain it during the growing years while allowing spinal growth for

  20. Thickness Evaluation of Aluminium Plate Using Pulsed Eddy Current Technique

    Science.gov (United States)

    Singh, Gurpartap; Bapat, Harsh Madhukar; Singh, Bhanu Pratap; Bandyopadhyay, Manojit; Puri, Rakesh Kumar; Badodkar, Deepak Narayanrao

    2013-10-01

    This paper describes a pulsed eddy current (PEC) based non-destructive testing system used for detection of thickness variation in aluminium plate. A giant magneto-resistive sensor has been used instead of pick up coil for detecting resultant magnetic field. The PEC response signals obtained from 1 to 5 mm thickness change in aluminium plate were investigated. Two time domain features, namely peak value and time to peak, of PEC response were used for extracting information about thickness variation in aluminium plate. The variation of peak value and time to peak with thickness was compared. A program was developed to display the thickness variation of the tested sample.

  1. Theoretical assessment of electro-thermal imaging: A new technique for medical diagnosis

    Science.gov (United States)

    Carlak, H. Feza; Gencer, Nevzat G.; Besikci, Cengiz

    2016-05-01

    Breast cancer is one of the most crucial cancer types. To improve the diagnosis performance, a hybrid system is proposed through simultaneous utilization of thermal and electrical impedance imaging methods. The innovation of the approach relies on the frequency dependence of the tissue's electrical impedance which facilitates the acquisition of multiple thermal images with currents at different frequencies injected to the region of the body under inspection. The applied current and the resulting heating at the body surface are distributed based on the frequency dependent conductivity distribution. The electrical currents increase the thermal contrast on the body surface depending on the electrical properties of the tissues at the operation frequency. The technique also provides frequency dependent conductivity distribution data through thermal imaging which can be used as a basis for the detection of the breast carcinoma. Based on our findings, the contrast resolution between the healthy and cancerous tissue is increased, improving the depth-dependent imaging performance from 3 mm to 9 mm for a 1.5 mm tumor. The sensitivity of the technique can be further increased by an infrared camera with dual band imaging capability. Consequently, the proposed approach has a potential to improve the sensitivity and accuracy of medical imaging over the standard thermography.

  2. Astronomical Image Compression Techniques Based on ACC and KLT Coder

    Directory of Open Access Journals (Sweden)

    J. Schindler

    2011-01-01

    Full Text Available This paper deals with a compression of image data in applications in astronomy. Astronomical images have typical specific properties — high grayscale bit depth, size, noise occurrence and special processing algorithms. They belong to the class of scientific images. Their processing and compression is quite different from the classical approach of multimedia image processing. The database of images from BOOTES (Burst Observer and Optical Transient Exploring System has been chosen as a source of the testing signal. BOOTES is a Czech-Spanish robotic telescope for observing AGN (active galactic nuclei and the optical transient of GRB (gamma ray bursts searching. This paper discusses an approach based on an analysis of statistical properties of image data. A comparison of two irrelevancy reduction methods is presented from a scientific (astrometric and photometric point of view. The first method is based on a statistical approach, using the Karhunen-Loeve transform (KLT with uniform quantization in the spectral domain. The second technique is derived from wavelet decomposition with adaptive selection of used prediction coefficients. Finally, the comparison of three redundancy reduction methods is discussed. Multimedia format JPEG2000 and HCOMPRESS, designed especially for astronomical images, are compared with the new Astronomical Context Coder (ACC coder based on adaptive median regression.

  3. Applicability of three-dimensional imaging techniques in fetal medicine

    Energy Technology Data Exchange (ETDEWEB)

    Werner Junior, Heron; Daltro, Pedro; Gasparetto, Emerson Leandro, E-mail: heronwerner@hotmail.com [Clinica de Diagnostico Por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Santos, Jorge Lopes dos; Belmonte, Simone; Ribeiro, Gerson [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Marchiori, Edson [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2016-09-15

    Objective: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. (author)

  4. Applicability of three-dimensional imaging techniques in fetal medicine*

    Science.gov (United States)

    Werner Júnior, Heron; dos Santos, Jorge Lopes; Belmonte, Simone; Ribeiro, Gerson; Daltro, Pedro; Gasparetto, Emerson Leandro; Marchiori, Edson

    2016-01-01

    Objective To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. PMID:27818540

  5. Applicability of three-dimensional imaging techniques in fetal medicine

    Directory of Open Access Journals (Sweden)

    Heron Werner Júnior

    Full Text Available Abstract Objective: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US, magnetic resonance imaging (MRI, and, occasionally, computed tomography (CT, in order to guide additive manufacturing technology. Materials and Methods: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models.

  6. A survey of GPU-based medical image computing techniques.

    Science.gov (United States)

    Shi, Lin; Liu, Wen; Zhang, Heye; Xie, Yongming; Wang, Defeng

    2012-09-01

    Medical imaging currently plays a crucial role throughout the entire clinical applications from medical scientific research to diagnostics and treatment planning. However, medical imaging procedures are often computationally demanding due to the large three-dimensional (3D) medical datasets to process in practical clinical applications. With the rapidly enhancing performances of graphics processors, improved programming support, and excellent price-to-performance ratio, the graphics processing unit (GPU) has emerged as a competitive parallel computing platform for computationally expensive and demanding tasks in a wide range of medical image applications. The major purpose of this survey is to provide a comprehensive reference source for the starters or researchers involved in GPU-based medical image processing. Within this survey, the continuous advancement of GPU computing is reviewed and the existing traditional applications in three areas of medical image processing, namely, segmentation, registration and visualization, are surveyed. The potential advantages and associated challenges of current GPU-based medical imaging are also discussed to inspire future applications in medicine.

  7. Efficient Watermarking Technique for Digital Media (Images and Videos

    Directory of Open Access Journals (Sweden)

    Chirag Sharma

    2012-05-01

    Full Text Available In This Paper we are going to purpose an efficient Watermarking Technique for Digital Media Content Protection and Copyright Protection. Watermarking is a technique to embed hidden andunnoticeable signal into digital media in such a way that if an intruder wants to copy it, he can be caught on the basis of Copyright protection and Ownership Identification. There are many Techniques that are available to watermark the data, In our purposal we are discussing DWT Technique which is most robust to attacks rather than LSB for the protection of Digital Images. We will try to find the Quality loss after the addition of watermark after applying various attacks on Watermarked Image, the more the quality loss will be there lesser will be the efficiency of Watermarking. There will be Many Factors that can effect the quality of the Images after the addition of Watermarking that are discussed in Later Section. The Creating on GUI and Implementation of our purposed Algorithm will be realized using MATLAB.

  8. Imaging of inflammation by PET, conventional scintigraphy, and other imaging techniques.

    NARCIS (Netherlands)

    Gotthardt, M.; Bleeker-Rovers, C.P.; Boerman, O.C.; Oyen, W.J.G.

    2010-01-01

    Nuclear medicine imaging procedures play an important role in the assessment of inflammatory diseases. With the advent of 3-dimensional anatomic imaging, there has been a tendency to replace traditional planar scintigraphy by CT or MRI. Furthermore, scintigraphic techniques may have to be combined

  9. Imaging of Inflammation by PET, Conventional Scintigraphy, and Other Imaging Techniques

    NARCIS (Netherlands)

    Gotthardt, M.; Bleeker-Rovers, C.P.; Boerman, O.C.; Oyen, W.J.G.

    2013-01-01

    Nuclear medicine imaging procedures play an important role in the assessment of inflammatory diseases. With the advent of 3-dimensional anatomic imaging, there has been a tendency to replace traditional planar scintigraphy by CT or MRI. Furthermore, scintigraphic techniques may have to be combined

  10. Imaging of Inflammation by PET, Conventional Scintigraphy, and Other Imaging Techniques

    NARCIS (Netherlands)

    Gotthardt, M.; Bleeker-Rovers, C.P.; Boerman, O.C.; Oyen, W.J.G.

    2013-01-01

    Nuclear medicine imaging procedures play an important role in the assessment of inflammatory diseases. With the advent of 3-dimensional anatomic imaging, there has been a tendency to replace traditional planar scintigraphy by CT or MRI. Furthermore, scintigraphic techniques may have to be combined w

  11. Current imaging strategies for the evaluation of uterine cervical cancer.

    Science.gov (United States)

    Bourgioti, Charis; Chatoupis, Konstantinos; Moulopoulos, Lia Angela

    2016-04-28

    Uterine cervical cancer still remains an important socioeconomic issue because it largely affects women of reproductive age. Prognosis is highly depended on extent of the disease at diagnosis and, therefore, accurate staging is crucial for optimal management. Cervical cancer is clinically staged, according to International Federation of Gynecology and Obstetrics guidelines, but, currently, there is increased use of cross sectional imaging modalities [computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT)] for the study of important prognostic factors like tumor size, parametrial invasion, endocervical extension, pelvic side wall or adjacent/distal organs involvement and lymph node status. Imaging indications also include cervical cancer follow-up, evaluation of tumor response to treatment and selection of suitable candidates for less radical surgeries like radical trachelectomy for fertility preservation. The preferred imaging method for local cervical cancer evaluation is MRI; CT is equally effective for evaluation of extrauterine spread of the disease. PET-CT shows high diagnostic performance for the detection of tumor relapse and metastatic lymph nodes. The aim of this review is to familiarize radiologists with the MRI appearance of cervical carcinoma and to discuss the indications of cross sectional imaging during the course of the disease in patients with cervical carcinoma.

  12. Current imaging strategies for the evaluation of uterine cervical cancer

    Institute of Scientific and Technical Information of China (English)

    Charis Bourgioti; Konstantinos Chatoupis; Lia Angela Moulopoulos

    2016-01-01

    Uterine cervical cancer still remains an important socioeconomic issue because it largely affects women of reproductive age.Prognosis is highly depended on extent of the disease at diagnosis and,therefore,accurate staging is crucial for optimal management.Cervical cancer is clinically staged,according to International Federation of Gynecology and Obstetrics guidelines,but,currently,there is increased use of cross sectional imaging modalities [computed tomography(CT),magnetic resonance imaging(MRI),positron emission tomography-CT(PET-CT)] for the study of important prognostic factors like tumor size,parametrial invasion,endocervical extension,pelvic side wall or adjacent/distal organs involvement and lymph node status.Imaging indications also include cervical cancer follow-up,evaluation of tumor response to treatment and selection of suitable candidates for less radical surgeries like radical trachelectomy for fertility preservation.The preferred imaging method for local cervical cancer evaluation is MRI;CT is equally effective for evaluation of extrauterine spread of the disease.PETCT shows high diagnostic performance for the detection of tumor relapse and metastatic lymph nodes.The aim of this review is to familiarize radiologists with the MRI appearance of cervical carcinoma and to discuss the indications of cross sectional imaging during the course of the disease in patients with cervical carcinoma.

  13. Dual self-image technique for beam collimation

    Science.gov (United States)

    Herrera-Fernandez, Jose Maria; Sanchez-Brea, Luis Miguel; Torcal-Milla, Francisco Jose; Morlanes, Tomas; Bernabeu, Eusebio

    2016-07-01

    We propose an accurate technique for obtaining highly collimated beams, which also allows testing the collimation degree of a beam. It is based on comparing the period of two different self-images produced by a single diffraction grating. In this way, variations in the period of the diffraction grating do not affect to the measuring procedure. Self-images are acquired by two CMOS cameras and their periods are determined by fitting the variogram function of the self-images to a cosine function with polynomial envelopes. This way, loss of accuracy caused by imperfections of the measured self-images is avoided. As usual, collimation is obtained by displacing the collimation element with respect to the source along the optical axis. When the period of both self-images coincides, collimation is achieved. With this method neither a strict control of the period of the diffraction grating nor a transverse displacement, required in other techniques, are necessary. As an example, a LED considering paraxial approximation and point source illumination is collimated resulting a resolution in the divergence of the beam of δ φ =+/- 1.57 μ {rad}.

  14. Renal Graft Fibrosis and Inflammation Quantification by an Automated Fourier-Transform Infrared Imaging Technique.

    Science.gov (United States)

    Vuiblet, Vincent; Fere, Michael; Gobinet, Cyril; Birembaut, Philippe; Piot, Olivier; Rieu, Philippe

    2016-08-01

    Renal interstitial fibrosis and interstitial active inflammation are the main histologic features of renal allograft biopsy specimens. Fibrosis is currently assessed by semiquantitative subjective analysis, and color image analysis has been developed to improve the reliability and repeatability of this evaluation. However, these techniques fail to distinguish fibrosis from constitutive collagen or active inflammation. We developed an automatic, reproducible Fourier-transform infrared (FTIR) imaging-based technique for simultaneous quantification of fibrosis and inflammation in renal allograft biopsy specimens. We generated and validated a classification model using 49 renal biopsy specimens and subsequently tested the robustness of this classification algorithm on 166 renal grafts. Finally, we explored the clinical relevance of fibrosis quantification using FTIR imaging by comparing results with renal function at 3 months after transplantation (M3) and the variation of renal function between M3 and M12. We showed excellent robustness for fibrosis and inflammation classification, with >90% of renal biopsy specimens adequately classified by FTIR imaging. Finally, fibrosis quantification by FTIR imaging correlated with renal function at M3, and the variation in fibrosis between M3 and M12 correlated well with the variation in renal function over the same period. This study shows that FTIR-based analysis of renal graft biopsy specimens is a reproducible and reliable label-free technique for quantifying fibrosis and active inflammation. This technique seems to be more relevant than digital image analysis and promising for both research studies and routine clinical practice.

  15. Carotid artery stenting: Rationale, technique, and current concepts

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Hasan, E-mail: hasan.yilmaz@hcuge.c [Department of Interventional and Diagnostic Neuroradiology, University Hospital of Geneva (Switzerland); Pereira, Vitor Mendes; Narata, Ana-Paula [Department of Interventional and Diagnostic Neuroradiology, University Hospital of Geneva (Switzerland); Sztajzel, Roman [Department of Neurology, University Hospital of Geneva (Switzerland); Lovblad, Karl-Olof [Department of Interventional and Diagnostic Neuroradiology, University Hospital of Geneva (Switzerland)

    2010-07-15

    Carotid stenosis is a major risk factor for stroke. With the aging of the general population and the availability of non-invasive vascular imaging studies, the diagnosis of a carotid plaque is commonly made in medical practice. Asymptomatic and symptomatic carotid stenoses need to be considered separately because their natural history is different. Two large randomized controlled trials (RCTs) showed the effectiveness of carotid endarterectomy (CEA) in preventing ipsilateral ischemic events in patients with symptomatic severe stenosis. The benefit of surgery is much less for moderate stenosis and harmful in patients with stenosis less than 50%. Surgery has a marginal benefit in patients with asymptomatic stenosis. Improvements in medical treatment must be taken into consideration when interpreting the results of these previous trials which compared surgery against medical treatment available at the time the trials were conducted. Carotid artery stenting (CAS) might avoid the risks associated with surgery, including cranial nerve palsy, myocardial infarction, or pulmonary embolism. Therefore and additionally to well-established indications of CAS, this endovascular approach might be a valid alternative particularly in patients at high surgical risk. However, trials of endovascular treatment of carotid stenosis have failed to provide enough evidence to justify routine CAS as an alternative to CEA in patients suitable for surgery. More data from ongoing randomized trials of CEA versus CAS will be soon available. These results will help determining the role of CAS in the management of patients with carotid artery stenosis.

  16. Scene correction (precision techniques) of ERTS sensor data using digital image processing techniques

    Science.gov (United States)

    Bernstein, R.

    1974-01-01

    Techniques have been developed, implemented, and evaluated to process ERTS Return Beam Vidicon (RBV) and Multispectral Scanner (MSS) sensor data using digital image processing techniques. The RBV radiometry has been corrected to remove shading effects, and the MSS geometry and radiometry have been corrected to remove internal and external radiometric and geometric errors. The results achieved show that geometric mapping accuracy of about one picture element RMS and two picture elements (maximum) can be achieved by the use of nine ground control points. Radiometric correction of MSS and RBV sensor data has been performed to eliminate striping and shading effects to about one count accuracy. Image processing times on general purpose computers of the IBM 370/145 to 168 class are in the range of 29 to 3.2 minutes per MSS scene (4 bands). Photographic images of the fully corrected and annotated scenes have been generated from the processed data and have demonstrated excellent quality and information extraction potential.

  17. Visualizing Vertebrate Embryos with Episcopic 3D Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Stefan H. Geyer

    2009-01-01

    Full Text Available The creation of highly detailed, three-dimensional (3D computer models is essential in order to understand the evolution and development of vertebrate embryos, and the pathogenesis of hereditary diseases. A still-increasing number of methods allow for generating digital volume data sets as the basis of virtual 3D computer models. This work aims to provide a brief overview about modern volume data–generation techniques, focusing on episcopic 3D imaging methods. The technical principles, advantages, and problems of episcopic 3D imaging are described. The strengths and weaknesses in its ability to visualize embryo anatomy and labeled gene product patterns, specifically, are discussed.

  18. Image Processing Techniques and Feature Recognition in Solar Physics

    Science.gov (United States)

    Aschwanden, Markus J.

    2010-04-01

    This review presents a comprehensive and systematic overview of image-processing techniques that are used in automated feature-detection algorithms applied to solar data: i) image pre-processing procedures, ii) automated detection of spatial features, iii) automated detection and tracking of temporal features (events), and iv) post-processing tasks, such as visualization of solar imagery, cataloguing, statistics, theoretical modeling, prediction, and forecasting. For each aspect the most recent developments and science results are highlighted. We conclude with an outlook on future trends.

  19. Application of digital image processing techniques to astronomical imagery, 1979

    Science.gov (United States)

    Lorre, J. J.

    1979-01-01

    Several areas of applications of image processing to astronomy were identified and discussed. These areas include: (1) deconvolution for atmospheric seeing compensation; a comparison between maximum entropy and conventional Wiener algorithms; (2) polarization in galaxies from photographic plates; (3) time changes in M87 and methods of displaying these changes; (4) comparing emission line images in planetary nebulae; and (5) log intensity, hue saturation intensity, and principal component color enhancements of M82. Examples are presented of these techniques applied to a variety of objects.

  20. Computer image processing - The Viking experience. [digital enhancement techniques

    Science.gov (United States)

    Green, W. B.

    1977-01-01

    Computer processing of digital imagery from the Viking mission to Mars is discussed, with attention given to subjective enhancement and quantitative processing. Contrast stretching and high-pass filtering techniques of subjective enhancement are described; algorithms developed to determine optimal stretch and filtering parameters are also mentioned. In addition, geometric transformations to rectify the distortion of shapes in the field of view and to alter the apparent viewpoint of the image are considered. Perhaps the most difficult problem in quantitative processing of Viking imagery was the production of accurate color representations of Orbiter and Lander camera images.

  1. Current and future trends in marine image annotation software

    Science.gov (United States)

    Gomes-Pereira, Jose Nuno; Auger, Vincent; Beisiegel, Kolja; Benjamin, Robert; Bergmann, Melanie; Bowden, David; Buhl-Mortensen, Pal; De Leo, Fabio C.; Dionísio, Gisela; Durden, Jennifer M.; Edwards, Luke; Friedman, Ariell; Greinert, Jens; Jacobsen-Stout, Nancy; Lerner, Steve; Leslie, Murray; Nattkemper, Tim W.; Sameoto, Jessica A.; Schoening, Timm; Schouten, Ronald; Seager, James; Singh, Hanumant; Soubigou, Olivier; Tojeira, Inês; van den Beld, Inge; Dias, Frederico; Tempera, Fernando; Santos, Ricardo S.

    2016-12-01

    Given the need to describe, analyze and index large quantities of marine imagery data for exploration and monitoring activities, a range of specialized image annotation tools have been developed worldwide. Image annotation - the process of transposing objects or events represented in a video or still image to the semantic level, may involve human interactions and computer-assisted solutions. Marine image annotation software (MIAS) have enabled over 500 publications to date. We review the functioning, application trends and developments, by comparing general and advanced features of 23 different tools utilized in underwater image analysis. MIAS requiring human input are basically a graphical user interface, with a video player or image browser that recognizes a specific time code or image code, allowing to log events in a time-stamped (and/or geo-referenced) manner. MIAS differ from similar software by the capability of integrating data associated to video collection, the most simple being the position coordinates of the video recording platform. MIAS have three main characteristics: annotating events in real time, posteriorly to annotation and interact with a database. These range from simple annotation interfaces, to full onboard data management systems, with a variety of toolboxes. Advanced packages allow to input and display data from multiple sensors or multiple annotators via intranet or internet. Posterior human-mediated annotation often include tools for data display and image analysis, e.g. length, area, image segmentation, point count; and in a few cases the possibility of browsing and editing previous dive logs or to analyze the annotations. The interaction with a database allows the automatic integration of annotations from different surveys, repeated annotation and collaborative annotation of shared datasets, browsing and querying of data. Progress in the field of automated annotation is mostly in post processing, for stable platforms or still images

  2. Osteochondral tissue engineering with biphasic scaffold: current strategies and techniques.

    Science.gov (United States)

    Shimomura, Kazunori; Moriguchi, Yu; Murawski, Christopher D; Yoshikawa, Hideki; Nakamura, Norimasa

    2014-10-01

    The management of osteoarthritis (OA) remains challenging and controversial. Although several clinical options exist for the treatment of OA, regeneration of the damaged articular cartilage has proved difficult due to the limited healing capacity. With the advancements in tissue engineering and cell-based technologies over the past decade, new therapeutic options for patients with osteochondral lesions potentially exist. This review will focus on the feasibility of tissue-engineered biphasic scaffolds, which can mimic the native osteochondral complex, for osteochondral repair and highlight the recent development of these techniques toward tissue regeneration. Moreover, basic anatomy, strategy for osteochondral repair, the design and fabrication methods of scaffolds, as well as the choice of cells, growth factor, and materials will be discussed. Specifically, we focus on the latest preclinical animal studies using large animals and clinical trials with high clinical relevance. In turn, this will facilitate an understanding of the latest trends in osteochondral repair and contribute to the future application of such clinical therapies in patients with OA.

  3. Exact temporal eddy current compensation in magnetic resonance imaging systems.

    Science.gov (United States)

    Morich, M A; Lampman, D A; Dannels, W R; Goldie, F D

    1988-01-01

    A step-response method has been developed to extract the properties (amplitudes and decay time constants) of intrinsic-eddy-current-sourced magnetic fields generated in whole-body magnetic resonance imaging systems when pulsed field gradients are applied. Exact compensation for the eddy-current effect is achieved through a polynomial rooting procedure and matrix inversion once the 2 N properties of the N-term decay process are known. The output of the inversion procedure yields the required characteristics of the filter for spectrum magnitude and phase equalization. The method is described for the general case along with experimental results for one-, two-, and three-term inversions. The method's usefulness is demonstrated for the usually difficult case of long-term (200-1000-ms) eddy-current compensation. Field-gradient spectral flatness measurements over 30 mHz-100 Hz are given to validate the method.

  4. Adapting content-based image retrieval techniques for the semantic annotation of medical images.

    Science.gov (United States)

    Kumar, Ashnil; Dyer, Shane; Kim, Jinman; Li, Changyang; Leong, Philip H W; Fulham, Michael; Feng, Dagan

    2016-04-01

    The automatic annotation of medical images is a prerequisite for building comprehensive semantic archives that can be used to enhance evidence-based diagnosis, physician education, and biomedical research. Annotation also has important applications in the automatic generation of structured radiology reports. Much of the prior research work has focused on annotating images with properties such as the modality of the image, or the biological system or body region being imaged. However, many challenges remain for the annotation of high-level semantic content in medical images (e.g., presence of calcification, vessel obstruction, etc.) due to the difficulty in discovering relationships and associations between low-level image features and high-level semantic concepts. This difficulty is further compounded by the lack of labelled training data. In this paper, we present a method for the automatic semantic annotation of medical images that leverages techniques from content-based image retrieval (CBIR). CBIR is a well-established image search technology that uses quantifiable low-level image features to represent the high-level semantic content depicted in those images. Our method extends CBIR techniques to identify or retrieve a collection of labelled images that have similar low-level features and then uses this collection to determine the best high-level semantic annotations. We demonstrate our annotation method using retrieval via weighted nearest-neighbour retrieval and multi-class classification to show that our approach is viable regardless of the underlying retrieval strategy. We experimentally compared our method with several well-established baseline techniques (classification and regression) and showed that our method achieved the highest accuracy in the annotation of liver computed tomography (CT) images.

  5. Single-image rectification technique in forensic science.

    Science.gov (United States)

    González-Jorge, Higinio; Puente, Iván; Eguía, Pablo; Arias, Pedro

    2013-03-01

    Many researchers have been working in Spain to document the communal graves of those assassinated during the Spanish Civil War. This article shows the results obtained with two low-cost photogrammetric techniques for the basic documentation of forensic studies. These low-cost techniques are based on single-image rectification and the correction of the original photo displacement due to the projection and perspective distortions introduced by the lens of the camera. The capability of image rectification is tested in an excavation in the village of Loma de Montija (Burgos, Spain). The results of both techniques are compared with the more accurate data obtained from a laser scanner system RIEGL LMS-Z390i to evaluate the error in the lengths. The first technique uses a camera situated on a triangle-shaped pole at a height of 5 m and the second positions the camera over the grave using a linearly actuated device. The first technique shows measurement errors less than 6%, whereas the second shows greater errors (between 8% and 14%) owing to the positioning of the carbon-fiber cross on an uneven surface.

  6. Spatial Domain based Image Enhancement Techniques for Scanned Electron Microscope-SEM-images

    Directory of Open Access Journals (Sweden)

    Rakhi Chanana

    2011-07-01

    Full Text Available The growing need for efficiently processing and analyzing the information contained in digital images is a continuous challenge in order to apply image processing. Digital images are captured from different imaging media elements like cameras, scanned electron microscopes etc. While going through the imaging process, Images get distorted in various forms resulting in extreme dark or light areas. All these things lead to the loss of information. The goal in each case is to extract useful information. In that case, Image processing extracts useful information by applying various image enhancement and algorithms. In this paper, we have discussed a practical implementation of various enhancement methods for Scanned Electron Microscope (SEM images and their experimental results. SEM images lead to very dark and light areas in an image. While imaging the information in the front scene is not only the source of information but some scenes on the dark side can also have the useful information. Before processing any further we require to enhance such images and one of the enhancement techniques i.e. Histogram Statistics comes out to be an ideal approach.

  7. Optical Fourier techniques for medical image processing and phase contrast imaging.

    Science.gov (United States)

    Yelleswarapu, Chandra S; Kothapalli, Sri-Rajasekhar; Rao, D V G L N

    2008-04-01

    This paper briefly reviews the basics of optical Fourier techniques (OFT) and applications for medical image processing as well as phase contrast imaging of live biological specimens. Enhancement of microcalcifications in a mammogram for early diagnosis of breast cancer is the main focus. Various spatial filtering techniques such as conventional 4f filtering using a spatial mask, photoinduced polarization rotation in photosensitive materials, Fourier holography, and nonlinear transmission characteristics of optical materials are discussed for processing mammograms. We also reviewed how the intensity dependent refractive index can be exploited as a phase filter for phase contrast imaging with a coherent source. This novel approach represents a significant advance in phase contrast microscopy.

  8. Applications of Indirect Imaging techniques in X-ray binaries

    CERN Document Server

    Harlaftis, E T

    2000-01-01

    A review is given on aspects of indirect imaging techniques in X-ray binaries which are used as diagnostics tools for probing the X-ray dominated accretion disc physics. These techniques utilize observed properties such as the emission line profile variability, the time delays between simultaneous optical/X-ray light curves curves, the light curves of eclipsing systems and the pulsed emission from the compact object in order to reconstruct the accretion disc's line emissivity (Doppler tomography), the irradiated disc and heated secondary (echo mapping), the outer disc structure (modified eclipse mapping) and the accreting regions onto the compact object, respectively.

  9. Imaging evaluation of complications of hip arthroplasty: review of current concepts and imaging findings.

    Science.gov (United States)

    Awan, Omer; Chen, Lina; Resnik, Charles S

    2013-11-01

    Total hip arthroplasty has evolved along with improvements in component materials and design. The radiologist must accurately diagnose associated complications with imaging methods and stay informed about newer complications associated with innovations in surgical technique, prosthetic design, and novel materials. This pictorial essay presents clinical and imaging correlation of modern hip arthroplasty complications, with an emphasis on the most common complications of instability, aseptic loosening, and infection as well as those complications associated with contemporary metal-on-metal arthroplasty.

  10. Image Techniques for Identifying Sea-Ice Parameters

    Directory of Open Access Journals (Sweden)

    Qin Zhang

    2014-10-01

    Full Text Available The estimation of ice forces are critical to Dynamic Positioning (DP operations in Arctic waters. Ice conditions are important for the analysis of ice-structure interaction in an ice field. To monitor sea-ice conditions, cameras are used as field observation sensors on mobile sensor platforms in Arctic. Various image processing techniques, such as Otsu thresholding, k-means clustering, distance transform, Gradient Vector Flow (GVF Snake, mathematical morphology, are then applied to obtain ice concentration, ice types, and floe size distribution from sea-ice images to ensure safe operations of structures in ice covered regions. Those techniques yield acceptable results, and their effectiveness are demonstrated in case studies.

  11. BaTMAn: Bayesian Technique for Multi-image Analysis

    CERN Document Server

    Casado, J; García-Benito, R; Guidi, G; Choudhury, O S; Bellocchi, E; Sánchez, S; Díaz, A I

    2016-01-01

    This paper describes the Bayesian Technique for Multi-image Analysis (BaTMAn), a novel image segmentation technique based on Bayesian statistics, whose main purpose is to characterize an astronomical dataset containing spatial information and perform a tessellation based on the measurements and errors provided as input. The algorithm will iteratively merge spatial elements as long as they are statistically consistent with carrying the same information (i.e. signal compatible with being identical within the errors). We illustrate its operation and performance with a set of test cases that comprises both synthetic and real Integral-Field Spectroscopic (IFS) data. Our results show that the segmentations obtained by BaTMAn adapt to the underlying structure of the data, regardless of the precise details of their morphology and the statistical properties of the noise. The quality of the recovered signal represents an improvement with respect to the input, especially in those regions where the signal is actually con...

  12. A Novel Technique for Prealignment in Multimodality Medical Image Registration

    Directory of Open Access Journals (Sweden)

    Wu Zhou

    2014-01-01

    Full Text Available Image pair is often aligned initially based on a rigid or affine transformation before a deformable registration method is applied in medical image registration. Inappropriate initial registration may compromise the registration speed or impede the convergence of the optimization algorithm. In this work, a novel technique was proposed for prealignment in both monomodality and multimodality image registration based on statistical correlation of gradient information. A simple and robust algorithm was proposed to determine the rotational differences between two images based on orientation histogram matching accumulated from local orientation of each pixel without any feature extraction. Experimental results showed that it was effective to acquire the orientation angle between two unregistered images with advantages over the existed method based on edge-map in multimodalities. Applying the orientation detection into the registration of CT/MR, T1/T2 MRI, and monomadality images with respect to rigid and nonrigid deformation improved the chances of finding the global optimization of the registration and reduced the search space of optimization.

  13. An imaging evaluation of the simultaneously integrated boost breast radiotherapy technique

    Energy Technology Data Exchange (ETDEWEB)

    Turley, Jessica; Claridge Mackonis, Elizabeth [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales (Australia)

    2015-09-15

    To evaluate in-field megavoltage (MV) imaging of simultaneously integrated boost (SIB) breast fields to determine its feasibility in treatment verification for the SIB breast radiotherapy technique, and to assess whether the current-imaging protocol and treatment margins are sufficient. For nine patients undergoing SIB breast radiotherapy, in-field MV images of the SIB fields were acquired on days that regular treatment verification imaging was performed. The in-field images were matched offline according to the scar wire on digitally reconstructed radiographs. The offline image correction results were then applied to a margin recipe formula to calculate safe margins that account for random and systematic uncertainties in the position of the boost volume when an offline correction protocol has been applied. After offline assessment of the acquired images, 96% were within the tolerance set in the current department-imaging protocol. Retrospectively performing the maximum position deviations on the Eclipse™ treatment planning system demonstrated that the clinical target volume (CTV) boost received a minimum dose difference of 0.4% and a maximum dose difference of 1.4% less than planned. Furthermore, applying our results to the Van Herk margin formula to ensure that 90% of patients receive 95% of the prescribed dose, the calculated CTV margins were comparable to the current departmental procedure used. Based on the in-field boost images acquired and the feasible application of these results to the margin formula the current CTV-planning target volume margins used are appropriate for the accurate treatment of the SIB boost volume without additional imaging.

  14. Rapid Inversion Imaging Techniques for Deep Transient Electromagnetic Sounding Data

    Institute of Scientific and Technical Information of China (English)

    ChenBenchi; Shaomin; HeZhanxiang; LiuHong

    2003-01-01

    This paper introduces two types of rapid inversion imaging techniques for long offset transient electromagnetic sounding: namely S-inversing algorithm based on the conductive sheet model and quasi-wave equation based on wavefield transform. The corresponding software was developed with VC++. Application of the algorithms to the processing of the real Lotem data from the western part of China proved that two the algorithms and the developed software package are effective, fast and stable.

  15. Comparison of Image Processing Techniques using Random Noise Radar

    Science.gov (United States)

    2014-03-27

    pseudo - random noise . The noise waveforms employed by the radar systems 9 are generally white and Gaussian, that is, the waveform’s power...2010. [5] Hardin, Joshua A. “Information Encoding on a Pseudo Random Noise Radar Waveform”, 2013. [6] Jackson, Julie A. “EENG 668/714 Advanced Radar ...COMPARISON OF IMAGE PROCESSING TECHNIQUES USING RANDOM NOISE RADAR THESIS Jesse Robert B. Cruz, Capt, USAF AFIT-ENG-14-M-22 DEPARTMENT OF THE

  16. Analysis of Cultural Heritage by Accelerator Techniques and Analytical Imaging

    Science.gov (United States)

    Ide-Ektessabi, Ari; Toque, Jay Arre; Murayama, Yusuke

    2011-12-01

    In this paper we present the result of experimental investigation using two very important accelerator techniques: (1) synchrotron radiation XRF and XAFS; and (2) accelerator mass spectrometry and multispectral analytical imaging for the investigation of cultural heritage. We also want to introduce a complementary approach to the investigation of artworks which is noninvasive and nondestructive that can be applied in situ. Four major projects will be discussed to illustrate the potential applications of these accelerator and analytical imaging techniques: (1) investigation of Mongolian Textile (Genghis Khan and Kublai Khan Period) using XRF, AMS and electron microscopy; (2) XRF studies of pigments collected from Korean Buddhist paintings; (3) creating a database of elemental composition and spectral reflectance of more than 1000 Japanese pigments which have been used for traditional Japanese paintings; and (4) visible light-near infrared spectroscopy and multispectral imaging of degraded malachite and azurite. The XRF measurements of the Japanese and Korean pigments could be used to complement the results of pigment identification by analytical imaging through spectral reflectance reconstruction. On the other hand, analysis of the Mongolian textiles revealed that they were produced between 12th and 13th century. Elemental analysis of the samples showed that they contained traces of gold, copper, iron and titanium. Based on the age and trace elements in the samples, it was concluded that the textiles were produced during the height of power of the Mongol empire, which makes them a valuable cultural heritage. Finally, the analysis of the degraded and discolored malachite and azurite demonstrates how multispectral analytical imaging could be used to complement the results of high energy-based techniques.

  17. Reverse Time Migration: A Seismic Imaging Technique Applied to Synthetic Ultrasonic Data

    Directory of Open Access Journals (Sweden)

    Sabine Müller

    2012-01-01

    Full Text Available Ultrasonic echo testing is a more and more frequently used technique in civil engineering to investigate concrete building elements, to measure thickness as well as to locate and characterise built-in components or inhomogeneities. Currently the Synthetic Aperture Focusing Technique (SAFT, which is closely related to Kirchhoff migration, is used in most cases for imaging. However, this method is known to have difficulties to image steeply dipping interfaces as well as lower boundaries of tubes, voids or similar objects. We have transferred a processing technique from geophysics, the Reverse Time Migration (RTM method, to improve the imaging of complicated geometries. By using the information from wide angle reflections as well as from multiple events there are fewer limitations compared to SAFT. As a drawback the required computing power is significantly higher compared to the techniques currently used. Synthetic experiments have been performed on polyamide and concrete specimens to show the improvements compared to SAFT. We have been able to image vertical interfaces of step-like structures as well as the lower boundaries of circular objects. It has been shown that RTM is a step forward for ultrasonic testing in civil engineering.

  18. ONLINE GRINDING WHEEL WEAR COMPENSATION BY IMAGE BASED MEASURING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    WAN Daping; HU Dejin; WU Qi; ZHANG Yonghong

    2006-01-01

    Automatic compensation of grinding wheel wear in dry grinding is accomplished by an image based online measurement method. A kind of PC-based charge-coupled device image recognition system is schemed out, which detects the topography changes of the grinding wheel surface. Profile data, which corresponds to the wear and the topography, is measured by using a digital image processing method. The grinding wheel wear is evaluated by analyzing the position deviation of the grinding wheel edge. The online wear compensation is achieved according to the measure results. The precise detection and automatic compensation system is integrated into an open structure CNC curve grinding machine. A practical application is carried out to fulfil the precision curve grinding. The experimental results confirm the benefits of the proposed techniques, and the online detection accuracy is less than 5 μm. The grinding machine provides higher precision according to the in-process grinding wheel error compensation.

  19. Processing techniques for digital sonar images from GLORIA.

    Science.gov (United States)

    Chavez, P.S.

    1986-01-01

    Image processing techniques have been developed to handle data from one of the newest members of the remote sensing family of digital imaging systems. This paper discusses software to process data collected by the GLORIA (Geological Long Range Inclined Asdic) sonar imaging system, designed and built by the Institute of Oceanographic Sciences (IOS) in England, to correct for both geometric and radiometric distortions that exist in the original 'raw' data. Preprocessing algorithms that are GLORIA-specific include corrections for slant-range geometry, water column offset, aspect ratio distortion, changes in the ship's velocity, speckle noise, and shading problems caused by the power drop-off which occurs as a function of range.-from Author

  20. Light and sound - emerging imaging techniques for inflammatory bowel disease

    Science.gov (United States)

    Knieling, Ferdinand; Waldner, Maximilian J

    2016-01-01

    Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography. PMID:27433080

  1. Steganographic Techniques of Data Hiding Using Digital Images (Review Paper

    Directory of Open Access Journals (Sweden)

    Babloo Saha

    2012-01-01

    Full Text Available Steganography is an art that involves communication of secret data in an appropriate carrier, e.g., image, audio, video or TCP/IP header file. Steganography’s goal is to hide the very existence of embedded data so as not to arouse an eavesdropper’s suspicion. For hiding secret data in digital images, large varieties of steganographic techniques are available, some are more complex than others, and all of them have their respective pros and cons. Steganography has various useful applications and the technique employed depends on the requirements of the application to be designed for. For instance. applications may require absolute invisibility of the secret data, larger secret data to be hidden or high degree of robustness of the carrier. This paper intends to give thorough understanding and evolution of different existing digital image steganography techniques of data hiding in spatial, transform and compression domains. It covers and integrates recent research work without going in to much detail of steganalysis, which is the art and science of defeating steganography.Defence Science Journal, 2012, 62(1, pp.11-18, DOI:http://dx.doi.org/10.14429/dsj.62.1436

  2. Non-integer expansion embedding techniques for reversible image watermarking

    Science.gov (United States)

    Xiang, Shijun; Wang, Yi

    2015-12-01

    This work aims at reducing the embedding distortion of prediction-error expansion (PE)-based reversible watermarking. In the classical PE embedding method proposed by Thodi and Rodriguez, the predicted value is rounded to integer number for integer prediction-error expansion (IPE) embedding. The rounding operation makes a constraint on a predictor's performance. In this paper, we propose a non-integer PE (NIPE) embedding approach, which can proceed non-integer prediction errors for embedding data into an audio or image file by only expanding integer element of a prediction error while keeping its fractional element unchanged. The advantage of the NIPE embedding technique is that the NIPE technique can really bring a predictor into full play by estimating a sample/pixel in a noncausal way in a single pass since there is no rounding operation. A new noncausal image prediction method to estimate a pixel with four immediate pixels in a single pass is included in the proposed scheme. The proposed noncausal image predictor can provide better performance than Sachnev et al.'s noncausal double-set prediction method (where data prediction in two passes brings a distortion problem due to the fact that half of the pixels were predicted with the watermarked pixels). In comparison with existing several state-of-the-art works, experimental results have shown that the NIPE technique with the new noncausal prediction strategy can reduce the embedding distortion for the same embedding payload.

  3. Hiding Data in Images Using New Random Technique

    Directory of Open Access Journals (Sweden)

    Obaida Mohammad Awad Al-Hazaimeh

    2012-07-01

    Full Text Available Steganography is the art of hiding the fact that communication is taking place by hiding information in other information. In the field of Data Communication, Steganography play a major role. The transmission of information via the Internet may expose it to detect and theft. Some solution to be discussed is how to passing information in a manner that the very existence of the message is unknown in order to repel attention of the potential attacker. We focus on the Least Significant Bit (LSB technique which is the most common Steganographic technique is employed in this paper. An improvement to this technique is suggested by randomly inserting the bits of the message in the image to produce more secured system. In this paper, the security goals were enhanced via a proposed cryptosystems to maintain the security on the Cover-image. The proposed solution consists of a simple, but strong to hiding the text data and the human eye would be unable to notice the hidden data in the Stego-image.

  4. Speckle noise reduction in ultrasound images using a discrete wavelet transform-based image fusion technique.

    Science.gov (United States)

    Choi, Hyun Ho; Lee, Ju Hwan; Kim, Sung Min; Park, Sung Yun

    2015-01-01

    Here, the speckle noise in ultrasonic images is removed using an image fusion-based denoising method. To optimize the denoising performance, each discrete wavelet transform (DWT) and filtering technique was analyzed and compared. In addition, the performances were compared in order to derive the optimal input conditions. To evaluate the speckle noise removal performance, an image fusion algorithm was applied to the ultrasound images, and comparatively analyzed with the original image without the algorithm. As a result, applying DWT and filtering techniques caused information loss and noise characteristics, and did not represent the most significant noise reduction performance. Conversely, an image fusion method applying SRAD-original conditions preserved the key information in the original image, and the speckle noise was removed. Based on such characteristics, the input conditions of SRAD-original had the best denoising performance with the ultrasound images. From this study, the best denoising technique proposed based on the results was confirmed to have a high potential for clinical application.

  5. IMAGE ENCRYPTION TECHNIQUES USING CHAOTIC SCHEMES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Monisha Sharma

    2010-06-01

    Full Text Available Cryptography is about communication in the presence of an adversary. It encompasses many problems like encryption, authentication, and key distribution to name a few. The field of modern cryptography providesa theoretical foundation based on which one can understand what exactly these problems are, how to evaluate protocols that purport to solve them and how to build protocols in whose security one can haveconfidence. Advanced digital technologies have made multimedia data widely available. Recently, multimedia applications become common in practice and thus security of multimedia data has become main concern.The basic issues pertaining to the problem of encryption has been discussed and also a survey on image encryption techniques based on chaotic schemes has been dealt in the present communication.The chaotic image encryption can be developed by using properties of chaos including deterministic dynamics, unpredictable behavior and non-linear transform. This concept leads to techniques that can simultaneously provide security functions and an overall visualcheck, which might be suitable in some applications. Digital images are widely used in various applications, that include military, legal and medical systems and these applications need to control access toimages and provide the means to verify integrity of images.

  6. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

    Science.gov (United States)

    Álvarez López, Yuri; Martínez Lorenzo, José Ángel

    2017-01-01

    One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated. PMID:28098841

  7. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers.

    Science.gov (United States)

    López, Yuri Álvarez; Lorenzo, José Ángel Martínez

    2017-01-15

    One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

  8. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

    Directory of Open Access Journals (Sweden)

    Yuri Álvarez López

    2017-01-01

    Full Text Available One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

  9. Application of magnetic resonance techniques for imaging tumour physiology

    Energy Technology Data Exchange (ETDEWEB)

    Stubbs, M. [Saint George' s Hospital Medical School, London (United Kingdom). Dept. of Biochemistry

    1999-07-01

    Magnetic resonance (MR) techniques have the unique ability to measure in vivo the biochemical content of living tissue in the body in a dynamic, non-invasive and non-destructive manner. MR also permits serial investigations of steady-state tumour physiology and biochemistry, as well as the response of a tumour to treatment. Magnetic resonance imaging (MRI), Magnetic resonance spectroscopy (MRS) and a mixture of the two techniques (spectroscopic imaging) allow some physiological parameters, for example pH, to be 'imaged'. Using these methods, information on tissue bioenergetics and phospolipid membrane turnover, pH, hypoxia, oxygenation, and various aspects of vascularity including blood flow, angiogenesis, permeability and vascular volume can be obtained. In addition, MRS methods can be used for monitoring anticancer drugs (e.g. 5FU, ifosfamide) and their metabolites at their sites of action. The role of these state-of-the-art MR methods in imaging tumour physiology and their potential role in the clinic are discussed. (orig.)

  10. Adenomyosis: usual and unusual imaging manifestations, pitfalls, and problem-solving MR imaging techniques.

    Science.gov (United States)

    Takeuchi, Mayumi; Matsuzaki, Kenji

    2011-01-01

    Adenomyosis is a common nonneoplastic gynecologic disease characterized by the presence of ectopic endometrium within the myometrium. On T2-weighted magnetic resonance (MR) images, typical adenomyosis appears as an ill-demarcated low-signal-intensity lesion with uterine enlargement. However, various physiologic or pathologic states such as amount of functional endometrial tissue, phase of the menstrual cycle, endogenous hormonal abnormality, and exogenous hormonal stimulation may affect the MR imaging appearance of adenomyosis and may result in a tumorlike appearance. Problem-solving MR imaging techniques used in diagnosis of adenomyosis include diffusion-weighted imaging, susceptibility-weighted imaging, hydrogen 1 MR spectroscopy, cine MR imaging, and high-resolution MR imaging at 3 T. Adenomyotic lesions that show high signal intensity relative to the outer myometrium on T2-weighted images mimic malignancies such as leiomyosarcoma and endometrial stromal sarcoma. In these cases, a relatively high apparent diffusion coefficient at diffusion-weighted imaging and a low choline peak at MR spectroscopy are suggestive of a benign lesion. Small hemorrhagic foci suggestive of an adenomyotic lesion are well demonstrated as signal voids at susceptibility-weighted imaging. Cine MR imaging is useful in differentiating transient myometrial contraction from focal adenomyosis. High-resolution MR imaging at 3 T demonstrates anatomically detailed structures and may improve diagnostic accuracy in differentiating adenomyosis from its mimics, such as low-grade endometrial stromal sarcoma.

  11. High-resolution Imaging Techniques for the Assessment of Osteoporosis

    Science.gov (United States)

    Krug, Roland; Burghardt, Andrew J.; Majumdar, Sharmila; Link, Thomas M.

    2010-01-01

    Synopsis The importance of assessing the bone’s microarchitectural make-up in addition to its mineral density in the context of osteoporosis has been emphasized in a number of publications. The high spatial resolution required to resolve the bone’s microstructure in a clinically feasible scan time is challenging. Currently, the best suited modalities meeting these requirements in vivo are high-resolution peripheral quantitative imaging (HR-pQCT) and magnetic resonance imaging (MRI). Whereas HR-pQCT is limited to peripheral skeleton regions like the wrist and ankle, MRI can also image other sites like the proximal femur but usually with lower spatial resolution. In addition Multidetector-CT has been used for high-resolution imaging of trabecular bone structure, however, the radiation dose is a limiting factor. This article provides an overview of the different modalities, technical requirements and recent developments in this emerging field. Details regarding imaging protocols as well as image post-processing methods for bone structure quantification are discussed. PMID:20609895

  12. Image-Processing Techniques for the Creation of Presentation-Quality Astronomical Images

    CERN Document Server

    Rector, T A; Frattare, L M; English, J; Puuohau-Pummill, K

    2004-01-01

    The quality of modern astronomical data, the power of modern computers and the agility of current image-processing software enable the creation of high-quality images in a purely digital form. The combination of these technological advancements has created a new ability to make color astronomical images. And in many ways it has led to a new philosophy towards how to create them. A practical guide is presented on how to generate astronomical images from research data with powerful image-processing programs. These programs use a layering metaphor that allows for an unlimited number of astronomical datasets to be combined in any desired color scheme, creating an immense parameter space to be explored using an iterative approach. Several examples of image creation are presented. A philosophy is also presented on how to use color and composition to create images that simultaneously highlight scientific detail and are aesthetically appealing. This philosophy is necessary because most datasets do not correspond to t...

  13. Analysis of filtering techniques and image quality in pixel duplicated images

    Science.gov (United States)

    Mehrubeoglu, Mehrube; McLauchlan, Lifford

    2009-08-01

    When images undergo filtering operations, valuable information can be lost besides the intended noise or frequencies due to averaging of neighboring pixels. When the image is enlarged by duplicating pixels, such filtering effects can be reduced and more information retained, which could be critical when analyzing image content automatically. Analysis of retinal images could reveal many diseases at early stage as long as minor changes that depart from a normal retinal scan can be identified and enhanced. In this paper, typical filtering techniques are applied to an early stage diabetic retinopathy image which has undergone digital pixel duplication. The same techniques are applied to the original images for comparison. The effects of filtering are then demonstrated for both pixel duplicated and original images to show the information retention capability of pixel duplication. Image quality is computed based on published metrics. Our analysis shows that pixel duplication is effective in retaining information on smoothing operations such as mean filtering in the spatial domain, as well as lowpass and highpass filtering in the frequency domain, based on the filter window size. Blocking effects due to image compression and pixel duplication become apparent in frequency analysis.

  14. Magnetic particle imaging: current developments and future directions

    Directory of Open Access Journals (Sweden)

    Panagiotopoulos N

    2015-04-01

    Full Text Available Nikolaos Panagiotopoulos,1 Robert L Duschka,1 Mandy Ahlborg,2 Gael Bringout,2 Christina Debbeler,2 Matthias Graeser,2 Christian Kaethner,2 Kerstin Lüdtke-Buzug,2 Hanne Medimagh,2 Jan Stelzner,2 Thorsten M Buzug,2 Jörg Barkhausen,1 Florian M Vogt,1 Julian Haegele1 1Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig Holstein, Campus Lübeck, 2Institute of Medical Engineering, University of Lübeck, Lübeck, Germany Abstract: Magnetic particle imaging (MPI is a novel imaging method that was first proposed by Gleich and Weizenecker in 2005. Applying static and dynamic magnetic fields, MPI exploits the unique characteristics of superparamagnetic iron oxide nanoparticles (SPIONs. The SPIONs’ response allows a three-dimensional visualization of their distribution in space with a superb contrast, a very high temporal and good spatial resolution. Essentially, it is the SPIONs’ superparamagnetic characteristics, the fact that they are magnetically saturable, and the harmonic composition of the SPIONs’ response that make MPI possible at all. As SPIONs are the essential element of MPI, the development of customized nanoparticles is pursued with the greatest effort by many groups. Their objective is the creation of a SPION or a conglomerate of particles that will feature a much higher MPI performance than nanoparticles currently available commercially. A particle’s MPI performance and suitability is characterized by parameters such as the strength of its MPI signal, its biocompatibility, or its pharmacokinetics. Some of the most important adjuster bolts to tune them are the particles’ iron core and hydrodynamic diameter, their anisotropy, the composition of the particles’ suspension, and their coating. As a three-dimensional, real-time imaging modality that is free of ionizing radiation, MPI appears ideally suited for applications such as vascular imaging and interventions as well as cellular and targeted imaging. A number

  15. Image Currents in Azimuthally Inhomogeneous Metallic Beam Pipes

    CERN Document Server

    Caspers, Friedhelm; Palumbo, L; Ruggiero, F

    2001-01-01

    We consider an ultra-relativistic particle travelling on-axis in an infinitely long cylindrical metallic beam pipe with azimuthally varying conductivity. A semi-analytical solution, obtained by applying approximate boundary conditions, predicts an image current distribution on the pipe walls practically independent of the azimuth, at least in the frequency range relevant for future machines such as the LHC. We discuss numerical simulations and bench measurements which confirm the theoretical predictions. Implications for the beam-induced ohmic losses in the copper coated, welded LHC beam screen are also addressed.

  16. Image currents in azimuthally inhomogeneous metallic beam pipes

    Directory of Open Access Journals (Sweden)

    A. Mostacci

    2005-08-01

    Full Text Available We consider an ultrarelativistic particle traveling on axis in an infinitely long cylindrical metallic beam pipe with azimuthally varying conductivity. For a circular geometry, a semianalytical solution is obtained using the Green functions and applying approximate boundary conditions for conductors. The theory predicts an image current distribution on the pipe walls practically independent of the azimuth, at least in the frequency range relevant for future machines such as the LHC. Numerical electromagnetic simulations and bench measurements confirm the theoretical predictions. Implications for the beam-induced heating in the copper-coated, welded LHC beam screen are also addressed.

  17. Amyloid plaque imaging in vivo: current achievement and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, Agneta [Karolinska University Hospital Huddinge, Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Division of Alzheimer Neurobiology, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Geriatric Medicine, Stockholm (Sweden)

    2008-03-15

    Alzheimer's disease (AD) is a very complex neurodegenerative disorder, the exact cause of which is still not known. The major histopathological features, amyloid plaques and neurofibrillary tangles, already described by Alois Alzheimer, have been the focus in research for decades. Despite a probable whole cascade of events in the brain leading to impairment of cognition, amyloid is still the target for diagnosis and treatment. The rapid development of molecular imaging techniques now allows imaging of amyloid plaques in vivo in Alzheimer patients by PET amyloid ligands such as Pittsburgh compound B (PIB). Studies so far have revealed high {sup 11}C-PIB retention in brain at prodromal stages of AD and a possibility to discriminate AD from other dementia disorders by {sup 11}C-PIB. Ongoing studies are focussing to understand the relationship between brain and CSF amyloid processes and cognitive processes. In vivo imaging of amyloid will be important for early diagnosis and evaluation of new anti-amyloid therapies in AD. (orig.)

  18. Sedimentology of Martian Gravels from Mardi Twilight Imaging: Techniques

    Science.gov (United States)

    Garvin, James B.; Malin, Michael C.; Minitti, M. E.

    2014-01-01

    Quantitative sedimentologic analysis of gravel surfaces dominated by pebble-sized clasts has been employed in an effort to untangle aspects of the provenance of surface sediments on Mars using Curiosity's MARDI nadir-viewing camera operated at twilight Images have been systematically acquired since sol 310 providing a representative sample of gravel-covered surfaces since the rover departed the Shaler region. The MARDI Twilight imaging dataset offers approximately 1 millimeter spatial resolution (slightly out of focus) for patches beneath the rover that cover just under 1 m2 in area, under illumination that makes clast size and inter-clast spacing analysis relatively straightforward using semi- automated codes developed for use with nadir images. Twilight images are utilized for these analyses in order to reduce light scattering off dust deposited on the front MARDI lens element during the terminal stages of Curiosity's entry, descent and landing. Such scattering is worse when imaging bright, directly-illuminated surfaces; twilight imaging times yield diffusely-illuminated surfaces that improve the clarity of the resulting MARDI product. Twilight images are obtained between 10-30 minutes after local sunset, governed by the timing of the end of the no-heat window for the camera. Techniques were also utilized to examine data terrestrial locations (the Kau Desert in Hawaii and near Askja Caldera in Iceland). Methods employed include log hyperbolic size distribution (LHD) analysis and Delauney Triangulation (DT) inter-clast spacing analysis. This work extends the initial results reported in Yingst et al., that covered the initial landing zone, to the Rapid-Transit Route (RTR) towards Mount Sharp.

  19. A computer code to simulate X-ray imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Duvauchelle, Philippe E-mail: philippe.duvauchelle@insa-lyon.fr; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

    2000-09-01

    A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests.

  20. Imaging photonic crystals using Fourier plane imaging and Fourier ptychographic microscopy techniques implemented with a computer controlled hemispherical digital condenser

    Science.gov (United States)

    Sen, Sanchari; Desai, Darshan B.; Alsubaie, Meznh H.; Zhelyeznyakov, Maksym V.; Molina, L.; Sarraf, Hamed Sari; Bernussi, Ayrton A.; Peralta, Luis Grave de

    2017-01-01

    Fourier plane imaging (FPIM) and Fourier ptychographic (FPM) microscopy techniques were used to image photonic crystals. A computer-controlled hemispherical digital condenser provided required sample illumination with variable inclination. Notable improvement in image resolution was obtained with both methods. However, it was determined that the FPM technique cannot surpass the Rayleigh resolution limit when imaging photonic crystals.

  1. Pheochromocytoma and Paraganglioma: Current Functional and Future Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Elise M Blanchet

    2012-01-01

    Full Text Available Paragangliomas are neural crest-derived tumors, arising either from chromaffin sympathetic tissue (in adrenal, abdominal, intra-pelvic or thoracic paraganglia or from parasympathetic tissue (in head and neck paraganglia. They have a specific cellular metabolism, with the ability to synthesize, store and secrete catecholamines (although most head and neck paragangliomas do not secrete any catecholamines. This disease is rare and also very heterogeneous, with various presentations (e.g., in regards to localization, multifocality, potential to metastasize, biochemical phenotype, and genetic background. With growing knowledge, notably about the pathophysiology and genetic background, guidelines are evolving rapidly. In this context, functional imaging is a challenge for the management of paragangliomas.Nuclear imaging has been used for exploring paragangliomas for the last three decades, with MIBG historically as the first-line exam. Tracers used in paragangliomas can be grouped in three different categories. Agents that specifically target catecholamine synthesis, storage, and secretion pathways include: 123 and 131I-metaiodobenzylguanidine (123/131I-MIBG, 18F-fluorodopamine (18F-FDA, and 18F-fluorodihydroxyphenylalanine (18F-FDOPA. Agents that bind somatostatin receptors include 111In-pentetreotide and 68Ga-labelled somatostatin analog peptides. The non-specific agent most commonly used in paragangliomas is 18F-fluorodeoxyglucose (18F-FDG. This review will first describe conventional scintigraphic exams that are used for imaging paragangliomas. In the second part we will emphasize the interest in new PET approaches (specific and non-specific, considering the growing knowledge about genetic background and pathophysiology, with the aim of understanding how tumors behave, and optimally adjusting imaging technique for each tumor type.

  2. Hereditary spherocytosis and partial splenectomy in children: review of surgical technique and the role of imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, Caroline L. [Duke University Medical Center, Department of Radiology, Box 3808, Durham, NC (United States); Rice, Henry E. [Duke University Medical Center, Department of Surgery, Durham, NC (United States)

    2010-07-15

    The risks associated with total splenectomy, including overwhelming postsplenectomy infection, have led to an interest in the use of partial splenectomy as an alternative surgical option for children with congenital hemolytic anemias and hypersplenism. Partial splenectomy, a procedure designed to remove enough spleen to improve anemia and avoid complications of splenic sequestration while preserving splenic function, has shown promise in children. Radiologic imaging is essential for the preoperative evaluation and postoperative care for children undergoing partial splenectomy and offers a broad range of critical clinical information essential for care of these complex children. It is imperative for radiologists involved in the care of these children to be familiar with the surgical technique and imaging options for these procedures. This article reviews the surgical technique as well as the current status of various diagnostic imaging options used for children undergoing partial splenectomy, highlighting technical aspects and specific clinical information obtained by each modality. (orig.)

  3. Nonlinear plasmonic imaging techniques and their biological applications

    Science.gov (United States)

    Deka, Gitanjal; Sun, Chi-Kuang; Fujita, Katsumasa; Chu, Shi-Wei

    2017-01-01

    Nonlinear optics, when combined with microscopy, is known to provide advantages including novel contrast, deep tissue observation, and minimal invasiveness. In addition, special nonlinearities, such as switch on/off and saturation, can enhance the spatial resolution below the diffraction limit, revolutionizing the field of optical microscopy. These nonlinear imaging techniques are extremely useful for biological studies on various scales from molecules to cells to tissues. Nevertheless, in most cases, nonlinear optical interaction requires strong illumination, typically at least gigawatts per square centimeter intensity. Such strong illumination can cause significant phototoxicity or even photodamage to fragile biological samples. Therefore, it is highly desirable to find mechanisms that allow the reduction of illumination intensity. Surface plasmon, which is the collective oscillation of electrons in metal under light excitation, is capable of significantly enhancing the local field around the metal nanostructures and thus boosting up the efficiency of nonlinear optical interactions of the surrounding materials or of the metal itself. In this mini-review, we discuss the recent progress of plasmonics in nonlinear optical microscopy with a special focus on biological applications. The advancement of nonlinear imaging modalities (including incoherent/coherent Raman scattering, two/three-photon luminescence, and second/third harmonic generations that have been amalgamated with plasmonics), as well as the novel subdiffraction limit imaging techniques based on nonlinear behaviors of plasmonic scattering, is addressed.

  4. Nonlinear plasmonic imaging techniques and their biological applications

    Directory of Open Access Journals (Sweden)

    Deka Gitanjal

    2016-07-01

    Full Text Available Nonlinear optics, when combined with microscopy, is known to provide advantages including novel contrast, deep tissue observation, and minimal invasiveness. In addition, special nonlinearities, such as switch on/off and saturation, can enhance the spatial resolution below the diffraction limit, revolutionizing the field of optical microscopy. These nonlinear imaging techniques are extremely useful for biological studies on various scales from molecules to cells to tissues. Nevertheless, in most cases, nonlinear optical interaction requires strong illumination, typically at least gigawatts per square centimeter intensity. Such strong illumination can cause significant phototoxicity or even photodamage to fragile biological samples. Therefore, it is highly desirable to find mechanisms that allow the reduction of illumination intensity. Surface plasmon, which is the collective oscillation of electrons in metal under light excitation, is capable of significantly enhancing the local field around the metal nanostructures and thus boosting up the efficiency of nonlinear optical interactions of the surrounding materials or of the metal itself. In this mini-review, we discuss the recent progress of plasmonics in nonlinear optical microscopy with a special focus on biological applications. The advancement of nonlinear imaging modalities (including incoherent/coherent Raman scattering, two/three-photon luminescence, and second/third harmonic generations that have been amalgamated with plasmonics, as well as the novel subdiffraction limit imaging techniques based on nonlinear behaviors of plasmonic scattering, is addressed.

  5. CT enterography for Crohn's disease: optimal technique and imaging issues.

    Science.gov (United States)

    Baker, Mark E; Hara, Amy K; Platt, Joel F; Maglinte, Dean D T; Fletcher, Joel G

    2015-06-01

    CT enterography (CTE) is a common examination for patients with Crohn's disease. In order to achieve high quality, diagnostic images, proper technique is required. The purpose of this treatise is to review the processes and techniques that can optimize CTE for patients with suspected or known Crohn's disease. We will review the following: (1) how to start a CT enterography program; (2) workflow issues, including patient and ordering physician education and preparation; (3) oral contrast media options and administration regimens; (4) intravenous contrast media injection for uniphasic and multiphasic studies; (5) CTE radiation dose reduction strategies and the use of iterative reconstruction in lower dose examinations; (6) image reconstruction and interpretation; (7) imaging Crohn's patients in the acute or emergency department setting; (8) limitations of CTE as well as alternatives such as MRE or barium fluoroscopic examinations; and (9) dictation templates and a common nomenclature for reporting findings of CTE in Crohn's disease. Many of the issues discussed are summarized in the Abdominal Radiology Society Consensus MDCT Enterography Acquisition Protocol for Crohn's Disease.

  6. Kalman filter techniques for accelerated Cartesian dynamic cardiac imaging.

    Science.gov (United States)

    Feng, Xue; Salerno, Michael; Kramer, Christopher M; Meyer, Craig H

    2013-05-01

    In dynamic MRI, spatial and temporal parallel imaging can be exploited to reduce scan time. Real-time reconstruction enables immediate visualization during the scan. Commonly used view-sharing techniques suffer from limited temporal resolution, and many of the more advanced reconstruction methods are either retrospective, time-consuming, or both. A Kalman filter model capable of real-time reconstruction can be used to increase the spatial and temporal resolution in dynamic MRI reconstruction. The original study describing the use of the Kalman filter in dynamic MRI was limited to non-Cartesian trajectories because of a limitation intrinsic to the dynamic model used in that study. Here the limitation is overcome, and the model is applied to the more commonly used Cartesian trajectory with fast reconstruction. Furthermore, a combination of the Kalman filter model with Cartesian parallel imaging is presented to further increase the spatial and temporal resolution and signal-to-noise ratio. Simulations and experiments were conducted to demonstrate that the Kalman filter model can increase the temporal resolution of the image series compared with view-sharing techniques and decrease the spatial aliasing compared with TGRAPPA. The method requires relatively little computation, and thus is suitable for real-time reconstruction.

  7. Implementing Tumor Detection and Area Calculation in Mri Image of Human Brain Using Image Processing Techniques

    Directory of Open Access Journals (Sweden)

    Sunil L. Bangare

    2015-04-01

    Full Text Available This paper is based on the research on Human Brain Tumor which uses the MRI imaging technique to capture the image. In this proposed work Brain Tumor area is calculated to define the Stage or level of seriousness of the tumor. Image Processing techniques are used for the brain tumor area calculation and Neural Network algorithms for the tumor position calculation. Also in the further advancement the classification of the tumor based on few parameters is also expected. Proposed work is divided in to following Modules: Module 1: Image Pre-Processing Module 2: Feature Extraction, Segmentation using K-Means Algorithm and Fuzzy C-Means Algorithm Module 3: Tumor Area calculation & Stage detection Module 4: Classification and position calculation of tumor using Neural Network

  8. Automatic segmentation of blood vessels from retinal fundus images through image processing and data mining techniques

    Indian Academy of Sciences (India)

    R Geetharamani; Lakshmi Balasubramanian

    2015-09-01

    Machine Learning techniques have been useful in almost every field of concern. Data Mining, a branch of Machine Learning is one of the most extensively used techniques. The ever-increasing demands in the field of medicine are being addressed by computational approaches in which Big Data analysis, image processing and data mining are on top priority. These techniques have been exploited in the domain of ophthalmology for better retinal fundus image analysis. Blood vessels, one of the most significant retinal anatomical structures are analysed for diagnosis of many diseases like retinopathy, occlusion and many other vision threatening diseases. Vessel segmentation can also be a pre-processing step for segmentation of other retinal structures like optic disc, fovea, microneurysms, etc. In this paper, blood vessel segmentation is attempted through image processing and data mining techniques. The retinal blood vessels were segmented through color space conversion and color channel extraction, image pre-processing, Gabor filtering, image postprocessing, feature construction through application of principal component analysis, k-means clustering and first level classification using Naïve–Bayes classification algorithm and second level classification using C4.5 enhanced with bagging techniques. Association of every pixel against the feature vector necessitates Big Data analysis. The proposed methodology was evaluated on a publicly available database, STARE. The results reported 95.05% accuracy on entire dataset; however the accuracy was 95.20% on normal images and 94.89% on pathological images. A comparison of these results with the existing methodologies is also reported. This methodology can help ophthalmologists in better and faster analysis and hence early treatment to the patients.

  9. Imaging of Heterogeneous Materials with a Turbo Spin Echo Single-Point Imaging Technique

    Science.gov (United States)

    Beyea, Steven D.; Balcom, Bruce J.; Mastikhin, Igor V.; Bremner, Theodore W.; Armstrong, Robin L.; Grattan-Bellew, Patrick E.

    2000-06-01

    A magnetic resonance imaging method is presented for imaging of heterogeneous broad linewidth materials. This method allows for distortionless relaxation weighted imaging by obtaining multiple phase encoded k-space data points with each RF excitation pulse train. The use of this method, turbo spin echo single-point imaging-(turboSPI), leads to decreased imaging times compared to traditional constant-time imaging techniques, as well as the ability to introduce spin-spin relaxation contrast through the use of longer effective echo times. Imaging times in turboSPI are further decreased through the use of low flip angle steady-state excitation. Two-dimensional images of paramagnetic doped agarose phantoms were obtained, demonstrating the contrast and resolution characteristics of the sequence, and a method for both amplitude and phase deconvolution was demonstrated for use in high-resolution turboSPI imaging. Three-dimensional images of a partially water-saturated porous volcanic aggregate (T2L ≈ 200 ms, Δν1/2 ≈ 2500 Hz) contained in a hardened white Portland cement matrix (T2L ≈ 0.5 ms, Δν1/2 ≈ 2500 Hz) and a water-saturated quartz sand (T2 ≈ 300 ms, T2* ≈ 800 μs) are shown.

  10. The L_infinity constrained global optimal histogram equalization technique for real time imaging

    Science.gov (United States)

    Ren, Qiongwei; Niu, Yi; Liu, Lin; Jiao, Yang; Shi, Guangming

    2015-08-01

    Although the current imaging sensors can achieve 12 or higher precision, the current display devices and the commonly used digital image formats are still only 8 bits. This mismatch causes significant waste of the sensor precision and loss of information when storing and displaying the images. For better usage of the precision-budget, tone mapping operators have to be used to map the high-precision data into low-precision digital images adaptively. In this paper, the classic histogram equalization tone mapping operator is reexamined in the sense of optimization. We point out that the traditional histogram equalization technique and its variants are fundamentally improper by suffering from local optimum problems. To overcome this drawback, we remodel the histogram equalization tone mapping task based on graphic theory which achieves the global optimal solutions. Another advantage of the graphic-based modeling is that the tone-continuity is also modeled as a vital constraint in our approach which suppress the annoying boundary artifacts of the traditional approaches. In addition, we propose a novel dynamic programming technique to solve the histogram equalization problem in real time. Experimental results shows that the proposed tone-preserved global optimal histogram equalization technique outperforms the traditional approaches by exhibiting more subtle details in the foreground while preserving the smoothness of the background.

  11. Imaging techniques for ultrasonic testing; Bildgebende Verfahren fuer die Ultraschallpruefung

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    These seminar proceedings contain 16 lectures on the following topics: 1. From imaging to quantification - ultrasound methods in medical diagnostics; 2. SAFT, TOFD, Phased Array - classical applications and recent developments in ultrasonic imaging; 3. Innovative ultrasonic imaging methods in research and application; 4. Industrial ultrasonic testing of fibre-reinforced structures of complex geometry; 5. Visualisation of crack tips in the inspection of wheel set shafts with longitudinal boreholes as a means of avoiding unnecessary wheel set changes; 6. Areal analysis of the propagation of Lamb waves on curved, anisotropic structures; 7. High-resolution representation in immersion technique testing; 8. Variants in generating images from phased array measurement data - practical examples involving copper, carbon-fibre reinforced plastic and other materials; 9. GIUM - an unconventional method of microstructure imaging using ultrasonic stimulation and laser vibrometry scanning; 10. Innovative air-ultrasonic testing concepts for improved imaging; 11. Use of imaging methods for improving the quality of test results from nondestructive testing; 12. Modelling and visualisation of EMUS stimulation for transducer optimisation; 13. Use of SAFT in the manufacture of energy conversion machines; 14. Ultrasonic imaging tests for improved defect characterisation during weld seam inspection on longitudinally welded large-diameter pipes; 15. SAFT reconstruction for testing austenitic weld seams and dissimilar metal weld seams for transverse cracks; 16. Imaging-based optimisation method for quantitative ultrasonic testing of anisotropic inhomogeneous austenitic welded joints with determination and utilisation of their elastic properties. One contribution has been abstracted separately. [German] Dieser Seminarband enthaelt 16 Vortraege mit folgenden Themen: 1. Von der Bildgebung bis zur Quantifizierung - Ultraschallverfahren in der medizinischen Diagnostik; 2. SAFT, TOFD, Phased Array

  12. Minimally invasive surgery of diabetic foot – review of current techniques

    Science.gov (United States)

    I, Botezatu; D, Laptoiu

    2016-01-01

    The term diabetic foot is usually used to indicate advanced foot pathology (complex clinical situations correlating diabetic foot ulcers, diabetic foot infections, Charcot foot, and critical limb ischemia). The early recognition of the etiology of these foot lesions is essential for the therapeutic decision in order to achieve a good functional result. Several surgical procedures involving the foot have been developed in order to promote healing and avoid complications. Traditionally, surgery has been performed in an open way. The literature regarding the performance and efficacy of classical osteotomies and arthrodesis is inconsistent. This can be attributed to several variables, such as differences in patient clinical aspects and the panel of surgical techniques utilized. As with other surgical specialties, fluoroscopic imaging and minimally invasive tools are now being incorporated in these procedures. The use of high speed burrs associated with specialized osteosynthesis implants, offers several advantages over classical techniques. The ability to associate these gestures to complex protocols is beginning to be currently developed. The respect for the soft tissues is considered one of the first advantages. Despite the limited time since they were introduced in clinical practice, functional results seemed to be consistent, supporting the use of this technology. PMID:27974928

  13. Nanoscale Imaging of Current Density with a Single-Spin Magnetometer.

    Science.gov (United States)

    Chang, K; Eichler, A; Rhensius, J; Lorenzelli, L; Degen, C L

    2017-03-24

    Charge transport in nanostructures and thin films is fundamental to many phenomena and processes in science and technology, ranging from quantum effects and electronic correlations in mesoscopic physics, to integrated charge- or spin-based electronic circuits, to photoactive layers in energy research. Direct visualization of the charge flow in such structures is challenging due to their nanometer size and the itinerant nature of currents. In this work, we demonstrate noninvasive magnetic imaging of current density in two-dimensional conductor networks including metallic nanowires and carbon nanotubes. Our sensor is the electronic spin of a diamond nitrogen-vacancy center attached to a scanning tip and operated under ambient conditions. Using a differential measurement technique, we detect DC currents down to a few μA with a current density noise floor of ∼2 × 10(4) A/cm(2). Reconstructed images have a spatial resolution of typically 50 nm, with a best-effort value of 22 nm. Current density imaging offers a new route for studying electronic transport and conductance variations in two-dimensional materials and devices, with many exciting applications in condensed matter physics and materials science.

  14. EFFICIENT RETRIEVAL TECHNIQUES FOR IMAGES USING ENHANCED UNIVARIATE TRANSFORMATION APPROACH

    OpenAIRE

    DR.S.P.VICTOR,; MRS.V.NARAYANI,; S. Rajkumar

    2010-01-01

    Image mining is a process to find valid, useful, and understandable knowledge from large image sets or image databases. Image mining combines the areas of content-based image retrieval, image understanding, data mining and databases. Image mining deals with the extraction of knowledge, image data relationship, or other patterns not explicitly stored in the images. It uses methods from computer vision, image processing, image retrieval, data mining, machine learning, database, and artificial i...

  15. Novel endoscopic imaging techniques toward in vivo observation of living cancer cells in the gastrointestinal tract.

    Science.gov (United States)

    Inoue, Haruhiro; Kudo, Shin-ei; Shiokawa, Akira

    2005-07-01

    It is now possible to perform microscopic imaging of living cells from both normal mucosa and malignant tissue in the gastrointestinal tract. Endocytoscopy is a catheter-type contact endoscope that has more than 1000-fold magnifying power and can pass through the working channel of the straight-view endoscope. In esophageal cells, the nucleus, cell body, and even the nucleolus were clearly distinguished with high-resolution images comparable with those of conventional cytology. This novel technology has the potential to provide histologic diagnoses during endoscopic examinations, similar to those obtained currently by conventional histology techniques.

  16. The role of functional imaging techniques in the dementia

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Young Hoon [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2004-06-01

    Evaluation of dementia in patients with early symptoms of cognitive decline is clinically challenging, but the need for early, accurate diagnosis has become more crucial, since several medication for the treatment of mild to moderate Alzheimer' disease are available. Many neurodegenerative diseases produce significant brain function alteration even when structural imaging (CT of MRI) reveal no specific abnormalities. The role of PET and SPECT brain imaging in the initial assessment and differential diagnosis of dementia is beginning to evolve rapidly and growing evidence indicates that appropriate incorporation of PET into the clinical work up can improve diagnostic and prognostic accuracy with respect to Alzheimer's disease, the most common cause of dementia in the geriatric population. In the fast few years, studies comparing neuropathologic examination with PET have established reliable and consistent accuracy for diagnostic evaluations using PET - accuracies substantially exceeding those of comparable studies of diagnostic value of SPECT or of both modalities assessed side by side, or of clinical evaluations done without nuclear imaging. This review deals the role of functional brian imaging techniques in the evaluation of dementias and the role of nuclear neuroimaging in the early detection and diagnosis of Alzheimer's disease.

  17. A laser speckle imaging technique for measuring tissue perfusion.

    Science.gov (United States)

    Forrester, Kevin R; Tulip, J; Leonard, C; Stewart, C; Bray, Robert C

    2004-11-01

    Laser Doppler imaging (LDI) has become a standard method for optical measurement of tissue perfusion, but is limited by low resolution and long measurement times. We have developed an analysis technique based on a laser speckle imaging method that generates rapid, high-resolution perfusion images. We have called it laser speckle perfusion imaging (LSPI). This paper investigates LSPI output and compares it to LDI using blood flow models designed to simulate human skin at various levels of pigmentation. Results show that LSPI parameters can be chosen such that the instrumentation exhibits a similar response to changes in red blood cell concentration (0.1%-5%, 200 microL/min) and velocity (0-800 microL/min, 1% concentration) and, given its higher resolution and quicker response time, could provide a significant advantage over LDI for some applications. Differences were observed in the LDI and LSPI response to tissue optical properties. LDI perfusion values increased with increasing tissue absorption, while LSPI perfusion values showed a slight decrease. This dependence is predictable, owing to the perfusion algorithms specific to each instrument, and, if properly compensated for, should not influence each instrument's ability to measure relative changes in tissue perfusion.

  18. Monitoring Therapeutic Treatments against Burkholderia Infections Using Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Tiffany M. Mott

    2013-05-01

    Full Text Available Burkholderia mallei, the etiologic agent of glanders, are Category B select agents with biothreat potential, and yet effective therapeutic treatments are lacking. In this study, we showed that CpG administration increased survival, demonstrating protection in the murine glanders model. Bacterial recovery from infected lungs, liver and spleen was significantly reduced in CpG-treated animals as compared with non-treated mice. Reciprocally, lungs of CpG-treated infected animals were infiltrated with higher levels of neutrophils and inflammatory monocytes, as compared to control animals. Employing the B. mallei bioluminescent strain CSM001 and the Neutrophil-Specific Fluorescent Imaging Agent, bacterial dissemination and neutrophil trafficking were monitored in real-time using multimodal in vivo whole body imaging techniques. CpG-treatment increased recruitment of neutrophils to the lungs and reduced bioluminescent bacteria, correlating with decreased bacterial burden and increased protection against acute murine glanders. Our results indicate that protection of CpG-treated animals was associated with recruitment of neutrophils prior to infection and demonstrated, for the first time, simultaneous real time in vivo imaging of neutrophils and bacteria. This study provides experimental evidence supporting the importance of incorporating optimized in vivo imaging methods to monitor disease progression and to evaluate the efficacy of therapeutic treatment during bacterial infections.

  19. Surveying and benchmarking techniques to analyse DNA gel fingerprint images.

    Science.gov (United States)

    Heras, Jónathan; Domínguez, César; Mata, Eloy; Pascual, Vico

    2016-11-01

    DNA fingerprinting is a genetic typing technique that allows the analysis of the genomic relatedness between samples, and the comparison of DNA patterns. The analysis of DNA gel fingerprint images usually consists of five consecutive steps: image pre-processing, lane segmentation, band detection, normalization and fingerprint comparison. In this article, we firstly survey the main methods that have been applied in the literature in each of these stages. Secondly, we focus on lane-segmentation and band-detection algorithms-as they are the steps that usually require user-intervention-and detect the seven core algorithms used for both tasks. Subsequently, we present a benchmark that includes a data set of images, the gold standards associated with those images and the tools to measure the performance of lane-segmentation and band-detection algorithms. Finally, we implement the core algorithms used both for lane segmentation and band detection, and evaluate their performance using our benchmark. As a conclusion of that study, we obtain that the average profile algorithm is the best starting point for lane segmentation and band detection.

  20. Magnetic resonance imaging urodynamics: technique development and preliminary results

    Directory of Open Access Journals (Sweden)

    Gustavo Borghesi

    2006-06-01

    Full Text Available OBJECTIVES: In this preliminary study we report the development of the video urodynamic technique using magnetic resonance imaging (MRI. MATERIALS AND METHODS: We studied 6 women with genuine stress urinary incontinence, diagnosed by history and physical examination. Urodynamic examination was performed on multichannel equipment with the patient in the supine position. Coughing and Valsalva maneuvers were performed at volumes of 150, 250 and 350 mL. Simultaneously, MRI was carried out by using 1.5 T GE Signa CV/i high-speed scanner with real time fluoroscopic imaging possibilities. Fluoroscopic imaging was accomplished in the corresponding planes with T2-weighted single shot fast spin echo sequences at a speed of about 1 frame per second. Both studies were recorded and synchronized, resulting in a single video urodynamic examination. RESULTS: Dynamic MRI with cine-loop reconstruction of 1 image per second demonstrated the movement of all compartment of the relaxed pelvis during straining with the concomitant registration of abdominal and intravesical pressures. In 5 patients, urinary leakage was demonstrated during straining and the Valsalva leak point pressure (VLPP was determined as the vesical pressure at leak subtracted from baseline bladder pressure. Mean VLPP was 72.6 cm H2O (ranging from 43 to 122 cm H2O. CONCLUSIONS: The concept of MRI video urodynamics is feasible. In a clinical perspective, practical aspects represent a barrier to daily use and it should be recommended for research purposes.

  1. Automated Coronal Loop Identification Using Digital Image Processing Techniques

    Science.gov (United States)

    Lee, Jong K.; Gary, G. Allen; Newman, Timothy S.

    2003-01-01

    The results of a master thesis project on a study of computer algorithms for automatic identification of optical-thin, 3-dimensional solar coronal loop centers from extreme ultraviolet and X-ray 2-dimensional images will be presented. These center splines are proxies of associated magnetic field lines. The project is pattern recognition problems in which there are no unique shapes or edges and in which photon and detector noise heavily influence the images. The study explores extraction techniques using: (1) linear feature recognition of local patterns (related to the inertia-tensor concept), (2) parametric space via the Hough transform, and (3) topological adaptive contours (snakes) that constrains curvature and continuity as possible candidates for digital loop detection schemes. We have developed synthesized images for the coronal loops to test the various loop identification algorithms. Since the topology of these solar features is dominated by the magnetic field structure, a first-order magnetic field approximation using multiple dipoles provides a priori information in the identification process. Results from both synthesized and solar images will be presented.

  2. Current knowledge and importance of dGEMRIC techniques in diagnosis of hip joint diseases

    Energy Technology Data Exchange (ETDEWEB)

    Zilkens, Christoph; Krauspe, Ruediger; Bittersohl, Bernd [University of Duesseldorf, Medical Faculty, Department of Orthopedic Surgery, Duesseldorf (Germany); Tiderius, Carl Johann [Lund University Hospital, Department of Orthopedic Surgery, Lund (Sweden)

    2015-08-15

    Accurate assessment of early hip joint cartilage alterations may help optimize patient selection and follow-up of hip joint preservation surgery. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is sensitive to the glycosaminoglycan content in cartilage that is lost early in the development of osteoarthritis (OA). Hence, the dGEMRIC technique holds promise for the development of new diagnostic and therapeutic procedures. However, because of the location of the hip joint deep within the body and due to the fairly thin cartilage layers that require high spatial resolution, the diagnosis of early hip joint cartilage alterations may be problematic. The purpose of this review is to outline the current status of dGEMRIC in the assessment of hip joint cartilage. A literature search was performed with PubMed, using the terms ''cartilage, osteoarthritis, hip joint, MRI, and dGEMRIC'', considering all levels of studies. This review revealed that dGEMRIC can be reliably used in the evaluation of early stage cartilage pathology in various hip joint disorders. Modifications in the technique, such as the operation of three-dimensional imaging and dGEMRIC after intra-articular contrast medium administration, have expanded the range of application. Notably, the studies differ considerably in patient selection and technical prerequisites. Furthermore, there is a need for multicenter prospective studies with the required technical conditions in place to establish outcome based dGEMRIC data to obtain, in conjunction with clinical data, reliable threshold values for normal and abnormal cartilage, and for hips that may benefit from conservative or surgical treatment. (orig.)

  3. BaTMAn: Bayesian Technique for Multi-image Analysis

    Science.gov (United States)

    Casado, J.; Ascasibar, Y.; García-Benito, R.; Guidi, G.; Choudhury, O. S.; Bellocchi, E.; Sánchez, S. F.; Díaz, A. I.

    2016-12-01

    Bayesian Technique for Multi-image Analysis (BaTMAn) characterizes any astronomical dataset containing spatial information and performs a tessellation based on the measurements and errors provided as input. The algorithm iteratively merges spatial elements as long as they are statistically consistent with carrying the same information (i.e. identical signal within the errors). The output segmentations successfully adapt to the underlying spatial structure, regardless of its morphology and/or the statistical properties of the noise. BaTMAn identifies (and keeps) all the statistically-significant information contained in the input multi-image (e.g. an IFS datacube). The main aim of the algorithm is to characterize spatially-resolved data prior to their analysis.

  4. Free Radical Imaging Techniques Applied to Hydrocarbon Flames Diagnosis

    Institute of Scientific and Technical Information of China (English)

    A. Caldeira-Pires

    2001-01-01

    This paper evaluates the utilization of free radical chemiluminescence imaging and tomographic reconstruction techniques to assess advanced information on reacting flows. Two different laboratory flow configurations were analyzed, including unconfined non-premixed jet flame measurements to evaluate flame fuel/air mixing patterns at the burner-port of a typical glass-furnace burner. The second case characterized the reaction zone of premixed flames within gas turbine combustion chambers, based on a laboratory scale model of a lean prevaporized premixed (LPP) combustion chamber.The analysis shows that advanced imaging diagnosis can provide new information on the characterization of flame mixing and reacting phenomena. The utilization of local C2 and CH chemiluminescence can assess useful information on the quality of the combustion process, which can be used to improve the design of practical combustors.

  5. Two-dimensional Imaging Velocity Interferometry: Technique and Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D J; Smith, R F; Bolme, C; Celliers, P; Collins, G

    2011-03-23

    We describe the data analysis procedures for an emerging interferometric technique for measuring motion across a two-dimensional image at a moment in time, i.e. a snapshot 2d-VISAR. Velocity interferometers (VISAR) measuring target motion to high precision have been an important diagnostic in shockwave physics for many years Until recently, this diagnostic has been limited to measuring motion at points or lines across a target. We introduce an emerging interferometric technique for measuring motion across a two-dimensional image, which could be called a snapshot 2d-VISAR. If a sufficiently fast movie camera technology existed, it could be placed behind a traditional VISAR optical system and record a 2d image vs time. But since that technology is not yet available, we use a CCD detector to record a single 2d image, with the pulsed nature of the illumination providing the time resolution. Consequently, since we are using pulsed illumination having a coherence length shorter than the VISAR interferometer delay ({approx}0.1 ns), we must use the white light velocimetry configuration to produce fringes with significant visibility. In this scheme, two interferometers (illuminating, detecting) having nearly identical delays are used in series, with one before the target and one after. This produces fringes with at most 50% visibility, but otherwise has the same fringe shift per target motion of a traditional VISAR. The 2d-VISAR observes a new world of information about shock behavior not readily accessible by traditional point or 1d-VISARS, simultaneously providing both a velocity map and an 'ordinary' snapshot photograph of the target. The 2d-VISAR has been used to observe nonuniformities in NIF related targets (polycrystalline diamond, Be), and in Si and Al.

  6. Electrooptical Evaluation Techniques of Image Intensifier 'Ibbes - Part I

    Directory of Open Access Journals (Sweden)

    I. J. Bhasin

    2004-04-01

    Full Text Available Passive night vision devices are used for viewing the military targets at low light levels of illuminations during night. In these passive night vision devices, image intensifier tubes areused to amplify scene imagery. The performance of these tubes depends upon electrooptical parameters. The techniques of evaluating these parameters, eg, luminous gain, automatic rightness control and maximum screen luminance, photocathode sensitivity, radiant gain, equivalent background illumination, magnification and distortion, signal-to-noise ratio, veilingglare, screen brightness variation, etc. have been described.

  7. Automatic identification of corrosion damage using image processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bento, Mariana P.; Ramalho, Geraldo L.B.; Medeiros, Fatima N.S. de; Ribeiro, Elvis S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Medeiros, Luiz C.L. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This paper proposes a Nondestructive Evaluation (NDE) method for atmospheric corrosion detection on metallic surfaces using digital images. In this study, the uniform corrosion is characterized by texture attributes extracted from co-occurrence matrix and the Self Organizing Mapping (SOM) clustering algorithm. We present a technique for automatic inspection of oil and gas storage tanks and pipelines of petrochemical industries without disturbing their properties and performance. Experimental results are promising and encourage the possibility of using this methodology in designing trustful and robust early failure detection systems. (author)

  8. Investigation of ion-atom collision dynamics through imaging techniques

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The principle and technique details of recoil ion momentum imaging are discussed and summarized. The recoil ion momentum spectroscopy built at the Institute of Modern Physics (Lanzhou) is presented. The first results obtained at the setup are analyzed. For 30 keV He2+ on He collision, it is found that the capture of single electron occurs dominantly into the first excited states, and the related scattering angle results show that the ground state capture occurs at large impact parameters, while the capture into excited states occurs at small impact parameters. The results manifest the collision dynamics for the sub-femto-second process can be studied through the techniques uniquely. Finally, the future possibilities of applications of the recoil ion momentum spectroscopy in other fields are outlined.

  9. Lunar Imaging and Ionospheric Calibration for the Lunar Cherenkov Technique

    CERN Document Server

    McFadden, Rebecca; Mevius, Maaijke

    2013-01-01

    The Lunar Cherenkov technique is a promising method for UHE neutrino and cosmic ray detection which aims to detect nanosecond radio pulses produced during particle interactions in the Lunar regolith. For low frequency experiments, such as NuMoon, the frequency dependent dispersive effect of the ionosphere is an important experimental concern as it reduces the pulse amplitude and subsequent chances of detection. We are continuing to investigate a new method to calibrate the dispersive effect of the ionosphere on lunar Cherenkov pulses via Faraday rotation measurements of the Moon's polarised emission combined with geomagnetic field models. We also extend this work to include radio imaging of the Lunar surface, which provides information on the physical and chemical properties of the lunar surface that may affect experimental strategies for the lunar Cherenkov technique.

  10. An Introduction of Image Steganographic Techniques and Comparison

    Directory of Open Access Journals (Sweden)

    Ravi kumar

    2012-06-01

    Full Text Available as a society, humans have continually sought new and efficient ways to communicate. The earliest methods included cave drawings, smoke signals, and drums. Advancements of civilization introduced written language, telegraph, radio/television, and most recently electronic mail. As more and more communication is conducted electronically, new needs, issues, and opportunities are born. Steganography can be used to hide or cover the existence of communication. Steganography is not a new science. Some of the first documented examples of steganography can be found in the Histories of Herodotus, where the father of history relates several stories from the times of ancient Greece. This paper intends to give an overview of image Steganography, its uses and techniques. It also attempts to identify the requirements of a good steganographic algorithm and briefly reflects on which steganographic techniques are more suitable for which applications.

  11. Functional imaging and related techniques: An introduction for rehabilitation researchers

    Directory of Open Access Journals (Sweden)

    Bruce Crosson, PhD

    2010-04-01

    Full Text Available Over the past 25 years, techniques to image brain structure and function have offered investigators in the cognitive neurosciences and related fields unprecedented opportunities to study how human brain systems work and are connected. Indeed, the number of peer-reviewed research articles using these techniques has grown at an exponential rate during this period. Inevitably, investigators have become interested in mapping neuroplastic changes that support learning and memory using functional neuroimaging, and concomitantly, rehabilitation researchers have become interested in mapping changes in brain systems responsible for treatment effects during the rehabilitation of patients with stroke, traumatic brain injury, and other brain injury or disease. This new rehabilitation research and development arena is important because a greater understanding of how and why brain systems remap in the service of rehabilitation will lead to the development of better treatments.

  12. Activated sludge characterization through microscopy: A review on quantitative image analysis and chemometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Daniela P. [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Amaral, A. Luís [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra (Portugal); Ferreira, Eugénio C., E-mail: ecferreira@deb.uminho.pt [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2013-11-13

    Graphical abstract: -- Highlights: •Quantitative image analysis shows potential to monitor activated sludge systems. •Staining techniques increase the potential for detection of operational problems. •Chemometrics combined with quantitative image analysis is valuable for process monitoring. -- Abstract: In wastewater treatment processes, and particularly in activated sludge systems, efficiency is quite dependent on the operating conditions, and a number of problems may arise due to sludge structure and proliferation of specific microorganisms. In fact, bacterial communities and protozoa identification by microscopy inspection is already routinely employed in a considerable number of cases. Furthermore, quantitative image analysis techniques have been increasingly used throughout the years for the assessment of aggregates and filamentous bacteria properties. These procedures are able to provide an ever growing amount of data for wastewater treatment processes in which chemometric techniques can be a valuable tool. However, the determination of microbial communities’ properties remains a current challenge in spite of the great diversity of microscopy techniques applied. In this review, activated sludge characterization is discussed highlighting the aggregates structure and filamentous bacteria determination by image analysis on bright-field, phase-contrast, and fluorescence microscopy. An in-depth analysis is performed to summarize the many new findings that have been obtained, and future developments for these biological processes are further discussed.

  13. Reliable and robust transmission and storage techniques for medical images with patient information.

    Science.gov (United States)

    Nergui, Myagmarbayar; Acharya, U Sripati; Acharya U, Rajendra; Yu, Wenwei

    2010-12-01

    There is an increased emphasis on the use of digital techniques in all aspects of human life today. Broadcast radio and television, cellular phone services, consumer and entertainment electronics etc are increasingly using digital signal processing techniques to improve the quality of service. Transmission and storage of documentation and images pertaining to patient records cannot remain an exception to this global trend. Hence, patient records (text and image information) are increasingly stored and processed in digital form. Currently, text and image information, which constitute two separate pieces of data are handled as different files. Thus, there is a possibility of the text and message information, pertaining to different patients, being interchanged and thus mishandled. This can be avoided by merging text and image information in such a manner that the two can be separated without perceptible damage to information contained in either file. Digital watermarking techniques can be used to interleave patient information with medical images. In this work, we have employed digital watermarking along with strong cryptographic protocols and powerful error correcting codes. This reduces the probability of sensitive patient information falling into the wrong hands and ensures information integrity when it is conveyed over noisy channels.

  14. The maturing of high contrast imaging and starlight suppression techniques for future NASA exoplanet characterization missions

    Science.gov (United States)

    Coulter, Daniel R.; Gallagher, David B.; Siegler, Nicholas; Shaklan, Stuart; Stapelfeldt, Karl; Traub, Wesley A.

    2016-07-01

    Over 3000 exoplanets and hundreds of exoplanetary systems have been detected to date and we are now rapidly moving toward an era where the focus is shifting from detection to direct imaging and spectroscopic characterization of these new worlds and their atmospheres. NASA is currently studying several exoplanet characterization mission concepts for the 2020 Decadal Survey ranging from probe class to flagships. Detailed and comprehensive exoplanet characterization, particularly of exo-Earths, leading to assessment of habitability, or indeed detection of life, will require significant advances beyond the current state-of-the-art in high contrast imaging and starlight suppression techniques which utilize specially shaped precision optical elements to block the light from the parent star while controlling scattering and diffraction thus revealing and enabling spectroscopic study of the orbiting exoplanets in reflected light. In this paper we describe the two primary high contrast starlight suppression techniques currently being pursued by NASA: 1) coronagraphs (including several design variations) and 2) free-flying starshades. These techniques are rapidly moving from the technology development phase to the design and engineering phase and we discuss the prospects and projected performance for future exoplanet characterization missions utilizing these techniques coupled with large aperture telescopes in space.

  15. STUDY OF IMAGE SEGMENTATION TECHNIQUES ON RETINAL IMAGES FOR HEALTH CARE MANAGEMENT WITH FAST COMPUTING

    Directory of Open Access Journals (Sweden)

    Srikanth Prabhu

    2012-02-01

    Full Text Available The role of segmentation in image processing is to separate foreground from background. In this process, the features become clearly visible when appropriate filters are applied on the image. In this paper emphasis has been laid on segmentation of biometric retinal images to filter out the vessels explicitly for evaluating the bifurcation points and features for diabetic retinopathy. Segmentation on images is performed by calculating ridges or morphology. Ridges are those areas in the images where there is sharp contrast in features. Morphology targets the features using structuring elements. Structuring elements are of different shapes like disk, line which is used for extracting features of those shapes. When segmentation was performed on retinal images problems were encountered during image pre-processing stage. Also edge detection techniques have been deployed to find out the contours of the retinal images. After the segmentation has been performed, it has been seen that artifacts of the retinal images have been minimal when ridge based segmentation technique was deployed. In the field of Health Care Management, image segmentation has an important role to play as it determines whether a person is normal or having any disease specially diabetes. During the process of segmentation, diseased features are classified as diseased one’s or artifacts. The problem comes when artifacts are classified as diseased ones. This results in misclassification which has been discussed in the analysis Section. We have achieved fast computing with better performance, in terms of speed for non-repeating features, when compared to repeating features.

  16. Automatic DNA Diagnosis for 1D Gel Electrophoresis Images using Bio-image Processing Technique.

    Science.gov (United States)

    Intarapanich, Apichart; Kaewkamnerd, Saowaluck; Shaw, Philip J; Ukosakit, Kittipat; Tragoonrung, Somvong; Tongsima, Sissades

    2015-01-01

    DNA gel electrophoresis is a molecular biology technique for separating different sizes of DNA fragments. Applications of DNA gel electrophoresis include DNA fingerprinting (genetic diagnosis), size estimation of DNA, and DNA separation for Southern blotting. Accurate interpretation of DNA banding patterns from electrophoretic images can be laborious and error prone when a large number of bands are interrogated manually. Although many bio-imaging techniques have been proposed, none of them can fully automate the typing of DNA owing to the complexities of migration patterns typically obtained. We developed an image-processing tool that automatically calls genotypes from DNA gel electrophoresis images. The image processing workflow comprises three main steps: 1) lane segmentation, 2) extraction of DNA bands and 3) band genotyping classification. The tool was originally intended to facilitate large-scale genotyping analysis of sugarcane cultivars. We tested the proposed tool on 10 gel images (433 cultivars) obtained from polyacrylamide gel electrophoresis (PAGE) of PCR amplicons for detecting intron length polymorphisms (ILP) on one locus of the sugarcanes. These gel images demonstrated many challenges in automated lane/band segmentation in image processing including lane distortion, band deformity, high degree of noise in the background, and bands that are very close together (doublets). Using the proposed bio-imaging workflow, lanes and DNA bands contained within are properly segmented, even for adjacent bands with aberrant migration that cannot be separated by conventional techniques. The software, called GELect, automatically performs genotype calling on each lane by comparing with an all-banding reference, which was created by clustering the existing bands into the non-redundant set of reference bands. The automated genotype calling results were verified by independent manual typing by molecular biologists. This work presents an automated genotyping tool from DNA

  17. Magnetic resonance imaging in psoriatic arthritis -- update on current status and future perspectives

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Poggenborg, René Panduro

    2012-01-01

    Measures in Rheumatology) may contribute to facilitating research, identifying appropriate areas for use, and reaching consensus on the optimal examination technique. Accordingly, GRAPPA, a primary driver of international research in psoriasis and psoriatic arthritis (PsA), has focused on the current use......The potential of magnetic resonance imaging (MRI) for use in clinical practice and research has gained increasing interest over the last decade. International collaborative initiatives from GRAPPA (Group for Research and Assessment of Psoriasis and Psoriatic Arthritis) and/or OMERACT (Outcome...... and future development of MRI and other modern imaging modalities in PsA. This review, presented at the GRAPPA 2010 annual meeting, describes the current status of MRI in PsA, with a focus on its use in diagnosis, monitoring, and prediction of the disease course and treatment response. Important areas...

  18. Amide proton transfer imaging in clinics: Basic concepts and current and future use in brain tumors and stoke

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Eun [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Jahng, Geon Ho [Dept. of Radiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Jeong, Ha Kyu [Philips Korea, Seoul (Korea, Republic of)

    2016-12-15

    Amide proton transfer (APT) imaging is gaining attention as a relatively new in vivo molecular imaging technique that has higher sensitivity and spatial resolution than magnetic resonance spectroscopy imaging. APT imaging is a subset of the chemical exchange saturation transfer mechanism, which can offer unique image contrast by selectively saturating protons in target molecules that get exchanged with protons in bulk water. In this review, we describe the basic concepts of APT imaging, particularly with regard to the benefit in clinics from the current literature. Clinical applications of APT imaging are described from two perspectives: in the diagnosis and monitoring of the treatment response in brain glioma by reflecting endogenous mobile proteins and peptides, and in the potential for stroke imaging with respect to tissue acidity.

  19. Short-circuit current density imaging of crystalline silicon solar cells via lock-in thermography: Robustness and simplifications

    Energy Technology Data Exchange (ETDEWEB)

    Fertig, Fabian, E-mail: fabian.fertig@ise.fraunhofer.de; Greulich, Johannes; Rein, Stefan [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, D-79110 Freiburg (Germany)

    2014-11-14

    Spatially resolved determination of solar cell parameters is beneficial for loss analysis and optimization of conversion efficiency. One key parameter that has been challenging to access by an imaging technique on solar cell level is short-circuit current density. This work discusses the robustness of a recently suggested approach to determine short-circuit current density spatially resolved based on a series of lock-in thermography images and options for a simplified image acquisition procedure. For an accurate result, one or two emissivity-corrected illuminated lock-in thermography images and one dark lock-in thermography image have to be recorded. The dark lock-in thermography image can be omitted if local shunts are negligible. Furthermore, it is shown that omitting the correction of lock-in thermography images for local emissivity variations only leads to minor distortions for standard silicon solar cells. Hence, adequate acquisition of one image only is sufficient to generate a meaningful map of short-circuit current density. Beyond that, this work illustrates the underlying physics of the recently proposed method and demonstrates its robustness concerning varying excitation conditions and locally increased series resistance. Experimentally gained short-circuit current density images are validated for monochromatic illumination in comparison to the reference method of light-beam induced current.

  20. Performance evaluation of image enhancement techniques on a digital image-intensifier

    NARCIS (Netherlands)

    Dijk, J.; Bijl, P.; Bouma, H.

    2009-01-01

    Recently new techniques for night-vision cameras are developed. Digital image-intensifiers are becoming available on the market. Also, so-called EMCCD cameras are developed, which may even be able to record color information about the scene. However, in low-light situations all night-vision imagery

  1. A new imaging technique for detecting interstellar communications

    Science.gov (United States)

    Vallerga, John; Welsh, Barry; Kotze, Marissa; Siegmund, Oswald

    2017-01-01

    We report on a unique detection methodology using the Berkeley Visible Image Tube (BVIT) mounted on the 10m Southern African Large Telescope (SALT) to search for laser pulses originating in communications from advanced extraterrestrial (ET) civilizations residing on nearby Earth-like planets located within their habitability zones. The detection technique assumes that ET communicates through high powered pulsed lasers with pulse durations on the order of 5 nanoseconds, the signals thereby being brighter than that of the host star within this very short period of time. Our technique turns down the gain of the optically sensitive photon counting microchannel plate detector such that ~30 photons are required in a 5ns window to generate an imaged event. Picking a priori targets with planets in the habitable zone substantially reduces the false alarm rate. Interplanetary communication by optical masers was first postulated by Schwartz and Townes in 1961. Under the assumption that ET has access to a 10 m class telescope operated as a transmitter then we could detect lasers with a similar power to that of the Livermore Laboratory laser (~1.8Mj per pulse), to a distance of ~ 1000 pc. In this talk we present the results of 2400 seconds of BVIT observations on the SALT of the star Wolf 1061, which is known to harbor an Earth-sized exoplanet located in the habitability zone. At this distance (4.3 pc), BVIT on SALT could detect a 48 joule per pulse laser, now commercially available as tabletop devices.

  2. A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging.

    Science.gov (United States)

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-06-01

    The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR = 20. For

  3. Magnetostatic image current and its application to an analytic identification of a current dipole inside a conducting sphere.

    Science.gov (United States)

    He, S; Norgren, M

    2000-02-01

    The image solution for the static magnetic field outside a conducting sphere with an internal current dipole is considered. The image current, which is a linear distribution of magnetic dipoles on the line segment between the dipole point and the center of the sphere, is derived by using the fact that the induced current does not have any contribution to the radial component of the magnetic field outside the sphere. The image is then used to obtain some explicit formulas for identifying the location and tangential moment of the primary current dipole. This explicit identification method is also tested with a real model for a patient's brain.

  4. Update: Cardiac Imaging (II). Transcatheter Aortic Valve Replacement: Advantages and Limitations of Different Cardiac Imaging Techniques.

    Science.gov (United States)

    Podlesnikar, Tomaz; Delgado, Victoria

    2016-03-01

    Transcatheter aortic valve replacement is an established therapy for patients with symptomatic severe aortic stenosis and contraindications or high risk for surgery. Advances in prostheses and delivery system designs and continuous advances in multimodality imaging, particularly the 3-dimensional techniques, have led to improved outcomes with significant reductions in the incidence of frequent complications such as paravalvular aortic regurgitation. In addition, data on prosthesis durability are accumulating. Multimodality imaging plays a central role in the selection of patients who are candidates for transcatheter aortic valve replacement, procedure planning and guidance, and follow-up of prosthesis function. The strengths and limitations of each imaging technique for transcatheter aortic valve replacement will be discussed in this update article. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Distributed Source Coding Techniques for Lossless Compression of Hyperspectral Images

    Directory of Open Access Journals (Sweden)

    Barni Mauro

    2007-01-01

    Full Text Available This paper deals with the application of distributed source coding (DSC theory to remote sensing image compression. Although DSC exhibits a significant potential in many application fields, up till now the results obtained on real signals fall short of the theoretical bounds, and often impose additional system-level constraints. The objective of this paper is to assess the potential of DSC for lossless image compression carried out onboard a remote platform. We first provide a brief overview of DSC of correlated information sources. We then focus on onboard lossless image compression, and apply DSC techniques in order to reduce the complexity of the onboard encoder, at the expense of the decoder's, by exploiting the correlation of different bands of a hyperspectral dataset. Specifically, we propose two different compression schemes, one based on powerful binary error-correcting codes employed as source codes, and one based on simpler multilevel coset codes. The performance of both schemes is evaluated on a few AVIRIS scenes, and is compared with other state-of-the-art 2D and 3D coders. Both schemes turn out to achieve competitive compression performance, and one of them also has reduced complexity. Based on these results, we highlight the main issues that are still to be solved to further improve the performance of DSC-based remote sensing systems.

  6. Visual computation of egomotion using an image interpolation technique.

    Science.gov (United States)

    Chahl, J S; Srinivasan, M V

    1996-05-01

    A novel technique is presented for the computation of the parameters of egomotion of a mobile device, such as a robot or a mechanical arm, equipped with two visual sensors. Each sensor captures a panoramic view of the environment. We show the parameters of ego-motion can be computed by interpolating the position of the image captured by one of the sensors at the robot's present location, with respect to the images captured by the two sensors at the robot's previous location. The algorithm delivers the distance travelled and angle rotated, without the explicit measurement or integration of velocity fields. The result is obtained in a single step, without any iteration or successive approximation. Tests of the algorithm on real and synthetic images reveal an accuracy to within 5% of the actual motion. Implementation of the algorithm on a mobile robot reveals that stepwise rotation and translation can be measured to within 10% accuracy in a three-dimensional world of unknown structure. The position and orientation of the robot at the end of a 30-step trajectory can be estimated with accuracies of 5% and 5 degrees, respectively.

  7. A high temperature seeding technique for particle image velocimetry

    Science.gov (United States)

    Wernet, Mark P.; Hadley, Judith A.

    2016-12-01

    Non-intrusive measurements of gas velocities via particle image velocimetry (PIV) or laser Doppler velocimetry (LDV) requires entraining particles into the flow field. There are many techniques and materials available for seeding gas phase flows. However, when the flow temperatures exceed 200 °C, the available options for seed materials becomes limited. In high temperature applications refractory seed materials are required. The established technique for seeding flows with metal oxide powders is via fluidized beds by themselves or in combination with cyclone separators. These systems are fraught with problems which limit their ability to provide consistent, uniform flow seeding. In this work, we describe a technique for reliably introducing metal oxide particles into high temperature flows. The employment of pH stabilization techniques typically used to obtain stable dispersions in ceramic processing can provide a source of seed material for high temperature air flows. By pH stabilizing submicron alumina particles in ethanol, a stable dispersion is obtained which when atomized, produces a high quality aerosol. Commercial grade alumina is used with a moderate size distribution. The technique is not limited to alumina/ethanol and is also demonstrated with an alumina/H2O system. Other ceramic powders in other polar solvents can also be used once their point of zero charge (pHpzc) of the powder in the solvent has been determined. We present an example of the pH stabilized dispersions applied to a very challenging high temperature supersonic flow and a particle dynamics analysis across a shock.

  8. Real-time windowing in imaging radar using FPGA technique

    Science.gov (United States)

    Ponomaryov, Volodymyr I.; Escamilla-Hernandez, Enrique

    2005-02-01

    The imaging radar uses the high frequency electromagnetic waves reflected from different objects for estimating of its parameters. Pulse compression is a standard signal processing technique used to minimize the peak transmission power and to maximize SNR, and to get a better resolution. Usually the pulse compression can be achieved using a matched filter. The level of the side-lobes in the imaging radar can be reduced using the special weighting function processing. There are very known different weighting functions: Hamming, Hanning, Blackman, Chebyshev, Blackman-Harris, Kaiser-Bessel, etc., widely used in the signal processing applications. Field Programmable Gate Arrays (FPGAs) offers great benefits like instantaneous implementation, dynamic reconfiguration, design, and field programmability. This reconfiguration makes FPGAs a better solution over custom-made integrated circuits. This work aims at demonstrating a reasonably flexible implementation of FM-linear signal and pulse compression using Matlab, Simulink, and System Generator. Employing FPGA and mentioned software we have proposed the pulse compression design on FPGA using classical and novel windows technique to reduce the side-lobes level. This permits increasing the detection ability of the small or nearly placed targets in imaging radar. The advantage of FPGA that can do parallelism in real time processing permits to realize the proposed algorithms. The paper also presents the experimental results of proposed windowing procedure in the marine radar with such the parameters: signal is linear FM (Chirp); frequency deviation DF is 9.375MHz; the pulse width T is 3.2μs taps number in the matched filter is 800 taps; sampling frequency 253.125*106 MHz. It has been realized the reducing of side-lobes levels in real time permitting better resolution of the small targets.

  9. High Resolution Ultrasonographic Evaluation of the Gallbladder: Value of Advanced Imaging Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Young; Choi, Byung Ihn; Han, Joon Koo; Lee, Jeong Min; Kim, Se Hyung; Choi, Jin Young; Kim, Su Jin [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2005-12-15

    A prospective study to determine the role of compound imaging, speckle reduction imaging and tissue harmonic imaging techniques in high-resolution gallbladder ultrasound examination. Gallbladders in 39 patients were examined with conventional imaging, compound imaging, compound imaging combined with speckle reduction imaging, and compound imaging combined with harmonic imaging techniques, using 7- to 10-MHz linear array transducer. The overall image qualities, sharpness of the anterior wall, depiction of the wall layers, and degree of internal artifact were evaluated. In cases of a gallbladder lesion, its conspicuity, margin sharpness, and intensity of posterior shadowing were evaluated. Two radiologists independently evaluated each image and graded each finding with a four-part scale. The Wilcoxon signs rank test was used. Compound imaging technique provided better results than conventional imaging technique in all categories except the intensity of posterior shadowing of gallstone (p < 0.01). Compound imaging technique well depicted the gallbladder wall layers in 34 of 39 cases and depicted them better than conventional ultrasonography in 31 of 39 cases. Compound imaging also improved conspicuity and margin sharpness of the lesions. Combined use of compound imaging and speckle reduction imaging technique did not provide better results than compound imaging. Combined use of compound imaging and harmonic imaging provided better overall image quality and fewer internal artifacts than compound imaging (p < 0.05). Compound imaging technique was superior to conventional imaging in evaluating gallbladder and its lesion with high frequency transducer. Combined use of compound imaging and harmonic imaging was helpful to enhance overall image quality and reduce artifacts

  10. Final Project Report: Imaging Fault Zones Using a Novel Elastic Reverse-Time Migration Imaging Technique

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Ting [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tan, Sirui [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lin, Youzuo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gao, Kai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-10

    Imaging fault zones and fractures is crucial for geothermal operators, providing important information for reservoir evaluation and management strategies. However, there are no existing techniques available for directly and clearly imaging fault zones, particularly for steeply dipping faults and fracture zones. In this project, we developed novel acoustic- and elastic-waveform inversion methods for high-resolution velocity model building. In addition, we developed acoustic and elastic reverse-time migration methods for high-resolution subsurface imaging of complex subsurface structures and steeply-dipping fault/fracture zones. We first evaluated and verified the improved capabilities of our newly developed seismic inversion and migration imaging methods using synthetic seismic data. Our numerical tests verified that our new methods directly image subsurface fracture/fault zones using surface seismic reflection data. We then applied our novel seismic inversion and migration imaging methods to a field 3D surface seismic dataset acquired at the Soda Lake geothermal field using Vibroseis sources. Our migration images of the Soda Lake geothermal field obtained using our seismic inversion and migration imaging algorithms revealed several possible fault/fracture zones. AltaRock Energy, Inc. is working with Cyrq Energy, Inc. to refine the geologic interpretation at the Soda Lake geothermal field. Trenton Cladouhos, Senior Vice President R&D of AltaRock, was very interested in our imaging results of 3D surface seismic data from the Soda Lake geothermal field. He planed to perform detailed interpretation of our images in collaboration with James Faulds and Holly McLachlan of University of Nevada at Reno. Using our high-resolution seismic inversion and migration imaging results can help determine the optimal locations to drill wells for geothermal energy production and reduce the risk of geothermal exploration.

  11. Technical study of Germolles’ wall paintings: the inputof imaging technique

    Directory of Open Access Journals (Sweden)

    Christian Degrigny

    2016-11-01

    Full Text Available The Château de Germolles is one of the rare palace in France dating from the 14th century. The noble floor is decorated with wall paintings that are a unique example of courtly love spirit that infused the princely courts of the time. After being concealed sometime in the 19th century, the paintings were rediscovered and uncovered in the middle of the 20th century and partly restored at the end of the 1990s. No scientific documentation accompanied these interventions and important questions, such as the level of authenticity of the mural decorations and the original painting technique(s used in the medieval times remained unanswered. The combined scientific and financial supports of COSCH Cost Action and DRAC-Burgundy enabled to study Germolles’ wall paintings using some of the most innovative imaging and analytical techniques and to address some of the questions raised. The study provided significant information on the material used in the medieval times and on the conservation condition of the paintings. The data collected is vast and varied and exposed the owners of the property to the challenges of data management.

  12. Imaging techniques in the management of anorexia and bulimia nervosa.

    Science.gov (United States)

    Mazzetti di Pietralata, G

    2002-06-01

    This paper discusses the contribution offered by radiological techniques to the diagnosis of the medical and surgical complications of anorexia nervosa (AN) and bulimia (BN) with the aim of providing general indications as to their use and suggesting the best-suited techniques. In the broad field of the complications of malnourishment, the use of magnetic resonance (MR) instead of computed tomography (CT) in the assessment of brain atrophy provides much more information at a better cost-benefit ratio. Like brain atrophy, other complications may be chance radiographic findings, such as cathartic colon and colon ptosis. Pulmonary tuberculosis and the presence of bronchopneumonia in conditions of malnutrition demand that conventional X-rays be supplemented by high-resolution CT scans, MR and echotomography. When checking for parotidomegaly and polycystic ovary, the best imaging technique is echotomography. Radiologists are also called upon to express their view in the case of emergencies such as the rupture of the esophagus and osteoporosis-induced fractures.

  13. Recent developments at JPL in the application of digital image processing techniques to astronomical images

    Science.gov (United States)

    Lorre, J. J.; Lynn, D. J.; Benton, W. D.

    1976-01-01

    Several techniques of a digital image-processing nature are illustrated which have proved useful in visual analysis of astronomical pictorial data. Processed digital scans of photographic plates of Stephans Quintet and NGC 4151 are used as examples to show how faint nebulosity is enhanced by high-pass filtering, how foreground stars are suppressed by linear interpolation, and how relative color differences between two images recorded on plates with different spectral sensitivities can be revealed by generating ratio images. Analyses are outlined which are intended to compensate partially for the blurring effects of the atmosphere on images of Stephans Quintet and to obtain more detailed information about Saturn's ring structure from low- and high-resolution scans of the planet and its ring system. The employment of a correlation picture to determine the tilt angle of an average spectral line in a low-quality spectrum is demonstrated for a section of the spectrum of Uranus.

  14. Multiparametric magnetic resonance imaging of the prostate: current concepts.

    NARCIS (Netherlands)

    Bittencourt, L.K.; Hausmann, D.; Sabaneeff, N.; Gasparetto, E.L.; Barentsz, J.O.

    2014-01-01

    Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI).

  15. Multiparametric magnetic resonance imaging of the prostate: current concepts.

    NARCIS (Netherlands)

    Bittencourt, L.K.; Hausmann, D.; Sabaneeff, N.; Gasparetto, E.L.; Barentsz, J.O.

    2014-01-01

    Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI).

  16. Systematic infrared image quality improvement using deep learning based techniques

    Science.gov (United States)

    Zhang, Huaizhong; Casaseca-de-la-Higuera, Pablo; Luo, Chunbo; Wang, Qi; Kitchin, Matthew; Parmley, Andrew; Monge-Alvarez, Jesus

    2016-10-01

    Infrared thermography (IRT, or thermal video) uses thermographic cameras to detect and record radiation in the longwavelength infrared range of the electromagnetic spectrum. It allows sensing environments beyond the visual perception limitations, and thus has been widely used in many civilian and military applications. Even though current thermal cameras are able to provide high resolution and bit-depth images, there are significant challenges to be addressed in specific applications such as poor contrast, low target signature resolution, etc. This paper addresses quality improvement in IRT images for object recognition. A systematic approach based on image bias correction and deep learning is proposed to increase target signature resolution and optimise the baseline quality of inputs for object recognition. Our main objective is to maximise the useful information on the object to be detected even when the number of pixels on target is adversely small. The experimental results show that our approach can significantly improve target resolution and thus helps making object recognition more efficient in automatic target detection/recognition systems (ATD/R).

  17. Adequate image quality with reduced radiation dose in prospectively triggered coronary CTA compared with retrospective techniques

    Energy Technology Data Exchange (ETDEWEB)

    Arnoldi, Elisabeth; Johnson, Thorsten R.; Rist, Carsten; Wintersperger, Bernd J.; Sommer, Wieland H.; Becker, Christoph R.; Reiser, Maximilian F.; Nikolaou, Konstantin [Ludwig-Maximilians University, Department of Clinical Radiology, University Hospitals Munich - Grosshadern Campus, Munich (Germany); Becker, Alexander [Ludwig-Maximilians University, Department of Medicine I, University Hospitals Munich - Grosshadern Campus, Munich (Germany)

    2009-09-15

    The goal of our study was to compare a prospective triggering (PT) CT technique with retrospectively gated (RG) CT techniques in coronary computed tomographic angiograms (CCTA) with respect to image quality and radiation dose. Sixty consecutive patients were enrolled. CCTAs using the RG technique were obtained with a dual-source 64-slice CT system in 40 patients, using ECG-triggered tube current modulation, with either a broad pulsing window at 30-80% of the RR interval (group RGb, 20 patients, heart rate > 70 bpm) or a small pulsing window at 70% (group RGs, 20 patients, heart rate < 70 bpm). The other 20 patients underwent CCTA using the PT technique on a 128-slice CT system (group PT, heart rate < 70 bpm). All images were evaluated by two observers for quality on a three-point scale, with 1 being excellent and 3 being insufficient. The effective radiation dose was calculated for each patient. The average image quality score was 1.5 {+-} 0.6 for PT, 1.35 {+-} 0.5 for RGs and 1.65 {+-} 0.5 for RGb. The mean effective dose for RGb was 9 {+-} 4 mSv, for RGs 7 {+-} 3 mSv and for PT 3 {+-} 1 mSv. This represents a 57% dose reduction for PT compared with RGs and a 67% dose reduction for PT compared with RGb. In conclusion, in selected patients CCTA with the PT technique offers adequate image quality with a significantly lower radiation dose compared with CCTA using RG techniques. (orig.)

  18. 3D-TV System with Depth-Image-Based Rendering Architectures, Techniques and Challenges

    CERN Document Server

    Zhao, Yin; Yu, Lu; Tanimoto, Masayuki

    2013-01-01

    Riding on the success of 3D cinema blockbusters and advances in stereoscopic display technology, 3D video applications have gathered momentum in recent years. 3D-TV System with Depth-Image-Based Rendering: Architectures, Techniques and Challenges surveys depth-image-based 3D-TV systems, which are expected to be put into applications in the near future. Depth-image-based rendering (DIBR) significantly enhances the 3D visual experience compared to stereoscopic systems currently in use. DIBR techniques make it possible to generate additional viewpoints using 3D warping techniques to adjust the perceived depth of stereoscopic videos and provide for auto-stereoscopic displays that do not require glasses for viewing the 3D image.   The material includes a technical review and literature survey of components and complete systems, solutions for technical issues, and implementation of prototypes. The book is organized into four sections: System Overview, Content Generation, Data Compression and Transmission, and 3D V...

  19. In Vivo Imaging of Nitric Oxide by Magnetic Resonance Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Rakesh Sharma

    2014-01-01

    Full Text Available Nitric oxide (NO biosensors are novel tools for real-time bioimaging of tissue oxygen changes and physiological monitoring of tissue vasculature. Nitric oxide behavior further enhances its role in mapping signal transduction at the molecular level. Spectrometric electron paramagnetic resonance (EPR and fluorometric imaging are well known techniques with the potential for in vivo bioimaging of NO. In tissues, NO is a specific target of nitrosyl compounds for chemical reaction, which provides a unique opportunity for application of newly identified NO biosensors. However, the accuracy and sensitivity of NO biosensors still need to be improved. Another potential magnetic resonance technique based on short term NO effects on proton relaxation enhancement is magnetic resonance imaging (MRI, and some NO biosensors may be used as potent imaging contrast agents for measurement of tumor size by MRI combined with fluorescent imaging. The present review provides supporting information regarding the possible use of nitrosyl compounds as NO biosensors in MRI and fluorescent bioimaging showing their measurement limitations and quantitative accuracy. These new approaches open a perspective regarding bioimaging of NO and the in vivo elucidation of NO effects by magnetic resonance techniques.

  20. Colour image segmentation using unsupervised clustering technique for acute leukemia images

    Science.gov (United States)

    Halim, N. H. Abd; Mashor, M. Y.; Nasir, A. S. Abdul; Mustafa, N.; Hassan, R.

    2015-05-01

    Colour image segmentation has becoming more popular for computer vision due to its important process in most medical analysis tasks. This paper proposes comparison between different colour components of RGB(red, green, blue) and HSI (hue, saturation, intensity) colour models that will be used in order to segment the acute leukemia images. First, partial contrast stretching is applied on leukemia images to increase the visual aspect of the blast cells. Then, an unsupervised moving k-means clustering algorithm is applied on the various colour components of RGB and HSI colour models for the purpose of segmentation of blast cells from the red blood cells and background regions in leukemia image. Different colour components of RGB and HSI colour models have been analyzed in order to identify the colour component that can give the good segmentation performance. The segmented images are then processed using median filter and region growing technique to reduce noise and smooth the images. The results show that segmentation using saturation component of HSI colour model has proven to be the best in segmenting nucleus of the blast cells in acute leukemia image as compared to the other colour components of RGB and HSI colour models.

  1. Technique for gray-scale visual light and infrared image fusion based on non-subsampled shearlet transform

    Science.gov (United States)

    Kong, Weiwei

    2014-03-01

    A novel image fusion technique based on NSST (non-subsampled shearlet transform) is presented, aiming at resolving the fusion problem of spatially gray-scale visual light and infrared images. NSST, as a new member of MGA (multi-scale geometric analysis) tools, possesses not only flexible direction features and optimal shift-invariance, but much better fusion performance and lower computational costs compared with several current popular MGA tools such as NSCT (non-subsampled contourlet transform). We specifically propose new rules for the fusion of low and high frequency sub-band coefficients of source images in the second step of the NSST-based image fusion algorithm. First, the source images are decomposed into different scales and directions using NSST. Then, the model of region average energy (RAE) is proposed and adopted to fuse the low frequency sub-band coefficients of the gray-scale visual light and infrared images. Third, the model of local directional contrast (LDC) is given and utilized to fuse the corresponding high frequency sub-band coefficients. Finally, the final fused image is obtained by using inverse NSST to all fused sub-images. In order to verify the effectiveness of the proposed technique, several current popular ones are compared over three different publicly available image sets using four evaluation metrics, and the experimental results demonstrate that the proposed technique performs better in both subjective and objective qualities.

  2. Sparse Reconstruction Techniques in Magnetic Resonance Imaging: Methods, Applications, and Challenges to Clinical Adoption.

    Science.gov (United States)

    Yang, Alice C; Kretzler, Madison; Sudarski, Sonja; Gulani, Vikas; Seiberlich, Nicole

    2016-06-01

    The family of sparse reconstruction techniques, including the recently introduced compressed sensing framework, has been extensively explored to reduce scan times in magnetic resonance imaging (MRI). While there are many different methods that fall under the general umbrella of sparse reconstructions, they all rely on the idea that a priori information about the sparsity of MR images can be used to reconstruct full images from undersampled data. This review describes the basic ideas behind sparse reconstruction techniques, how they could be applied to improve MRI, and the open challenges to their general adoption in a clinical setting. The fundamental principles underlying different classes of sparse reconstructions techniques are examined, and the requirements that each make on the undersampled data outlined. Applications that could potentially benefit from the accelerations that sparse reconstructions could provide are described, and clinical studies using sparse reconstructions reviewed. Lastly, technical and clinical challenges to widespread implementation of sparse reconstruction techniques, including optimization, reconstruction times, artifact appearance, and comparison with current gold standards, are discussed.

  3. Updates in advanced diffusion-weighted magnetic resonance imaging techniques in the evaluation of prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Hebert; Alberto; Vargas; Edward; Malnor; Lawrence; Yousef; Mazaheri; Evis; Sala

    2015-01-01

    Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DWMRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the nonmono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging(DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer.

  4. Image-Guided Hydrodynamic Gene Delivery: Current Status and Future Directions

    Directory of Open Access Journals (Sweden)

    Kenya Kamimura

    2015-08-01

    Full Text Available Hydrodynamics-based delivery has been used as an experimental tool to express transgene in small animals. This in vivo gene transfer method is useful for functional analysis of genetic elements, therapeutic effect of oligonucleotides, and cancer cells to establish the metastatic cancer animal model for experimental research. Recent progress in the development of image-guided procedure for hydrodynamics-based gene delivery in large animals directly supports the clinical applicability of this technique. This review summarizes the current status and recent progress in the development of hydrodynamics-based gene delivery and discusses the future directions for its clinical application.

  5. A methodology for automated CPA extraction using liver biopsy image analysis and machine learning techniques.

    Science.gov (United States)

    Tsipouras, Markos G; Giannakeas, Nikolaos; Tzallas, Alexandros T; Tsianou, Zoe E; Manousou, Pinelopi; Hall, Andrew; Tsoulos, Ioannis; Tsianos, Epameinondas

    2017-03-01

    Collagen proportional area (CPA) extraction in liver biopsy images provides the degree of fibrosis expansion in liver tissue, which is the most characteristic histological alteration in hepatitis C virus (HCV). Assessment of the fibrotic tissue is currently based on semiquantitative staging scores such as Ishak and Metavir. Since its introduction as a fibrotic tissue assessment technique, CPA calculation based on image analysis techniques has proven to be more accurate than semiquantitative scores. However, CPA has yet to reach everyday clinical practice, since the lack of standardized and robust methods for computerized image analysis for CPA assessment have proven to be a major limitation. The current work introduces a three-stage fully automated methodology for CPA extraction based on machine learning techniques. Specifically, clustering algorithms have been employed for background-tissue separation, as well as for fibrosis detection in liver tissue regions, in the first and the third stage of the methodology, respectively. Due to the existence of several types of tissue regions in the image (such as blood clots, muscle tissue, structural collagen, etc.), classification algorithms have been employed to identify liver tissue regions and exclude all other non-liver tissue regions from CPA computation. For the evaluation of the methodology, 79 liver biopsy images have been employed, obtaining 1.31% mean absolute CPA error, with 0.923 concordance correlation coefficient. The proposed methodology is designed to (i) avoid manual threshold-based and region selection processes, widely used in similar approaches presented in the literature, and (ii) minimize CPA calculation time. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Extending Driving Vision Based on Image Mosaic Technique

    Directory of Open Access Journals (Sweden)

    Chen Deng

    2017-01-01

    Full Text Available Car cameras have been used extensively to assist driving by make driving visible. However, due to the limitation of the Angle of View (AoV, the dead zone still exists, which is a primary origin of car accidents. In this paper, we introduce a system to extend the vision of drivers to 360 degrees. Our system consists of four wide-angle cameras, which are mounted at different sides of a car. Although the AoV of each camera is within 180 degrees, relying on the image mosaic technique, our system can seamlessly integrate 4-channel videos into a panorama video. The panorama video enable drivers to observe everywhere around a car as far as three meters from a top view. We performed experiments in a laboratory environment. Preliminary results show that our system can eliminate vision dead zone completely. Additionally, the real-time performance of our system can satisfy requirements for practical use.

  7. Stalked protozoa identification by image analysis and multivariable statistical techniques.

    Science.gov (United States)

    Amaral, A L; Ginoris, Y P; Nicolau, A; Coelho, M A Z; Ferreira, E C

    2008-06-01

    Protozoa are considered good indicators of the treatment quality in activated sludge systems as they are sensitive to physical, chemical and operational processes. Therefore, it is possible to correlate the predominance of certain species or groups and several operational parameters of the plant. This work presents a semiautomatic image analysis procedure for the recognition of the stalked protozoa species most frequently found in wastewater treatment plants by determining the geometrical, morphological and signature data and subsequent processing by discriminant analysis and neural network techniques. Geometrical descriptors were found to be responsible for the best identification ability and the identification of the crucial Opercularia and Vorticella microstoma microorganisms provided some degree of confidence to establish their presence in wastewater treatment plants.

  8. BATMAN: Bayesian Technique for Multi-image Analysis

    Science.gov (United States)

    Casado, J.; Ascasibar, Y.; García-Benito, R.; Guidi, G.; Choudhury, O. S.; Bellocchi, E.; Sánchez, S. F.; Díaz, A. I.

    2016-12-01

    This paper describes the Bayesian Technique for Multi-image Analysis (BATMAN), a novel image-segmentation technique based on Bayesian statistics that characterizes any astronomical dataset containing spatial information and performs a tessellation based on the measurements and errors provided as input. The algorithm iteratively merges spatial elements as long as they are statistically consistent with carrying the same information (i.e. identical signal within the errors). We illustrate its operation and performance with a set of test cases including both synthetic and real Integral-Field Spectroscopic data. The output segmentations adapt to the underlying spatial structure, regardless of its morphology and/or the statistical properties of the noise. The quality of the recovered signal represents an improvement with respect to the input, especially in regions with low signal-to-noise ratio. However, the algorithm may be sensitive to small-scale random fluctuations, and its performance in presence of spatial gradients is limited. Due to these effects, errors may be underestimated by as much as a factor of two. Our analysis reveals that the algorithm prioritizes conservation of all the statistically-significant information over noise reduction, and that the precise choice of the input data has a crucial impact on the results. Hence, the philosophy of BATMAN is not to be used as a `black box' to improve the signal-to-noise ratio, but as a new approach to characterize spatially-resolved data prior to its analysis. The source code is publicly available at http://astro.ft.uam.es/SELGIFS/BaTMAn.

  9. Determination of confinement efficiency in tokamaks based on current independent flux loops technique

    Science.gov (United States)

    Salar Elahi, A.; Ghoranneviss, M.

    In this contribution we presented a current independent approximation of the combination of poloidal beta and internal inductance (confinement efficiency) only based on poloidal flux loops measurement in IR-T1 tokamak. The main advantage of this technique is that it based only on the one diagnostic (only flux loops and not need to plasma current measurement). Based on this method, two flux loops were designed, constructed, and installed on outer surface of the IR-T1 tokamak chamber and then the Shafranov parameter was measured from them. Also the result of this technique was compared with conventional magnetic probes technique and found in good agreement with each other.

  10. New endoscopic imaging techniques in surveillance ofinflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Tommaso Gabbani; Natalia Manetti; Andrea Giovanni Bonanomi; Antonio Luca Annese; Vito Annese

    2015-01-01

    Endoscopy plays a crucial role in the managementof inflammatory bowel disease (IBD). Advancesimaging techniques allow visualization of mucosaldetails, tissue characteristics and cellular alteration. Inparticular chromoendoscopy, magnification endoscopy,confocal laser endomicroscopy and endocytoscopyseem to have the possibility to radically modify theapproach to surveillance and decision making. Dyebasedchromoendoscopy (DBC) and magnificationchromoendoscopy improve detection of dysplasia,and evaluation of inflammatory activity and extensionof ulcerative colitis and are thus considered thestandard of care. Dye-less chromoendoscopy couldprobably replace conventional DBC for surveillance.Narrow band imaging and i-scan have shown toimprove activity and extent assessment in comparisonto white-light endoscopy. Confocal laser endomicroscopy(CLE) can detect more dysplastic lesions insurveillance colonoscopy and predict neoplastic andinflammatory changes with high accuracy comparedto histology. This technology is best used in conjunctionwith chromoendoscopy, narrow-band imaging, orautofluorescence because of its minute scanning area.This combination is useful for appropriate tissueclassification of mucosal lesions already detectedby standard or optically enhanced endoscopy. Thebest combination for IBD surveillance appear tobe chromoendoscopy for identification of areas ofsuspicion, with further examination with CLE to detectintraepithelial neoplasia. However cost, availability, andexperience are still an issue.

  11. Content Based Image Retrieval using Hierarchical and K-Means Clustering Techniques

    Directory of Open Access Journals (Sweden)

    V.S.V.S. Murthy

    2010-03-01

    Full Text Available In this paper we present an image retrieval system that takes an image as the input query and retrieves images based on image content. Content Based Image Retrieval is an approach for retrieving semantically-relevant images from an image database based on automatically-derived image features. The unique aspect of the system is the utilization of hierarchical and k-means clustering techniques. The proposed procedure consists of two stages. First, here we are going to filter most of the images in the hierarchical clustering and then apply the clustered images to KMeans, so that we can get better favored image results.

  12. Current Status of Imaging Physics and Instrumentation In Nuclear Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee Joung [Institute of Health Science, Yonsei University, Seoul (Korea, Republic of)

    2008-04-15

    Diagnostic and functional imaging device have been developed independently. The recognition that combining of these two devices can provide better diagnostic outcomes by fusing anatomical and functional images. The representative examples of combining devices would be PET/CT and SPECT/CT. Development and their applications of animal imaging and instrumentation have been very active, as new drug development with advanced imaging device has been increased. The development of advanced imaging device resulted in researching and developing for detector technology and imaging systems. It also contributed to develop a new software, reconstruction algorithm, correction methods for physical factors, image quantitation, computer simulation, kinetic modeling, dosimetry, and correction for motion artifacts. Recently, development of MRI and PET by combining them together was reported. True integration of MRI and PET has been making the progress and their results were reported. The recent status of imaging and instrumentation in nuclear medicine is reported in this paper.

  13. The current progress of the ALICE Ring Imaging Cherenkov Detector

    CERN Document Server

    Braem, André; Davenport, M; Mauro, A D; Franco, A; Gallas, A; Hoedlmoser, H; Martinengo, P; Nappi, E; Paic, G; Piuz, François; Peskov, Vladimir

    2007-01-01

    Recently, the last two modules (out of seven) of the ALICE High Momentum Particle Identification detector (HMPID) were assembled and tested. The full detector, after a pre-commissioning phase, has been installed in the experimental area, inside the ALICE solenoid, at the end of September 2006. In this paper we review the status of the ALICE/HMPID project and we present a summary of the series production of the CsI photo-cathodes. We describe the key features of the production procedure which ensures high quality photo-cathodes as well as the results of the quality assessment performed by means of a specially developed 2D scanner system able to produce a detailed map of the CsI photo-current over the entire photo-cathode surface. Finally we present our recent R&D efforts toward the development of a novel generation of imaging Cherenkov detectors with the aim to identify, in heavy ions collisions, hadrons up to 30 GeV/c.

  14. Burnout prediction using advance image analysis coal characterization techniques

    Energy Technology Data Exchange (ETDEWEB)

    Edward Lester; Dave Watts; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical Environmental and Mining Engineering

    2003-07-01

    The link between petrographic composition and burnout has been investigated previously by the authors. However, these predictions were based on 'bulk' properties of the coal, including the proportion of each maceral or the reflectance of the macerals in the whole sample. Combustion studies relating burnout with microlithotype analysis, or similar, remain less common partly because the technique is more complex than maceral analysis. Despite this, it is likely that any burnout prediction based on petrographic characteristics will become more accurate if it includes information about the maceral associations and the size of each particle. Chars from 13 coals, 106-125 micron size fractions, were prepared using a Drop Tube Furnace (DTF) at 1300{degree}C and 200 millisecond and 1% Oxygen. These chars were then refired in the DTF at 1300{degree}C 5% oxygen and residence times of 200, 400 and 600 milliseconds. The progressive burnout of each char was compared with the characteristics of the initial coals. This paper presents an extension of previous studies in that it relates combustion behaviour to coals that have been characterized on a particle by particle basis using advanced image analysis techniques. 13 refs., 7 figs.

  15. Digital Image Processing Technique for Breast Cancer Detection

    Science.gov (United States)

    Guzmán-Cabrera, R.; Guzmán-Sepúlveda, J. R.; Torres-Cisneros, M.; May-Arrioja, D. A.; Ruiz-Pinales, J.; Ibarra-Manzano, O. G.; Aviña-Cervantes, G.; Parada, A. González

    2013-09-01

    Breast cancer is the most common cause of death in women and the second leading cause of cancer deaths worldwide. Primary prevention in the early stages of the disease becomes complex as the causes remain almost unknown. However, some typical signatures of this disease, such as masses and microcalcifications appearing on mammograms, can be used to improve early diagnostic techniques, which is critical for women’s quality of life. X-ray mammography is the main test used for screening and early diagnosis, and its analysis and processing are the keys to improving breast cancer prognosis. As masses and benign glandular tissue typically appear with low contrast and often very blurred, several computer-aided diagnosis schemes have been developed to support radiologists and internists in their diagnosis. In this article, an approach is proposed to effectively analyze digital mammograms based on texture segmentation for the detection of early stage tumors. The proposed algorithm was tested over several images taken from the digital database for screening mammography for cancer research and diagnosis, and it was found to be absolutely suitable to distinguish masses and microcalcifications from the background tissue using morphological operators and then extract them through machine learning techniques and a clustering algorithm for intensity-based segmentation.

  16. Technique Based on Image Pyramid and Bayes Rule for Noise Reduction in Unsupervised Change Detection

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-qiang; HUO hong; FANG Tao; ZHU Ju-lian; GE Wei-li

    2009-01-01

    In this paper, a technique based on image pyramid and Bayes rule for reducing noise effects in unsupervised change detection is proposed. By using Gaussian pyramid to process two multitemporal images respectively, two image pyramids are constructed. The difference pyramid images are obtained by point-by-point subtraction between the same level images of the two image pyramids. By resizing all difference pyramid images to the size of the original multitemporal image and then making product operator among them, a map being similar to the difference image is obtained. The difference image is generated by point-by-point subtraction between the two multitemporal images directly. At last, the Bayes rule is used to distinguish the changed pixels. Both synthetic and real data sets are used to evaluate the performance of the proposed technique. Experimental results show that the map from the proposed technique is more robust to noise than the difference image.

  17. Current and future imaging modalities for multiple myeloma and its precursor states

    Science.gov (United States)

    TAN, ESTHER; WEISS, BRENDAN M.; MENA, ESTHER; KORDE, NEHA; CHOYKE, PETER L.; LANDGREN, OLA

    2012-01-01

    Traditionally, the skeletal survey has been the standard modality for the detection of osteolytic bone disease in multiple myeloma. In addition to its poor sensitivity for the detection of osteolytic lesions, this modality is not able to identify extramedullary lesions and focal bone marrow involvement, nor measure response to therapy. The application of novel imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and molecular imaging such as fluorine-18 fluorodeoxyglucose positron emission tomography CT (18F-FDG PET/CT) and fluorine-18 sodium fluoride positron emission tomography CT (18F-NaF PET/CT) has the potential to overcome these limitations as well as provide prognostic information in precursor states and multiple myeloma. Also promising is the use of dynamic contrast enhanced magnetic resonance imaging (DCE MRI) to measure vascular permeability, an important feature of myelomagenesis. This review summarizes the current status and possible future role of novel imaging modalities in multiple myeloma and its precursor states. PMID:21649546

  18. Hysteresis Current Control technique based on Space Vector Modulation for Active Power Filter

    Directory of Open Access Journals (Sweden)

    Wang Yun-liang

    2011-09-01

    Full Text Available In this paper, the hysteresis current control (HCC technique based on space vector modulation (SVM for shunt active power filter (APF is proposed. The switching control algorithms of the HCC based SVM manage to generate compensated current according to the reference current. Harmonics extraction is based on the instantaneous active and reactive power theorem in time domain by calculating the power compensation. A closed loop control system is carried out and the error current is the difference between the reference current which is obtained from the power compensation and the actual current needs to be injected back into the power grid. By implementing this control strategy, the APF manages to generate better compensated harmonics currents to the power grid. Keywords: active power filter, hysteresis current control, space vector modulation ,matlab/simulink

  19. Current challenges and future directions in cardiac imaging.

    Science.gov (United States)

    Wann, Samuel; Tunio, Javed

    2010-07-01

    Imaging is one of the most important accomplishments of medicine during the last 1000 years. The contribution of modern imaging to progress in the delivery of health care is unquestioned. However, we need to refine our use of imaging, limiting its use to those occasions when it can contribute directly or indirectly to improving and lengthening the lives of patients. Technology prowess in imaging alone is not sufficient to deliver value to individuals or to society. Continued investment in imaging technology requires critical appraisal of its use in clinical decision making and patient outcomes.

  20. Study of optical techniques for the Ames unitary wind tunnel: Digital image processing, part 6

    Science.gov (United States)

    Lee, George

    1993-01-01

    A survey of digital image processing techniques and processing systems for aerodynamic images has been conducted. These images covered many types of flows and were generated by many types of flow diagnostics. These include laser vapor screens, infrared cameras, laser holographic interferometry, Schlieren, and luminescent paints. Some general digital image processing systems, imaging networks, optical sensors, and image computing chips were briefly reviewed. Possible digital imaging network systems for the Ames Unitary Wind Tunnel were explored.