Download or read book Quantitative Analysis and Improvement of Retinal Image Quality written by Yirong Yang and published by . This book was released on 2008-07-01 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Retinal image formation through the optics of the human eye is the first step in the complex process of vision. Imperfections in the optics of the human eye, including aberrations and scatter, degrade retinal image quality. Determination of the contribution of ocular aberrations and light scatter to decreased retinal image quality, particularly in aging and diseased eyes, is essential to evaluate optical quality of the eye. Correction of ocular aberrations can enable acquiring retinal images with high spatial resolution. An optical imaging system has been established that provides for combined measurements of ocular aberrations and light scatter. Wavefront sensing was performed with a Shack-Hartmann aberrometer to determine the wavefront aberration function and calculate the point spread function, giving information on ocular aberrations. A line spread function was derived from the laser slit, giving information on combined ocular aberrations and light scatter. A relative index for ocular light scatter was derived. A hybrid deconvolution method for improving retinal image quality was developed.
Download or read book Computational Retinal Image Analysis written by Emanuele Trucco and published by Academic Press. This book was released on 2019-12-04 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Retinal Image Analysis: Tools, Applications and Perspectives gives an overview of contemporary retinal image analysis (RIA) in the context of healthcare informatics and artificial intelligence. Specifically, it provides a history of the field, the clinical motivation for RIA, technical foundations (image acquisition modalities, instruments), computational techniques for essential operations, lesion detection (e.g. optic disc in glaucoma, microaneurysms in diabetes) and validation, as well as insights into current investigations drawing from artificial intelligence and big data. This comprehensive reference is ideal for researchers and graduate students in retinal image analysis, computational ophthalmology, artificial intelligence, biomedical engineering, health informatics, and more. Provides a unique, well-structured and integrated overview of retinal image analysis Gives insights into future areas, such as large-scale screening programs, precision medicine, and computer-assisted eye care Includes plans and aspirations of companies and professional bodies
Download or read book Retinal Optical Coherence Tomography Image Analysis written by Xinjian Chen and published by Springer. This book was released on 2019-07-05 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the latest optical coherence tomography (OCT) imaging and computerized automatic image analysis techniques, and their applications in the diagnosis and treatment of retinal diseases. Discussing the basic principles and the clinical applications of OCT imaging, OCT image preprocessing, as well as the automatic detection and quantitative analysis of retinal anatomy and pathology, it includes a wealth of clinical OCT images, and state-of-the-art research that applies novel image processing, pattern recognition and machine learning methods to real clinical data. It is a valuable resource for researchers in both medical image processing and ophthalmic imaging.
Download or read book Registration and Quantitative Analysis of Retinal Images and Sequences written by Adrià Pérez Rovira and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Analysis and Modeling of Confocal Retinal Images written by Jiyun Byun and published by ProQuest. This book was released on 2007 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: Images have become critical components for a detailed understanding of the structure and function of cells and proteins. For example, confocal microscopy images are used to obtain a better understanding of several critical functions of the central nervous system (CNS), such as mechanisms behind the loss and recovery of vision following retinal detachment. Image processing and information discovery tools increasingly play a significant role in better harvesting these vast amounts of data, most of which is currently analyzed manually and qualitatively.
Download or read book Image Analysis and Recognition written by Fakhri Karray and published by Springer. This book was released on 2017-06-19 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed proceedings of the 14th International Conference on Image Analysis and Recognition, ICIAR 2017, held in Montreal, QC, Canada, in July 2017. The 73 revised full papers presented were carefully reviewed and selected from 133 submissions. The papers are organized in the following topical sections: machine learning in image recognition; machine learning for medical image computing; image enhancement and reconstruction; image segmentation; motion and tracking; 3D computer vision; feature extraction; detection and classification; biomedical image analysis; image analysis in ophthalmology; remote sensing; applications.
Download or read book High Resolution Imaging in Microscopy and Ophthalmology written by Josef F. Bille and published by Springer. This book was released on 2019-08-13 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book provides a comprehensive overview of the application of the newest laser and microscope/ophthalmoscope technology in the field of high resolution imaging in microscopy and ophthalmology. Starting by describing High-Resolution 3D Light Microscopy with STED and RESOLFT, the book goes on to cover retinal and anterior segment imaging and image-guided treatment and also discusses the development of adaptive optics in vision science and ophthalmology. Using an interdisciplinary approach, the reader will learn about the latest developments and most up to date technology in the field and how these translate to a medical setting. High Resolution Imaging in Microscopy and Ophthalmology – New Frontiers in Biomedical Optics has been written by leading experts in the field and offers insights on engineering, biology, and medicine, thus being a valuable addition for scientists, engineers, and clinicians with technical and medical interest who would like to understand the equipment, the applications and the medical/biological background. Lastly, this book is dedicated to the memory of Dr. Gerhard Zinser, co-founder of Heidelberg Engineering GmbH, a scientist, a husband, a brother, a colleague, and a friend.
Download or read book Analytical Tools for High Resolution OCT Imaging of Human Retina written by Hitesh Pratapkumar Tanna and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advent of optical coherence tomography (OCT), remarkably detailed information about retina is now available. However, most of the clinical use of OCT relies on qualitative analysis of the data. While technological advances have provided increased resolution and quicker data acquisition, the clinical utility of OCT has not been fully realized as quantitative methods for image analysis have not kept pace with the technological advances. Hence, there is a pressing need to develop analytical tools that allow OCT to achieve its full potential as an early diagnostic tool of early degenerations. This study examined the practical improvement in image quality afforded by a broadband light source in a clinical setting and defined image quality metrics for future use in evaluating spectral domain optical coherence tomography (SD-OCT) images. Significant improvement in local contrast, resolution and contrast to noise ratio was found using a commercial broad-band light source. Horizontal striations within the IPL were also observed and believed to represent synaptic sub lamination, though further investigation is required. A novel automated segmentation algorithm to extract four retinal boundaries was developed and verified against the current gold standard - manual segmentation. This algorithm provided accurate, reliable and reproducible thickness measurements for linear and volumetric scans. The algorithm was developed for segmenting healthy retinal images, and hence can be used for normative database for thickness profiles of retinal layers.
Download or read book Proceedings of the 12th International Conference on Robotics Vision Signal Processing and Power Applications written by Nur Syazreen Ahmad and published by Springer Nature. This book was released on with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Classification in BioApps written by Nilanjan Dey and published by Springer. This book was released on 2017-11-10 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book on classification in biomedical image applications presents original and valuable research work on advances in this field, which covers the taxonomy of both supervised and unsupervised models, standards, algorithms, applications and challenges. Further, the book highlights recent scientific research on artificial neural networks in biomedical applications, addressing the fundamentals of artificial neural networks, support vector machines and other advanced classifiers, as well as their design and optimization. In addition to exploring recent endeavours in the multidisciplinary domain of sensors, the book introduces readers to basic definitions and features, signal filters and processing, biomedical sensors and automation of biomeasurement systems. The target audience includes researchers and students at engineering and medical schools, researchers and engineers in the biomedical industry, medical doctors and healthcare professionals.
Download or read book A Computer aided System for Interactive Image Analysis of Retinal Pathologies Using Optical Coherence Tomography written by Sudarshan Ranganathan and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this thesis is to design a new stand-alone application software consisting of a Graphical User Interface (GUI) that will integrate a novel automatic segmentation of the retinal images obtained from the StratusOCT(TM) system along with a new developed manual correction tool that will aid in eliminating segmentation errors. Additionally, the GUI will integrate a set of programmed functions to facilitate the pre- and post-processing of the StratusOCT(TM) images. It will also generate a quantitative analysis report that can be exported as a spreadsheet to Microsoft Excel along with a PDF document. As a result, the GUI will facilitate the measurements of thickness and reflectance of the various retinal layers, leading to a potential improvement in the quantitative analysis of StratusOCT(TM) images.
Download or read book Retinal Imaging written by Christopher James Cookson and published by . This book was released on 2013 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this thesis is the improvement of acquisition and processing of Mueller matrix polarimetry using a confocal scanning laser ophthalmoscope (CSLO) and the application of Mueller matrix polarimetry to image the retina. Stepper motors were incorporated into a CSLO to semi-automate Mueller matrix polarimetry and were used in retinal image acquisition. Success rates of Fourier transform based edge detection filters, designed to improve the registration of retinal images, were compared. The acquired polarimetry images were used to reassess 2 image quality enhancement techniques, Mueller matrix reconstruction (MMR) and Stokes vector reconstruction (SVR), focusing on the role of auto-contrasting or normalization within the techniques and the degree to which auto-contrasting or normalization is responsible for image quality improvement of the resulting images. Mueller matrix polarimetry was also applied to find the retardance image of a malaria infected retinal blood vessel imaged in a confocal scanning laser microscope (CSLM) to visualize hemozoin within the vessel. Image quality enhancement techniques were also applied and image quality improvement was quantified for this blood vessel. The semi-automation of Mueller matrix polarimetry yielded a significant reduction in experimental acquisition time (80%) and a non-significant reduction in registration time (44%). A larger sample size would give higher power and this result might become significant. The reduction in registration time was most likely due to less movement of the eye, particularly in terms of decreased rotation seen between registered images. Fourier transform edge detection methods increased the success rate of registration from 73.9% to 92.3%. Assessment of the 2 MMR images (max entropy and max signal-to-noise ratio (SNR)) showed that comparison to the best CSLO images (not auto-contrasted) yielded significant average image quality improvements of 158% and 4% when quantified with entropy and SNR, respectively. When compared to best auto-contrasted CSLO images, significant image quality improvements were 11% and 5% for entropy and SNR, respectively. Images constructed from auto-contrasted input images were of significantly higher quality than images reconstructed from original images. Of the 2 other images assessed (modified degree of polarization (DOPM) and the first element of the Stokes vector (S0)), DOPM and S0 yielded significant average image quality improvements quantified by entropy except for the DOPM image of the RNFL. SNR was not improved significantly when either SVR image was compared to the best CSLO images. Compared to the best auto-contrasted CSLO images, neither DOPM nor S0 improved average image quality significantly. This result might change with a larger number of participants. When MMR were applied to images of malaria infected retinal slides, image quality was improved by 19.7% and 15.3% in terms of entropy and SNR, respectively, when compared to the best CSLO image. The DOPM image yielded image quality improvements of 8.6% and -24.3% and the S0 image gave improvements of 9.5% and 9.4% in entropy and SNR, respectively. Although percent increase in image quality was reduced when images were compared to initial auto-contrasted CSLO images, the final image quality was improved when auto-contrasting occurred prior to polarimetry calculations for max SNR and max entropy images. Quantitative values of retardance could not be found due to physical constraints in the CSLM that did not allow for characterization of its polarization properties and vibrational noise. Mueller matrix polarimetry used to find the retardance image of a malaria infected retina sample did yield visualization of hemozoin within the vessel but only qualitatively. In conclusion, improvements in the acquisition and registration of CSLO images were successful in leading to considerably shorter experimentation and processing times. In terms of polarimetric image quality improvement techniques, when compared to the best CSLO image. A large proportion of the improvement was in fact due to partially or completely stretching the pixel values across the dynamic range of the images within the algorithm of each technique. However, in general the image quality was still improved by the Mueller matrix reconstruction techniques using both entropy and SNR to generate the CSLO retinal images and the CSLM imaged malaria infected sample. In the malaria sample, retinal blood vessel visualization was also qualitatively improved. The images yielded from Mueller matrix polarimetry applied to a malaria infected retinal sample localized hemozoin within the blood vessel, but a quantitative image of the phase retardance could not be achieved.
Download or read book Ryan s Retina E Book written by Charles P. Wilkinson and published by Elsevier Health Sciences. This book was released on 2017-04-17 with total page 2893 pages. Available in PDF, EPUB and Kindle. Book excerpt: The undisputed gold standard text in the field, Ryan's Retina is your award-winning choice for the most current, authoritative information on new technologies, surgical approaches, scientific advances and diagnostic and therapeutic options for retinal diseases and disorders. Packed with timely updates throughout, new illustrations, and a dedicated team of editors who extend Dr. Ryan’s legacy in retina, this outstanding 6th Edition is a must-have reference for retinal specialists, ophthalmologists, and fellows in training. Offers the most comprehensive content available on retina, balancing the latest scientific research and clinical correlations, covering everything you need to know on retinal diagnosis, treatment, development, structure, function, and pathophysiology. Provides a truly global perspective from five highly esteemed section editors and more than 350 other world authorities from across Europe, Asia, Australasia, and the Americas. Bullets Includes new chapters on widefield imaging, intraoperative OCT imaging, medical management of diabetes mellitus and age-related macular degeneration, and senile retinoschisis. Includes more than 1,150 brand-new illustrations, scans, and photographs throughout. Covers the explosion of new imaging options across optical coherence tomography (OCT), fundus imaging, and autofluorescence imaging, including a greatly expanded OCT imaging chapter that features crucial information on OCT-Angiography (OCT-A). Presents new pharmacotherapy data and the latest approaches in anti-VEGF therapy for age-related macular degeneration, diabetic retinopathy, and venous occlusive disease. Features an expanded online video library highlighting the latest surgical techniques and new coverage of complications of vitreoretinal surgery. Contains thorough content updates in every area of retina, including advanced imaging technologies, gene therapy, inflammation and immune responses, white dot syndromes, epigenetic mechanisms, transplantation frontiers to improve retinal function, macular hole, myopic eye disease, ocular trauma, drug delivery to the posterior segment, advances in macular surgery, vitrectomy and complex retinal detachment, tumors, and retinal genetics and biology. Expert ConsultTM eBook version included with purchase. This enhanced eBook experience allows you to search all of the text, figures, Q&As, and references from the book on a variety of devices.
Download or read book Digital Image Processing for Ophthalmology written by Xiaolu Zhu and published by Springer Nature. This book was released on 2022-05-31 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundus images of the retina are color images of the eye taken by specially designed digital cameras. Ophthalmologists rely on fundus images to diagnose various diseases that affect the eye, such as diabetic retinopathy and retinopathy of prematurity. A crucial preliminary step in the analysis of retinal images is the identification and localization of important anatomical structures, such as the optic nerve head (ONH), the macula, and the major vascular arcades. Identification of the ONH is an important initial step in the detection and analysis of the anatomical structures and pathological features in the retina. Different types of retinal pathology may be detected and analyzed via the application of appropriately designed techniques of digital image processing and pattern recognition. Computer-aided analysis of retinal images has the potential to facilitate quantitative and objective analysis of retinal lesions and abnormalities. Accurate identification and localization of retinal features and lesions could contribute to improved diagnosis, treatment, and management of retinopathy. This book presents an introduction to diagnostic imaging of the retina and an overview of image processing techniques for ophthalmology. In particular, digital image processing algorithms and pattern analysis techniques for the detection of the ONH are described. In fundus images, the ONH usually appears as a bright region, white or yellow in color, and is indicated as the convergent area of the network of blood vessels. Use of the geometrical and intensity characteristics of the ONH, as well as the property that the ONH represents the location of entrance of the blood vessels and the optic nerve into the retina, is demonstrated in developing the methods. The image processing techniques described in the book include morphological filters for preprocessing fundus images, filters for edge detection, the Hough transform for the detection of lines and circles, Gabor filters to detect the blood vessels, and phase portrait analysis for the detection of convergent or node-like patterns. Illustrations of application of the methods to fundus images from two publicly available databases are presented, in terms of locating the center and the boundary of the ONH. Methods for quantitative evaluation of the results of detection of the ONH using measures of overlap and free-response receiver operating characteristics are also described. Table of Contents: Introduction / Computer-aided Analysis of Images of the Retina / Detection of Geometrical Patterns / Datasets and Experimental Setup / Detection of the\\Optic Nerve Head\\Using the Hough Transform / Detection of the\\Optic Nerve Head\\Using Phase Portraits / Concluding Remarks
Download or read book Automated Delineation and Quantitative Analysis of Blood Vessels in Retinal Fundus Image written by Xiayu Xu and published by . This book was released on 2012 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Automated fundus image analysis plays an important role in the computer aided diagnosis of ophthalmologic disorders. A lot of eye disorders, as well as cardiovascular disorders, are known to be related with retinal vasculature changes. Many studies has been done to explore these relationships. However, most of the studies are based on limited data obtained using manual or semi-automated methods due to the lack of automated techniques in the measurement and analysis of retinal vasculature. In this thesis, a fully automated retinal vessel width measurement technique is proposed. This novel method models the accurate vessel boundary delineation problem in two-dimension into an optimal surface segmentation problem in threedimension. Then the optimal surface segmentation problem is transformed into finding a minimum-cost closed set problem in a vertex-weighted geometric graph. The problem is modeled differently for straight vessel and for branch point because of the different conditions in straight vessel and in branch point. Furthermore, many of the retinal image analysis needs the location of the optic disc and fovea as a prerequisite information, for example, in the analysis of the relationship between vessel width and the distance to the optic disc. Hence, a simultaneous optic disc and fovea detection method is presented, which includes a two-step classification of three classes. The major contributions of this thesis include: 1) developing a fully automated vessel width measurement technique for retinal blood vessels, 2) developing a simultaneous optic disc and fovea detection method, 3) validating the methods using multiple datasets, and 4) applying the proposed methods in multiple retinal vasculature analysis studies.
Download or read book Ryan s Retinal Imaging and Diagnostics E Book written by Stephen J. Ryan and published by Elsevier Health Sciences. This book was released on 2013-08-13 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: Access all of the latest advances in imaging techniques of the retina and posterior segment on your favorite eReader with Ryan's Retinal Imaging and Diagnostics eBook. 12 chapters from the landmark reference Retina, 5th Edition offer the foundations to better understand, apply, and optimize new and emerging retinal imaging technologies. Examine and evaluate the newest diagnostic technologies and approaches that are changing the management of retinal disease, including future imaging technologies which will soon become the standard. Put the very latest diagnostic imaging methods to work in your practice, including optical coherence tomography (OCT), fluoroscein angiography, indocyanine angiography autofluorescence imaging, ophthalmic ultrasound and more. Benefit from the extensive knowledge and experience of esteemed editor and ophthalmologist, the late Dr. Stephen Ryan, and a truly global perspective from the world authorities. Consult this title on your favorite e-reader, conduct rapid searches, and adjust font sizes for optimal readability. Compatible with Kindle®, nook®, and other popular devices.
Download or read book Optimising the Clinical Analysis of Retinal Image Quality in the Human Eye written by Alejandro Cerviño Expósito and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
