Visual Quality Assessment and Enhancement for Natural Images PDF Download

Author: SURYA. JOSHI PRAKASH (PIYUSH.)
Publisher: World Scientific Publishing Company
ISBN: 9789811257285
Category : Computers
Languages : en
Pages : 0

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Book Description
Digital images play a significant role in representing useful information; however, they may get distorted while passing through several operational stages, such as image acquisition, compression, transmission, processing, and reconstruction. Similarly, during the transmission of images, some data may be lost and the quality of the image may degrade due to bandwidth limitation. The use of distorted images in any application compromises its performance; and therefore, the identification and quantification of degradation become key issues to address in restoring the distorted images.This book covers different quality assessment techniques for natural images. It further discusses image enhancement techniques that are based on estimated quality. This book presents image quality assessment techniques for different distortions, such as poor contrast, poor illumination, noise and artifacts in deblocked images. Also presented are quality-aware techniques for image enhancement for different distortions.Review and objective questions (with answers) for each chapter will be available online as part of the supplementary material.

Author: Ke Gu
Publisher: Springer Nature
ISBN: 9811933472
Category : Computers
Languages : en
Pages : 256

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Book Description
This book provides readers with a comprehensive review of image quality assessment technology, particularly applications on screen content images, 3D-synthesized images, sonar images, enhanced images, light-field images, VR images, and super-resolution images. It covers topics containing structural variation analysis, sparse reference information, multiscale natural scene statistical analysis, task and visual perception, contour degradation measurement, spatial angular measurement, local and global assessment metrics, and more. All of the image quality assessment algorithms of this book have a high efficiency with better performance compared to other image quality assessment algorithms, and the performance of these approaches mentioned above can be demonstrated by the results of experiments on real-world images. On the basis of this, those interested in relevant fields can use the results obtained through these quality assessment algorithms for further image processing. The goal of this book is to facilitate the use of these image quality assessment algorithms by engineers and scientists from various disciplines, such as optics, electronics, math, photography techniques and computation techniques. The book can serve as a reference for graduate students who are interested in image quality assessment techniques, for front-line researchers practicing these methods, and for domain experts working in this area or conducting related application development.

Author: Yong Ding
Publisher: Springer
ISBN: 3662564971
Category : Technology & Engineering
Languages : en
Pages : 278

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Book Description
Image quality assessment (IQA) is an essential technique in the design of modern, large-scale image and video processing systems. This book introduces and discusses in detail topics related to IQA, including the basic principles of subjective and objective experiments, biological evidence for image quality perception, and recent research developments. In line with recent trends in imaging techniques and to explain the application-specific utilization, it particularly focuses on IQA for stereoscopic (3D) images and medical images, rather than on planar (2D) natural images. In addition, a wealth of vivid, specific figures and formulas help readers deepen their understanding of fundamental and new applications for image quality assessment technology. This book is suitable for researchers, clinicians and engineers as well as students working in related disciplines, including imaging, displaying, image processing, and storage and transmission. By reviewing and presenting the latest advances, and new trends and challenges in the field, it benefits researchers and industrial R&D engineers seeking to implement image quality assessment systems for specific applications or design/optimize image/video processing algorithms.

Author: Hojatollah Yeganeh
Publisher:
ISBN:
Category :
Languages : en
Pages : 127

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Book Description
In recent years, image and video signals have become an indispensable part of human life. There has been an increasing demand for high quality image and video products and services. To monitor, maintain and enhance image and video quality objective image and video quality assessment tools play crucial roles in a wide range of applications throughout the field of image and video processing, including image and video acquisition, communication, interpolation, retrieval, and displaying. A number of objective image and video quality measures have been introduced in the last decades such as mean square error (MSE), peak signal to noise ratio (PSNR), and structural similarity index (SSIM). However, they are not applicable when the dynamic range or spatial resolution of images being compared is different from that of the corresponding reference images. In this thesis, we aim to tackle these two main problems in the field of image quality assessment. Tone mapping operators (TMOs) that convert high dynamic range (HDR) to low dynamic range (LDR) images provide practically useful tools for the visualization of HDR images on standard LDR displays. Most TMOs have been designed in the absence of a well-established and subject-validated image quality assessment (IQA) model, without which fair comparisons and further improvement are difficult. We propose an objective quality assessment algorithm for tone-mapped images using HDR images as references by combining 1) a multi-scale signal fidelity measure based on a modified structural similarity (SSIM) index; and 2) a naturalness measure based on intensity statistics of natural images. To evaluate the proposed Tone-Mapped image Quality Index (TMQI), its performance in several applications and optimization problems is provided. Specifically, the main component of TMQI known as structural fidelity is modified and adopted to enhance the visualization of HDR medical images on standard displays. Moreover, a substantially different approach to design TMOs is presented, where instead of using any pre-defined systematic computational structure (such as image transformation or contrast/edge enhancement) for tone-mapping, we navigate in the space of all LDR images, searching for the image that maximizes structural fidelity or TMQI. There has been an increasing number of image interpolation and image super-resolution (SR) algorithms proposed recently to create images with higher spatial resolution from low-resolution (LR) images. However, the evaluation of such SR and interpolation algorithms is cumbersome. Most existing image quality measures are not applicable because LR and resultant high resolution (HR) images have different spatial resolutions. We make one of the first attempts to develop objective quality assessment methods to compare LR and HR images. Our method adopts a framework based on natural scene statistics (NSS) where image quality degradation is gauged by the deviation of its statistical features from NSS models trained upon high quality natural images. In particular, we extract frequency energy falloff, dominant orientation and spatial continuity statistics from natural images and build statistical models to describe such statistics. These models are then used to measure statistical naturalness of interpolated images. We carried out subjective tests to validate our approach, which also demonstrates promising results. The performance of the proposed measure is further evaluated when applied to parameter tuning in image interpolation algorithms.

Author: Alan C. Bovik
Publisher: Academic Press
ISBN: 0080533612
Category : Technology & Engineering
Languages : en
Pages : 1429

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Book Description
55% new material in the latest edition of this “must-have for students and practitioners of image & video processing! This Handbook is intended to serve as the basic reference point on image and video processing, in the field, in the research laboratory, and in the classroom. Each chapter has been written by carefully selected, distinguished experts specializing in that topic and carefully reviewed by the Editor, Al Bovik, ensuring that the greatest depth of understanding be communicated to the reader. Coverage includes introductory, intermediate and advanced topics and as such, this book serves equally well as classroom textbook as reference resource. • Provides practicing engineers and students with a highly accessible resource for learning and using image/video processing theory and algorithms • Includes a new chapter on image processing education, which should prove invaluable for those developing or modifying their curricula • Covers the various image and video processing standards that exist and are emerging, driving today’s explosive industry • Offers an understanding of what images are, how they are modeled, and gives an introduction to how they are perceived • Introduces the necessary, practical background to allow engineering students to acquire and process their own digital image or video data • Culminates with a diverse set of applications chapters, covered in sufficient depth to serve as extensible models to the reader’s own potential applications About the Editor... Al Bovik is the Cullen Trust for Higher Education Endowed Professor at The University of Texas at Austin, where he is the Director of the Laboratory for Image and Video Engineering (LIVE). He has published over 400 technical articles in the general area of image and video processing and holds two U.S. patents. Dr. Bovik was Distinguished Lecturer of the IEEE Signal Processing Society (2000), received the IEEE Signal Processing Society Meritorious Service Award (1998), the IEEE Third Millennium Medal (2000), and twice was a two-time Honorable Mention winner of the international Pattern Recognition Society Award. He is a Fellow of the IEEE, was Editor-in-Chief, of the IEEE Transactions on Image Processing (1996-2002), has served on and continues to serve on many other professional boards and panels, and was the Founding General Chairman of the IEEE International Conference on Image Processing which was held in Austin, Texas in 1994. * No other resource for image and video processing contains the same breadth of up-to-date coverage * Each chapter written by one or several of the top experts working in that area * Includes all essential mathematics, techniques, and algorithms for every type of image and video processing used by electrical engineers, computer scientists, internet developers, bioengineers, and scientists in various, image-intensive disciplines

Author: Zhou Wang
Publisher: Springer Nature
ISBN: 3031022386
Category : Technology & Engineering
Languages : en
Pages : 146

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Book Description
This Lecture book is about objective image quality assessment—where the aim is to provide computational models that can automatically predict perceptual image quality. The early years of the 21st century have witnessed a tremendous growth in the use of digital images as a means for representing and communicating information. A considerable percentage of this literature is devoted to methods for improving the appearance of images, or for maintaining the appearance of images that are processed. Nevertheless, the quality of digital images, processed or otherwise, is rarely perfect. Images are subject to distortions during acquisition, compression, transmission, processing, and reproduction. To maintain, control, and enhance the quality of images, it is important for image acquisition, management, communication, and processing systems to be able to identify and quantify image quality degradations. The goals of this book are as follows; a) to introduce the fundamentals of image quality assessment, and to explain the relevant engineering problems, b) to give a broad treatment of the current state-of-the-art in image quality assessment, by describing leading algorithms that address these engineering problems, and c) to provide new directions for future research, by introducing recent models and paradigms that significantly differ from those used in the past. The book is written to be accessible to university students curious about the state-of-the-art of image quality assessment, expert industrial R&D engineers seeking to implement image/video quality assessment systems for specific applications, and academic theorists interested in developing new algorithms for image quality assessment or using existing algorithms to design or optimize other image processing applications.

Author: Omar Abdulrahman Alaql
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The last decade has witnessed great advances in digital images. Massive numbers of digital images are being captured by mobile digital cameras due to the increasing popularity of mobile imaging devices. These images are subjected to many processing stages during storing, transmitting, or sharing over a network connection. Unfortunately, these processing stages could potentially add visual degradation to original image. These degradations reduce the perceived visual quality which leads to an unsatisfactory experience for human viewers. Therefore, Image Quality Assessment (IQA) has become a topic of high interest and intense research over the last decade. The aim of IQA is to automatically assess image quality in agreement with human judgments.This dissertation mainly focuses on the most challenging category of IQA - general- purpose No-Reference Image Quality Assessment (NR-IQA), where the goal is to assess the quality of images without information about the reference images and without prior knowledge about the types of distortions in the tested image. This dissertation contributes to the research of image quality assessment by proposing three novel approaches for NR- IQA and one model for image distortions classification. First, we propose improvements in image distortions classification by introducing a training model based on new features collection. Second, we propose a NR-IQA technique, which utilizes our improvement in the classification model, and based on a hypothesis that an effective combination of image features can be used to develop efficient NR-IQA approaches. Third, a NR-IQA technique is proposed based on Natural Scene Statistics (NSS) by finding the distance between the natural images and the distorted images in 3D dimensional space. Forth, a novel NR-IQA approach is presented, by utilizing multiple Deep Belief Networks (DBNs) with multiple regression models. We have evaluated the performance of the proposed and some existing models on a fair basis. The obtained results show that our models give better results and yield a significant improvement.

Author: Chenwei Deng
Publisher: Springer
ISBN: 3319103687
Category : Technology & Engineering
Languages : en
Pages : 311

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Book Description
This book provides comprehensive coverage of the latest trends/advances in subjective and objective quality evaluation for traditional visual signals, such as 2D images and video, as well as the most recent challenges for the field of multimedia quality assessment and processing, such as mobile video and social media. Readers will learn how to ensure the highest storage/delivery/ transmission quality of visual content (including image, video, graphics, animation, etc.) from the server to the consumer, under resource constraints, such as computation, bandwidth, storage space, battery life, etc.

Author: Anush Krishna Moorthy
Publisher:
ISBN:
Category :
Languages : en
Pages : 408

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Book Description
Progress in multimedia technologies has resulted in a plethora of services and devices that capture, compress, transmit and display audiovisual stimuli. Humans -- the ultimate receivers of such stimuli -- now have access to visual entertainment at their homes, their workplaces as well as on mobile devices. With increasing visual signals being received by human observers, in the face of degradations that occur to due the capture, compression and transmission processes, an important aspect of the quality of experience of such stimuli is the \emph{perceived visual quality}. This dissertation focuses on algorithm development for assessing such visual quality of natural images, without need for the `pristine' reference image, i.e., we develop computational models for no-reference image quality assessment (NR IQA). Our NR IQA model stems from the theory that natural images have certain statistical properties that are violated in the presence of degradations, and quantifying such deviations from \emph{naturalness} leads to a blind estimate of quality. The proposed modular and easily extensible framework is distortion-agnostic, in that it does not need to have knowledge of the distortion afflicting the image (contrary to most present-day NR IQA algorithms) and is not only capable of quality assessment with high correlation with human perception, but also is capable of identifying the distortion afflicting the image. This additional distortion-identification, coupled with blind quality assessment leads to a framework that allows for blind general-purpose image repair, which is the second major contribution of this dissertation. The blind general-purpose image repair framework, and its exemplar algorithm described here stem from a revolutionary perspective on image repair, where the framework does not simply attempt to ameliorate the distortion in the image, but to ameliorate the distortion, so that visual quality at the output is maximized. Lastly, this dissertation describes a large-scale human subjective study that was conducted at UT to assess human behavior and opinion on visual quality of videos when viewed on mobile devices. The study lead to a database of 200 distorted videos, which incorporates previously studied distortions such as compression and wireless packet-loss, and also dynamically varying distortions that change as a function of time, such as frame-freezes and temporally varying compression rates. This study -- the first of its kind -- involved over 50 human subjects and resulted in 5,300 summary subjective scores and time-sampled subjective traces of quality for multiple displays. The last part of this dissertation analyzes human behavior and opinion on time-varying video quality, opening up an extremely interesting and relevant field for future research in the area of quality assessment and human behavior.

Author: Di Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages :

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