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Medical Imaging 1997 Conference on Image Perception

作者： Lee, HC Daly, S VanMetter, RL Eastman Kodak Co. (United States) Sharp Labs of America (United States)

ISBN: (纸本)0819424471

Radiographic tone scale can be optimized for visual perception by mapping equal log-exposure difference in the transmitted radiation field to equal discriminable brightness difference in the displayed image. The mapping will render objects equally visible independent of its exposure level and background. This visually optimized tone scale can be readily achieved in computed radiography. It can also be applied to the conventional screen/film system to provide an ideal aim curve for screen/film design. One of the key components in the construction of such a tone scale curve is the function that relates the physical luminance to the perceptual brightness. It is well known that the perceived brightness is a function of the viewing condition. By comparing the predicted brightness differences from the various brightness models, we found that the Michaelis-Menten function provides a visual tone scale that significantly improves the visibility of details in the high density regions over that produced by existing screen/film systems. Based on the basic visual tone scale, we parameterize the curve shapes at the toe and the shoulder, and thus obtain a family of tone scale curves for computed radiography. The toe and shoulder shapes can be customized for different examination types for achieving the best rendition under the constraints of the limited dynamic range of the output display and the minimum required image contrast.

关键词： brightness model tone scale radiology digital radiography screen/film system visual optimization

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An overview of the visual optimization tools in JPEG 2000

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2002年第1期17卷 85-104页

作者： Zeng, WJ Daly, S Lei, SM Sharp Labs Amer Camas WA 98607 USA

The human visual system plays a key role in the final perceived quality of the compressed images. It is therefore desirable to allow system designers and users to take advantage of the current knowledge of visual perception and models in a compression system. In this paper, we review the various tools in JPEG 2000 that allow its users to exploit many properties of the human visual system such as spatial frequency sensitivity, color sensitivity, and the visual masking effects, We show that the visual tool sets in JPEG 2000 are much richer than what is achievable in JPEG, where only spatially invariant frequency weighting can be exploited. As a result, the visually optimized JPEG 2000 images can usually have much better visual quality than the visually optimized JPEG images at the same bit rates. Some visual comparisons between different visual optimization tools, as well as some visual comparisons between JPEG 2000 and JPEG, will be shown. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： visual optimization wavelet compression JPEG 2000 standard perceptual model visual masking frequency sensitivity

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Interactive visual optimization and Analysis for RFID Benchmarking

Interactive Visual Optimization and Analysis for RFID Benchm...

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IEEE Information visualization Conference/IEEE visualization Conference

作者： Wu, Yingcai Chung, Ka-Kei Qu, Huamin Yuan, Xiaoru Cheung, S. C. Hong Kong Univ Sci & Technol Dept Comp Sci & Engn Kowloon Hong Kong Peoples R China Peking Univ Minist Educ Key Lab Machine Percept Beijing 100871 Peoples R China Peking Univ Sch EECS Beijing 100871 Peoples R China

Radio frequency identification (RFID) is a powerful automatic remote identification technique that has wide applications. To facilitate RFID deployment, an RFID benchmarking instrument called alpha Gate has been invented to identify the strengths and weaknesses of different RFID technologies in various environments. However, the data acquired by alpha Gate are usually complex time-varying multidimensional 3D volumetric data, which are extremely challenging for engineers to analyze. In this paper, we introduce a set of visualization techniques, namely, parallel coordinate plots, orientation plots, a visual history mechanism, and a 3D spatial viewer, to help RFID engineers analyze benchmark data visually and intuitively. With the techniques, we further introduce two workflow procedures (a visual optimization procedure for finding the optimum reader antenna configuration and a visual analysis procedure for comparing the performance and identifying the flaws of RFID devices) for the RFID benchmarking, with focus on the performance analysis of the alpha Gate system. The usefulness and usability of the system are demonstrated in the user evaluation.

关键词： RFID visualization visual analytics visual optimization

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visual optimization analysis on e-commence of Wenzhou Hongwei commerce and trade

Visual optimization analysis on e-commence of Wenzhou Hongwe...

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2017 6th International Conference on Advanced Materials and Computer Science(ICAMCS 2017)

作者： ZhiLiang Xia Wenzhou Vocational ＆ Technical College

This paper mainly introduces art design of e-commerce enterprises and improvement measures based on analysis of shop pages of Wenzhou Hongwei commerce and *** it introduces the concept and main duty of art designer in e-commerce enterprises,analyzes shop pages of Wenzhou Hongwei commerce and trade daily necessities company,and put forward improvement countermeasures.

关键词： E-commerce Art designer visual optimization

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Interactive visual optimization and Analysis for RFID Benchmarking

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IEEE TRANSACTIONS ON visualIZATION AND COMPUTER GRAPHICS 2009年第6期15卷 1335-1342页

关键词： RFID visualization visual analytics visual optimization

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Application of Virtual Reality Technology in visual optimization of Graphic Advertising Vision

Application of Virtual Reality Technology in Visual Optimiza...

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作者： Liu Depeng Suzhou Industrial Park Institute of Vocational Technology

In today's form, graphic advertising visual design is an important medium form in modern design. And with the rapid development of information technology, virtual reality technology has been applied as a derivative in many fields. Graphical visual optimization has been more perfectly presented after the introduction of virtual reality technology. Based on the concept of virtual reality technology, this paper makes a deep discussion on the representation and value of virtual reality technology in visual advertising visual optimization. It is expected that virtual reality technology can be applied to advertising visual optimization in a wider range.

关键词： Virtual reality Print advertising visual optimization Expression

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Better constraints of imperceptibility, better adversarial examples in the text

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INTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS 2022年第6期37卷 3440-3459页

作者： Wang, Wenqi Wang, Lina Wang, Run Ye, Aoshuang Ke, Jianpeng Wuhan Univ Sch Cyber Sci & Engn Key Lab Aerosp Informat Secur & Trusted Comp Minist Educ Wuhan 430072 Peoples R China

State-of-the-art adversarial attacks in the text domain have shown their power to induce machine learning models to produce abnormal outputs. The samples generated in these attacks have three important attributes: attack ability, transferability, and imperceptibility. However, compared with the other two attributes, the imperceptibility of adversarial examples has not been well investigated. Unlike the pixel-level perturbations in images, adversarial perturbations in the text are usually traceable, reflecting changes in characters, words, or sentences. The generation of imperceptible samples in texts is more difficult than in images. Therefore, how to constrain adversarial perturbations added in the text is a crucial step to construct more natural adversarial texts. Unfortunately, recent studies merely select measurements to constrain the added adversarial perturbations, but none of them explain where these measurements are suitable, which one is better, and how they perform in different kinds of adversarial attacks. In this paper, we fill this gap by comparing the performance of these metrics in various attacks. Furthermore, we propose a stricter constraint for word-level attacks to obtain more imperceptible samples. It is also helpful to enhance existing word-level attacks for adversarial training.

关键词： adversarial texts imperceptibility measurements semantic and visual similarity visual optimization

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Minimizing the perceptual impact of visual distortion in scalable wavelet compressed video

Minimizing the perceptual impact of visual distortion in sca...

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IEEE International Conference on Image Processing (ICIP 2006)

作者： Leung, Raymond Taubman, David Univ New S Wales Sydney NSW Australia

ISBN: (纸本)9781424404810

This paper considers the efficacy of a class of intra-channel contrast masking models and proposes a simple extension to increase their effectiveness in capturing perceptual diversity in complex stimuli. "Perceptual diversity" encapsulates the idea that our perceptual response to visual distortion varies, depending not only on where quantization errors occur, but also how they coincide with structural elements that constitute a video frame. We offer a fresh perspective on perceptual modeling and identify factors that limit visual optimization performance. We find that the perceptual impact of suprathreshold visual distortion cannot be fully assessed based on contrast alone. In this work, we introduce a context-adaptive masking slope to complement the basic functions of our perceptual model. This versatile feature allows visual sensitivity to be emphasized, or suppressed, in a manner which reflects the perceptual significance of local distortion in a video. Finally, we propose a visual optimization strategy for embedded video coding based on a perceptual mapping and distortion scaling approach. This technique mitigates the noise shaping effects due to motion-compensated temporal synthesis.

关键词： human visual system video coding image edge analysis perceptual modeling visual optimization wavelet artifacts

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Color halftoning by indexing the visual-optimized dot profiles

Color halftoning by indexing the visual-optimized dot profil...

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EUROPTO Conference on Electronic Imaging - Processing, Printing, and Publishing in Color

作者： Yoo, YJ Park, HW Korea Advanced Institute of Science and Technology (South Korea)

ISBN: (纸本)0819428612

A new halftoning method for color image is proposed. The proposed algorithm is very simple to implement the halftoning in hardware and software, which indexes the image pixel values to a binary database as proposed by Sullivan et al. The database is a set of dot profiles representing the corresponding gray levels. The dot profiles are sequentially generated from a visual-optimized seed pattern which is well-distributed by contrast sensitivity function (CSF), in order that the dot profiles have the visual-optimality as well as correlation between dot profiles of ail gray levels. Circular convolution technique is used for generating the dot profiles so that the periodic blocking artifacts can be reduced. The proposed color halftoning method uses one database which is shared for all color components and can be directly used for monochrome halftoning, but each color component has different indexing scheme with a circularly shifted indexing to reduce the correlation between dot profiles of color components. The simple structure and small memory requirement of the proposed halftoning method make the processing time fast. The halftone image quality of the proposed method is better than that of ordered dither.

关键词： color halftoning contrast sensitivity function (CSF) halftoning database dot profiles visual optimization circular convolution circularly shifted indexing

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SCALABLE VIDEO COMPRESSION WITH OPTIMIZED visual PERFORMANCE AND RANDOM ACCESSIBILITY

SCALABLE VIDEO COMPRESSION WITH OPTIMIZED VISUAL PERFORMANCE...

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作者： Raymond Wing-Fai Leung University of New South Wales

学位级别：博士

This thesis is concerned with maximizing the coding efficiency, random accessibility and visual performance of scalable compressed video. The unifying theme behind this work is the use of finely embedded localized coding structures, which govern the extent to which these goals may be jointly achieved. The first aspect of the thesis focuses on scalable volumetric image compression. We investigate 3D transform and coding techniques which exploit inter slice statistical redundancies without compromising slice accessibility. Our study shows that motion-compensated temporal discrete wavelet transform practically achieves an upper bound to the compression efficiency of slice transforms. From a video coding perspective, we evaluate the effectiveness of utilizing context information from neighboring frames. We find that most of the coding gain is attributed to o setting the learning penalty in adaptive arithmetic coding through 3D code block extension, rather than inter-frame context modeling. The second aspect of this thesis examines random accessibility. Accessibil ity refers to the ease with which a region is accessed from a compressed video bitstream. This is analyzed in terms of the smallest subset of subband coe-ficients required for reconstructing a region of interest in a video; subject to the spatiotemporal constraints imposed by code blocks. A key issue that we investi gate is the fundamental implications of motion compensation for random access e ciency and the compression performance of scalable interactive video. We demonstrate that the inclusion of motion compensation operators within the lift ing steps of a temporal subband transform incurs a random access penalty, which varies depending on the characteristics of the motion field. The final aspect of this thesis aims to improve the perceptual quality of scalable wavelet-compressed video. The objective is to make compression artefacts appear as perceptually uniform as possible, so as to minimize the visual imp

关键词： scalable video compression visual optimization perceptual quality perceived distortion region of interest random access efficiency wavelet artefacts temporal subband synthesis perceptual mapping localized embedded coding structures EBCOT post-c

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