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Joint Meeting of the 14th International Workshop on Systems, Signals and Image Processing/EURASIP Conference Focused on Speech and Image Processing, Multimedia Communications and Services

作者： Ulacha, G. Stasinski, R. Tech Univ Szczecin Dept Comp Sci Zolmierska 49 Szczecin Poland Poznan Univ Tech Dept Elect & Telecommun PL-60965 Poznan Poland

ISBN: (纸本)9789612480363

The new predictor-based lossless image coding technique is described in the paper. The technique is optimized for coding of images containing large areas of regular texture, and indeed, it is shown that in such cases it is even better than preprocessing stages of renown coding methods, like CALIC or LOCO-I. The technique is intended to be used as a specialized part of predictor blending method.

关键词： lossless coding predictor blending texture coding

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coding of dynamic texture on 3D scenes 8th

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8th International Conference on Computer Analysis of Images and Patterns (CAIP 99)

作者： DeKnuydt, B Desmet, S Van Eycken, L Van Gool, L PSI VISICS B-3001 Heverlee Belgium

ISBN: (纸本)3540663665

As cheap and powerful 3D render engines become commonplace, demand for nearly realistic 3D scenes is increasing. Besides more detailed geometric and texture information, this presupposes the ability to map dynamic textures. This is obviously needed to model movies, computer and TV screens, but also for example the landscape as seen from inside a moving vehicle, or shadow and lighting effects that are not modeled separately. Downloading the complete scene to the user, before letting him interact with the scene, becomes very unpractical and inefficient with huge scenes. If the texture is not a canned sequence, but a stream, it is altogether impossible. Often a back channel is available, which allows on demand downloading so the user can start interacting with the scene immediately. This can save considerable amounts of bandwidth. Specifically for dynamic texture, if we know the viewpoint of the user (or several users), we can code the texture taking into account the viewing conditions, i.e. coding and transmitting each part of the texture with the required resolution only. Applications that would benefit from view-dependent coding of dynamic textures, include (but are not limited to) multiplayer 3D games, walkthroughs of dynamic constructions or scenes and 3D simulations of dynamic systems. In this paper, a scheme based on an adapted OLA (Optimal Level Allocation) video codec is shown. Important data rate reductions can be achieved with it.

关键词： texture coding dynamic texture

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Online joint palmprint and palmvein verification

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EXPERT SYSTEMS WITH APPLICATIONS 2011年第3期38卷 2621-2631页

作者： Zhang, David Guo, Zhenhua Lu, Guangming Zhang, Lei Liu, Yahui Zuo, Wangmeng Hong Kong Polytech Univ Biometr Res Ctr Kowloon Hong Kong Peoples R China Tsinghua Univ Grad Sch Shenzhen 518057 Guangdong Peoples R China Harbin Inst Technol Shenzhen Grad Sch Shenzhen Guangdong Peoples R China Harbin Inst Technol Sch Comp Sci & Technol Harbin 150006 Heilongjiang Peoples R China

As a unique and reliable biometric characteristic, palmprint verification has achieved a great success. However, palmprint alone may not be able to meet the increasing demand of highly accurate and robust biometric systems. Recently, palmvein, which refers to the palm feature under near-infrared spectrum, has been attracting much research interest. Since palmprint and palmvein can be captured simultaneously by using specially designed devices, the joint use of palmprint and palmvein features can effectively increase the accuracy, robustness and anti-spoof capability of palm based biometric techniques. This paper presents an online personal verification system by fusing palmprint and palmvein information. Considering that the palmvein image quality can vary much, a dynamic fusion scheme which is adaptive to image quality is developed. To increase the anti-spoof capability of the system, a liveness detection method based on the image property is proposed. A comprehensive database of palmprint-palmvein images was established to verify the proposed system, and the experimental results demonstrated that since palmprint and palmvein contain complementary information, much higher accuracy could be achieved by fusing them than using only one of them. In addition, the whole verification procedure can be completed in 1.2 s, which implies that the system can work in real time. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Biometric authentication Palmprint Palmvein Fusion Liveness detection texture coding Matched filter

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Online personal verification by palmvein image through palmprint-like and palmvein information

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NEUROCOMPUTING 2015年第1期147卷 364-371页

作者： Li, Qin Li, Xiu Guo, Zhenhua You, Jane Shenzhen Inst Informat Technol Sch Software Engn Shenzhen Guangdong Peoples R China Tsinghua Univ Grad Sch Shenzhen Shenzhen 518057 Guangdong Peoples R China Tsinghua Univ Grad Sch Shenzhen Shenzhen Key Lab Broadband Network & Multimedia Shenzhen 518057 Guangdong Peoples R China Nanjing Univ Sci & Technol Key Lab Intelligent Percept & Syst High Dimens In Minist Educ Nanjing Jiangsu Peoples R China Hong Kong Polytech Univ Dept Comp Kowloon Hong Kong Peoples R China

Recently, palmvein recognition has been attracting much research interest. The joint use of palmprint and palmvein features can effectively increase the accuracy, robustness of palm based biometric techniques. And, as it is an inner vessel structure feature, palmveins can increase the anti-spoof and liveness detection capability of a palm based biometric system. However, lack of techniques to separate palmveins from palmprints in one image weakens the anti-spoof and liveness detection capability. This paper presents a novel online personal verification system by fusing palmprint and palmvein information. The proposed system includes: (1) A single camera and single light source to simplify the imaging system and save data collection time;(2) A morphological palmprint erasing technique to increase the accuracy of palmvein segmentation;(3) The fusion of palmprint and palmvein information to further improve the system accuracy. The experimental results demonstrated that since palmprints and palmveins contain complementary information, much higher accuracy could be achieved by fusing them than using only one of them. In addition, the whole verification procedure can be completed within 1 s, which implies that the system can work in real time. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Biometric authentication Palmprint Palmvein Fusion texture coding Matched filter

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A region-based subband coding scheme

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SIGNAL PROCESSING-IMAGE COMMUNICATION 1997年第1-3期10卷 173-200页

作者： Casas, JR Torres, L Department of Signal Theory and Communications Universitat Politècnica de Catalunya Campus Nord UPC edifici D5 c/Gran Capita s/n 08034 Barcelona Spain

This paper describes a region-based subband coding scheme intended for efficient representation of the visual information contained in image regions of arbitrary shape. QMF filters are separately applied inside each region for the analysis and synthesis stages, using a signal-adaptive symmetric extension technique at region borders. The frequency coefficients corresponding to each region are identified over the various subbands of the decomposition, so that the coding steps namely, bit-allocation, quantization and entropy coding - can be performed independently for each region. Region-based subband coding exploits the possible homogeneity of the region contents by distributing the available bit-rate not only in the frequency domain but also in the spatial domain, i.e. among the considered regions. The number of bits assigned to the subbands is optimized region by region for the whole image, by means of a rate-distortion optimization algorithm. Improved compression efficiency is obtained thanks to the local adaptativity of the bit allocation to the spectral contents of the different regions. This compensates for the overhead data spent in the coding of contour information. As the subband coefficients obtained for each region are coded as separate data units, the content-based functionalities required for the future MPEG4 video coding standard can be readily handled. For instance, content-based scalability is possible by simply imposing user-defined constraints to the bit-assignment in some regions. (C) 1997 Elsevier Science B.V.

关键词： image coding video coding subband analysis signal extension region-based bit allocation texture coding

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Parallel H.263 video encoder in normal coding mode

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ELECTRONICS LETTERS 1998年第22期34卷 2109-2110页

作者： Cosmas, JP Paker, Y Pearmain, AJ Univ London Queen Mary & Westfield Coll Dept Elect Engn London E1 4NS England

A parallel H.263 video encoder, which utilises spatial pal allelism, has been modelled using a multi-threaded program. Spatial parallelism is a technique where an image is subdivided into equal parts las far as physically possible) and each part is processed by a separate processor by computing motion and texture coding with all processors each acting on a different part of the image. This method leads to a performance increase, which is roughly in proportion to the number of parallel processors used.

关键词： motion estimation multi-threaded program parallel processors spatial parallelism texture coding multi-threading Image and video coding motion coding equal parts Video signal processing parallel H.263 video encoder image texture video coding Multiprocessing systems normal coding mode parallel processing

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Scalable wavelet coding for synthetic/natural hybrid images

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1999年第2期9卷 244-254页

作者： Sodagar, I Lee, HJ Hatrack, P Zhang, YQ Sarnoff Corp Multimedia Technol Lab Princeton NJ 08512 USA

This paper describes the texture representation scheme adopted for MPEG-4 synthetic/natural hybrid coding (SNHC) of texture maps and images. The scheme is based on the concept of muitiscale zerotree wavelet entropy (MZTE) coding technique, which provides many levels of scalability layers in terms of either spatial resolutions or picture quality. MZTE, with three different modes (single-Q, multi-Q, and bilevel), provides much improved compression efficiency and fine-gradual scalabilities, which are ideal for hybrid coding of texture maps and natural images. The MZTE scheme is adopted as the baseline technique for the visual texture coding profile in both the MPEG-4 video group and SNHC group. The test results are presented in comparison with those coded by the baseline JPEG scheme for different types of input images, MZTE was also rated as one of the top five schemes in terms of compression efficiency in the JPEG2000 November 1997 evaluation, among 27 submitted proposals.

关键词： compression image and video coding JPEG-20001 MPEG-4 texture coding wavelet

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Generating realistic facial expressions with wrinkles for model-based coding

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COMPUTER VISION AND IMAGE UNDERSTANDING 2001年第2期84卷 201-240页

作者： Yin, LJ Basu, A SUNY Binghamton Thomas J Watson Sch Engn & Appl Sci Dept Comp Sci Binghamton NY 13902 USA Univ Alberta Dept Comp Sci Edmonton AB T6G 2H1 Canada

Due to the limitations of current computer graphics technology mimicing realistic facial textures, such as wrinkles, is very difficult. Facial texture updating and compression are crucial to achieving realistic facial animation for low bit rate model-based coding. In this paper, we present a partial texture updating method for realistic facial expression synthesis with facial wrinkles. First, fiducial points on a face are estimated using a color-based deformable template matching method. Second, an extended dynamic mesh matching algorithm is developed for face tracking. Next, textures of interest (TOI) in the potential expressive wrinkles and mouth-eye texture areas are captured by the detected fiducial points. Among the TOI, the so-called active textures or expressive textures are extracted by exploring temporal correlation information. Finally, the entire facial texture is synthesized using the active texture. Compared to the entire texture updating scheme, partially updating and compressing facial textures significantly reduce the computational complexity and bit rates while still producing an acceptable visual quality. Experiments on the video sequences demonstrate the advantage of the proposed algorithm. (C) 2001 Elsevier Science (USA).

关键词： texture coding MPEG4 model-based coding feature detection SNHC

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Advanced Film Grain Noise Extraction and Synthesis for High-Definition Video coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2009年第12期19卷 1717-1729页

作者： Oh, Byung Tae Lei, Shaw-min Kuo, C. -C. Jay Sharp Labs Amer Camas WA 98607 USA Univ So Calif Signal Image Proc Inst Los Angeles CA 90089 USA

A technique for film grain noise extraction, modeling and synthesis is studied and applied to high-definition video coding in this paper. Film grain noise enhances the natural appearance of pictures in high-definition video and should be preserved in coded video. However, the coding of video contents with film grain noise is expensive. In previous art, it was proposed to enhance the coding performance by extracting film grain noise from the input video at the encoder as a preprocessing step, and by resynthesizing and adding it back to the decoded video at the decoder as a postprocessing step. In a novel implementation of this approach, we first remove film grain noise from image/video with a variational denoising approach without distorting its original content. Then, we present a parametric model (consisting of a small set of parameters) to generate film grain noise that is close to the actual one in terms of a couple of observed statistical properties, such as the power spectral density and the crosschannel spectral correlation. Under this framework, the coding gain of denoised video is higher while the visual quality of the final reconstructed video is well preserved. Experimental results are provided to demonstrate the superior performance of the proposed approach.

关键词： Denoising film grain noise image restoration noise synthesis parametric model texture coding texture synthesis total variation

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Analysis and synthesis of textures through the inference of Boolean functions

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SIGNAL PROCESSING 1997年第1期59卷 1-16页

作者： Dominguez, M Torres, L POLITECH UNIV CATALONIA DEPT SIGNAL THEORY & COMMUNBARCELONA 08034SPAIN

This work deals with Boolean functions of non-linear and linear basis. The Boolean random functions of non-linear basis were proposed by Serra (1988, 1989). These functions are generated through a Poisson point process upon which a family of independent functions, called gel functions, are installed. This process of installation consists in taking the Sup (supremum), point to point, of the result of placing the germ functions upon the points of the Poisson process. Boolean functions of linear basis, which are defined and proposed in this paper, are generated in the same manner as the non-linear functions but with a modified installation process. Instead of taking the Sup point to point, the sum point to point is defined. So the process is then equivalent to the convolution of a Poisson train of deltas with a random pulse. The aim of this paper is to analyse textures through these two models, in order to infere their genetics through a given realisation of the process, i.e., to analyse the complete statistics of the germ functions and the density of the associated Poisson process in order to characterise a given texture. Experiments and results are provided which prove that the real textures can be understood as realisations of Boolean random functions (of linear and non-linear basis), and that it has been possible to infere the genetics of unidimensional Boolean random functions of linear basis with the algorithm proposed here. It has also been possible to do it with non-linear Boolean functions but only by imposing two restrictive conditions on the genetics of the realisation. (C) 1997 Elsevier Science B.V.

关键词： texture analysis texture coding Boolean functions infinitely divisible distributions

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