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19th International Conference on Digital Signal Processing (DSP)

作者： Naser, Karam Ricordel, Vincent Le Callet, Patrick Univ Nantes LUNAM Univ IRCCyN UMR CNRS 6597 Polytech Nantes F-44306 Nantes 3 France

ISBN: (纸本)9781479946129

textures can often be found in large areas of images and videos. They have different spectral and statistical properties as compared with normal (structural) components. Encoding them with ordinary video coders requires higher bit rate and usually results are unsatisfying in perceived quality. Recently, different perceptual tools have been developed to estimate the perceived quality of textures taking into account models of human visual system. In this paper, we investigate and discuss the practical usability of one of these tools, namely STSIM, as a distortion function for selecting the intra-prediction mode and block partitioning of texture images in HEVC. We experiment few practical implementations to examine its performance compared with default metrics used by HEVC. Experimental results showed that the perceived quality of the decoded textures has been significantly improved specially for stochastic types of textures

关键词： texture coding Perceptual Optimization STSIM

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Optimal bit allocation for joint texture-aware contour-based shape coding and shape-adaptive texture coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2008年第6期18卷 840-844页

作者： Bandyopadhyay, Saurav K. Kondi, Lisimachos P. W&W Comm DSP Res Sunnyvale CA 94086 USA Univ Ioannina Dept Comp Sci GR-45110 Ioannina Greece

In this paper, an operationally optimal joint shape and texture coding algorithm is proposed that uses shape-adaptive texture coding as well as texture-aware shape coding. The solution is optimal in the operational rate distortion sense, i.e, given the coding setup, the solution will guarantee the smallest possible distortion for a given rate. The shape is approximated using polygons or higher order curves. We also consider biasing the cost function to favor horizontal and vertical edges for the case of polygon approximation (biased polygon approximation). The texture is encoded using shape-adaptive discrete cosine transform. or shape-adaptive discrete wavelet transform of the MPEG-4 video codec. A comparison is drawn between the two techniques. Both a fixed-width and a variable-width tolerance band for shape coding are considered. The variable width of the tolerance band is a function of the texture profile, i.e, the width is inversely proportional to the magnitude of the image gradient. Experimental results are presented and conclusions are drawn.

关键词： optimization shape-adaptive discrete cosine transform (SA-DCT) shape-adaptive discrete wavelet transform (SA-DWT) shape coding texture coding

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Multiview depth coding based on combined color/depth segmentation

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2012年第1期23卷 42-52页

作者： Ruiz-Hidalgo, J. Morros, J. R. Aflaki, P. Calderero, F. Marques, F. Univ Politecn Cataluna Dept Signal Theory & Commun ES-08034 Barcelona Spain Tampere Univ Technol FIN-33101 Tampere Finland Univ Pompeu Fabra Barcelona 08018 Spain

In this paper, a new coding method for multiview depth video is presented. Considering the smooth Structure and sharp edges of depth maps, a segmentation based approach is proposed. This allows further preserving the depth contours thus introducing fewer artifacts in the depth perception of the video. To reduce the cost associated with partition coding, an approximation of the depth partition is built using the decoded color view segmentation. This approximation is refined by sending some complementary information about the relevant differences between color and depth partitions. For coding the depth content of each region, a decomposition into orthogonal basis is used in this paper although similar decompositions may be also employed. Experimental results show that the proposed segmentation based depth coding method outperforms H.264/AVC and H.264/MVC by more than 2 dB at similar bitrates. (C) 2011 Elsevier Inc. All rights reserved.

关键词： Depth map Virtual view Multiview video coding 3DTV Segmentation-based video coding Region-merging Color-depth segmentation texture coding

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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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Palmprint verification using binary contrast context vector

Palmprint verification using binary contrast context vector

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1st Asian Conference on Pattern Recognition (ACPR)

作者： Feng, Yi Huang, Lei Liu, Changping Chinese Acad Sci Inst Automat Natl Lab Pattern Recognit Beijing Peoples R China

ISBN: (纸本)9781457701214;9781457701221

Palmprint recognition has attracted much attention in recent years. Many algorithms based texture coding achieve high accuracy. However they are still sensitive to local unsteady region introduced by variations of hand pose and other conditions. In this paper we proposed a novel feature extraction algorithm, namely binary contrast context vector (BCCV), to represent multiple contrast distribution for a local region. Due to forming the local contrast value into a binary vector, contrast context could be used to match more effectively. Furthermore, by using BCCV we apply an adaptive threshold to mask the stable local region before matching. Our experiment results on public palmprint database shows that the proposed BCCV achieves lower equal error rate (EER) than other two state-of-the-art approaches.

关键词： palmprint recognition contrast context binary vector texture coding

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A novel scalable texture video coding scheme with GPCA

A novel scalable texture video coding scheme with GPCA

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32nd IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Liu, Jian Zhuang, Yueting Yao, Lei Wu, Fei Zhejiang Univ Coll Comp Sci Hangzhou 310027 Peoples R China

ISBN: (纸本)9781424407286

This paper proposes a novel SNR scalable coding method with the support of generalized principle component analysis (GPCA). This method encodes the low-pass and high-pass pictures generated by the MCTF decomposition with a hybrid linear model instead of traditional block-based DCT transform. GPCA is a powerful tool to identify the hybrid linear model in the textures, which segment the texture into heterogeneous regions, and then encode each region with PCA method. By keeping various proportions of PCA coefficients, and altering the quantization step sizes for different layers, a better scalable coding result can be achieved.

关键词： video coding scalability texture coding GPCA hybrid linear model

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An MPEG-4 texture coding approach using refined boundary block merging and adaptive SA-DCT

An MPEG-4 texture coding approach using refined boundary blo...

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International Multiconference of Engineers and Computer Scientists

作者： Shih, Jau-Ling Lee, Chang-Hsing Chiang, Yen-Yi Chung Hua Univ Dept Comp Sci & Informat Engn 707Sec 2WuFu Rd Hsinchu Taiwan

ISBN: (纸本)9889867133

The refined boundary block merging (RBBM) algorithm is proposed for coding the texture information of arbitrarily shaped video objects in MPEG-4. In RBBM, only horizontal and vertical merging are taken into account since the diagonal merging ratio is very small. To further improve the coding performance, adaptive SA-DCT is then exploited to efficiently encode each merged block. Experimental results confirm the effectiveness of the proposed algorithm.

关键词： MPEG4 texture coding SA-DCT

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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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A multi-layered image coding using multiple transforms

A multi-layered image coding using multiple transforms

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7th International Conference on Machine Learning and Cybernetics

作者： Liu, Li-Xiong Wang, Yuan-Quan Wang, Wei-Wei Beijing Inst Technol Sch Comp Sci & Technol Beijing 100081 Peoples R China China Univ Geosci Fac Informat & Engn Wuhan 430074 Peoples R China Tianjin Univ Technol Sch Comp Sci & Technol Tianjin 300191 Peoples R China

ISBN: (纸本)9781424420957

This paper proposes a new multi-layered image coding algorithm based on wavelet and matching pursuit transforms. The original image is divided into smooth and edge layer and texture layer, Different compression algorithms of coding are adopted to each different layer in order to achieve optimization for the entire image. Case studies have demonstrated that this coding method can capture texture and edge characteristics efficiently. Besides, the quality of reconstructed image is better than traditional single wavelet image coding algorithm at low bit rates.

关键词： wavelet multi-layer image image coding matching pursuit texture coding

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texture matching method for lossless image coding

Texture matching method for lossless image coding

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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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