| Title | 3D Space Representation Using Epipolar Plane Depth Image |
| Author | Takashi Ishibashi, Tomohiro Yendo, Mehrdad Panahpour Tehrani (Graduate School of Engineering, Nagoya University, Japan), Toshiaki Fujii (Graduate School of Science and Engineering, Tokyo Institute of Technology, Japan), Masayuki Tanimoto (Graduate School of Engineering, Nagoya University, Japan) |
| Page | pp. 22 - 25 |
| Keyword | FTV, EPI, EPDI, Ray-Space, GDM |
| Abstract | We propose a novel 3D space representation for multi-view
video, using epipolar plane depth images (EPDI). Multi-view
video plus depth (MVD) is used as common data format for
FTV(Free-viewpoint TV), which enables synthesizing virtual
view images. Due to large amount of data and complexity of
the multi-view video coding (MVC), compression of MVD is
a challenging issue. We address this problem and propose a
new representation that is constructed from MVD using rayspace.
MVD is converted into image and depth ray-spaces.
The proposed representation is obtained by converting each
of ray-spaces into a global depth map and a texture map using
EPDI. Experiments demonstrates the analysis of this representation,
and its efficiency. |
| Title | View Synthesis Error Analysis for Selecting the Optimal QP of Depth Map Coding in 3D Video Application |
| Author | Yanwei Liu, Song Ci, Hui Tang (Institute of Acoustics, Chinese Academy of Sciences, China) |
| Page | pp. 26 - 29 |
| Keyword | view synthesis error analysis, depth map coding, selecing QP |
| Abstract | In 3D video communication, how to select the appropriate quantization parameter (QP) for depth map coding is very important for obtaining the optimal view synthesis quality. This paper first analyzes the depth uncertainty induced two kinds of view synthesis errors, namely the original depth error induced view synthesis error and the depth compression induced view synthesis error, and then proposes a quadratic model to characterize the relationship between the view synthesis quality and the depth quantization step size. The proposed model can find the inflexion point in the curve of the view synthesis quality with the increasing depth quantization step size. Experimental results show that, given the rate constraint for depth map, the proposed model can accurately find the optimal QP for depth map coding. |
| Title | Suppressing Texture-Depth Misalignment for Boundary Noise Removal in View Synthesis |
| Author | Yin Zhao (Zhejiang University, China), Zhenzhong Chen (Nanyang Technological University, Singapore), Dong Tian (Mitsubishi Electric Research Labs, U.S.A.), Ce Zhu (Nanyang Technological University, Singapore), Lu Yu (Zhejiang University, China) |
| Page | pp. 30 - 33 |
| Keyword | 3D video, boundary noise, DIBR, texture-depth misalignment, view synthesis |
| Abstract | During view synthesis based on depth maps, also known as Depth-Image-Based Rendering (DIBR), annoying artifacts are often generated around foreground objects, yielding the visual effects that slim silhouettes of foreground objects are scattered into the background. The artifacts are referred as the boundary noises. We investigate the cause of boundary noises, and find out that they result from the misalignment between texture and depth information along object boundaries. Accordingly, we propose a novel solution to remove such boundary noises by applying restrictions during forward warping on the pixels within the texture-depth misalignment regions. Experiments show this algorithm can effectively eliminate most boundary noises and it is also robust for view synthesis with compressed depth and texture information. |
| Title | A High Efficiency Coding Framework for Multiple Image Compression of Circular Camera Array |
| Author | Dongming Xue (Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Japan), Akira Kubota (Faculty of Science and Engineering, Chuo University, Japan), Yoshinori Hatori (Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Japan) |
| Page | pp. 34 - 37 |
| Keyword | multi-view video coding, virtual plane, polar axis, poxel framework |
| Abstract | Many existing multi-view video coding techniques remove inter-viewpoint redundancy by applying disparity compensation in conventional video coding frameworks, e.g., H264/MPEG4. However, conventional methodology works ineffectively as it ignores the special features of the inter-view-point disparity. This paper proposed a framework using virtual plane for multi-view image compression, such as we can largely reduce the disparity compensation cost. Based on this VP predictor, we design a poxel (probabilistic voxelized volume) framework, which can integrate the information of the cameras in different view-points in the polar axis to obtain a more effective compression performance. In addition, considering the replay convenience of the multi-view video at the receiving side, we reformed overhead information in polar axis at the sending side in advance. |
| Title | Exploiting Depth Information for Fast Multi-View Video Coding |
| Author | Brian W. Micallef, Carl J. Debono, Reuben A. Farrugia (University of Malta, Malta) |
| Page | pp. 38 - 41 |
| Keyword | 3DTV, disparity vector estimation, geometric disparity vector predictor, multi-view video coding |
| Abstract | Multi-view video coding exploits inter-view redundancies to compress the video streams and their associated depth information. These techniques utilize disparity estimation techniques to obtain disparity vectors (DVs) across different views. However, these methods contribute to the majority of the computational power needed for multi-view video encoding. This paper proposes a solution for fast disparity estimation based on multi-view geometry and depth information. A DV predictor is first calculated followed by an iterative or a fast search estimation process which finds the optimal DV in the search area dictated by the predictor. Simulation results demonstrate that this predictor is reliable enough to determine the area of the optimal DVs to allow a smaller search range. Furthermore, results show that the proposed approach achieves a speedup of 2.5 while still preserving the original rate-distortion performance. |
| Title | An Adaptive Early Skip Mode Decision Scheme for Multiview Video Coding |
| Author | Bruno Zatt (Federal University of Rio Grande do Sul, Brazil), Muhammad Shafique (Karlsruhe Institute of Technology, Germany), Sergio Bampi (Federal University of Rio Grande do Sul, Brazil), Jörg Henkel (Karlsruhe Institute of Technology, Germany) |
| Page | pp. 42 - 45 |
| Keyword | MVC, Early Skip, Video Coding, Mode Decision |
| Abstract | In this work a novel scheme is proposed for adaptive early SKIP mode decision in the multiview video coding based on mode correlation in the 3D-neighborhood, variance, and rate-distortion properties. Our scheme employs an adaptive thresholding mechanism in order to react to the changing values of Quantization Parameter (QP). Experimental results demonstrate that our scheme provides a consistent time saving over a wide range of QP values. Compared to the exhaustive mode decision, our scheme provides a significant reduction in the encoding complexity (up to 77%) at the cost of a small PSNR loss (0.172 dB in average). Compared to state-of-the-art, our scheme provides an average 2x higher complexity reduction with a relatively higher PSNR value (avg. 0.2 dB). |
| Title | Electoronic Hologram Generation Using High Quality Color and Depth Information of Natural Scene |
| Author | Kousuke Nomura (Tokyo University of Science, Japan), Ryutaro Oi, Taiichiro Kurita (National Institute of Information and Communications Technology, Japan), Takayuki Hamamoto (Tokyo University of Science, Japan) |
| Page | pp. 46 - 49 |
| Keyword | CGH, color hologram, real Scene, natural light, optically reconstruction |
| Abstract | Recently, the computer generated hologram (CGH) methods are heavily researched. In those conventional CGH, however, it is not so common to provide a hologram of real scene. This time we report that we could get the properly reconstruction of image by using our proposal method against the color hologram anew. We confirmed that our proposed color hologram properly recorded both color and the 3-D information of the space by an assessment experiment which optically reconstructs the hologram. |
| Title | Complementary Coding Mode Design Based on R-D Cost Minimization for Extending H.264 Coding Technology |
| Author | Tomonobu Yoshino, Sei Naito, Shigeyuki Sakazawa, Shuichi Matsumoto (KDDI R&D Laboratories, Japan) |
| Page | pp. 50 - 53 |
| Keyword | low bit-rate video coding, high resolution video coding, H.264, SKIP mode |
| Abstract | To improve high resolution video coding efficiency under low bit-rate condition, an appropriate coding mode is required from an R-D optimization (RDO) perspective, although a coding mode defined within the H.264 standard is not always optimal for RDO criteria. With this in mind, we previously proposed extended SKIP modes with close-to-optimal R-D characteristics. However, the additional modes did not always satisfy the optimal R-D characteristics, especially for low bit-rate coding. In response, in this paper, we propose an enhanced coding mode capable of providing a candidate corresponding to the minimum R-D cost by controlling the residual signal associated with the extended SKIP mode. The experimental result showed that the PSNR improvement against H.264 and our previous approach reached 0.42 dB and 0.24 dB in the maximum case, respectively. |
| Title | Enhanced Video Compression with Region-Based Texture Models |
| Author | Fan Zhang, David Bull (University of Bristol, U.K.) |
| Page | pp. 54 - 57 |
| Keyword | video, compression, texture, warping, synthesis |
| Abstract | This paper presents a region-based video compression algorithm based on texture warping and synthesis. Instead of encoding whole images or prediction residuals after translational motion estimation, this algorithm employs a perspective motion model to warp static textures and uses a texture synthesis approach to synthesise dynamic textures. Spatial and temporal artefacts are prevented by an in-loop video quality assessment module. The proposed method has been integrated into an H.264 video coding framework. The results show significant bitrate savings, up to 55%, compared with H.264, for similar visual quality. |
| Title | Coding Efficient Improvement by Adaptive Search Center Definition |
| Author | Kyohei Oba, Takahiro Bandou, Tian Song, Takashi Shimamoto (Tokushima University, Japan) |
| Page | pp. 58 - 61 |
| Keyword | H.264/AVC, Motion Estimation, Inter Prediction, RDO |
| Abstract | In this paper, an efficient search center definition algorithm is
proposed for H.264/AVC. H.264/AVC achieved high coding efficiency by introducing some new coding tools including a new definition of the search center. However, the definition of the search center is not efficient in the case of significant motions. This work proposes some new search center candidates using spatial and temporal correlations of motion vectors to improve the coding efficiency. Simulation results show that the proposed search centers can achieve very much bit saving but induced high computation complexity. Additional complexity reduction algorithm is also introduced to improve the trade off between bit saving and implementation performance. This work realized a maximum bit saving of 19%. |
| Title | A Novel Coding Scheme for Intra Pictures of H.264/AVC |
| Author | Jin Young Lee, Jaejoon Lee, Hochen Wey, Du-Sik Park (Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Republic of Korea) |
| Page | pp. 62 - 65 |
| Keyword | H.264/AVC, intra coding, intra prediction |
| Abstract | A novel intra coding scheme is proposed to improve coding performance in intra pictures of H.264/AVC. The proposed method generates two sub-images, which are defined as a sampled image and a prediction error image in this paper, from an original image, and then encodes them separately. Especially, in an intra prediction process of encoding, the sampled image employs the original intra prediction modes, while the prediction error image uses newly defined four intra prediction modes. Experimental results demonstrate that the proposed method achieves significantly higher intra coding performance and reduces encoding complexity with the smaller number of a rate-distortion (RD) cost calculation process, as compared with the original intra coding method of H.264/AVC. |
| Title | Entropy Coding in Video Compression Using Probability Interval Partitioning |
| Author | Detlev Marpe, Heiko Schwarz (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Germany), Thomas Wiegand (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute/Technical University of Berlin, Germany) |
| Page | pp. 66 - 69 |
| Keyword | entropy coding, variable length coding |
| Abstract | We present a novel approach to entropy coding, which provides the
coding efficiency and simple probability modeling capability of
arithmetic coding at the complexity level of Huffman coding.
The key element of the proposed approach is a partitioning of
the unit interval into a small set of probability intervals.
An input sequence of discrete source symbols is mapped to
a sequence of binary symbols and each of the binary symbols is
assigned to one of the probability intervals.
The binary symbols that are assigned to a particular probability
interval are coded at a fixed probability using a simple code
that maps a variable number of binary symbols to variable length
codewords.
The probability modeling is decoupled from the actual
binary entropy coding.
The coding efficiency of the probability interval partitioning
entropy (PIPE) coding is comparable to
that of arithmetic coding. |
| Title | Separable Wiener Filter Based Adaptive In-Loop Filter for Video Coding |
| Author | Mischa Siekmann, Sebastian Bosse, Heiko Schwarz, Thomas Wiegand (Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Germany) |
| Page | pp. 70 - 73 |
| Keyword | Video Compression, In-loop Filtering, Wiener Filter, Separable Image Filtering, Regional Filtering |
| Abstract | Recent investigations have shown that a non-separable Wiener
filter, that is applied inside the motion-compensation loop,
can improve the coding efficiency of hybrid video coding
designs. In this paper, we study the application of separable Wiener filters. Our design includes the possibility to
adaptively choose between the application of the vertical,
horizontal, or combined filter. The simulation results verify
that a separable in-loop Wiener filter is capable of providing
virtually the same increase in coding efficiency as a non-
separable Wiener filter, but at a significantly reduced decoder
complexity. |
| Title | Hyperspectral Image Compression Suitable for Spectral Analysis Application |
| Author | Kazuma Shinoda, Yukio Kosugi, Yuri Murakami, Masahiro Yamaguchi, Nagaaki Ohyama (Tokyo Institute of Technology, Japan) |
| Page | pp. 74 - 77 |
| Keyword | Hyperspectral image, Image compression, Vegetation index, JPEG2000 |
| Abstract | This paper presents a HSI compression considering the error of both vegetation index and spectral data. The proposed method separates a hyperspectral data into spectral data for vegetation index and residual data. Both of the data are encoded by using a seamless coding individually. By holding the spectral channels required for vegetation index in the head of the code-stream, a precise vegetation analysis can be done in a low bit rate. Additionally, by decoding the residual data, the spectral data can be reconstructed in low distortion. |
| Title | A Background Model Based Method for Transcoding Surveillance Videos Captured by Stationary Camera |
| Author | Xianguo Zhang (Peking University, China), Luhong Liang, Qian Huang (Institute of Computing Technology, Chinese Academy of Sciences, China), Tiejun Huang, Wen Gao (Peking University, China) |
| Page | pp. 78 - 81 |
| Keyword | surveillance, archive, transcode, background model, difference frame |
| Abstract | Real-world video surveillance applications require storing videos without neglecting any part of scenarios for weeks or months. To reduce the storage cost, the high bit-rate videos from cameras should be transcoded into a more efficient compressed format with little quality loss. We propose a background model based method to improve the transcoding efficiency for surveillance videos captured by stationary cameras, and objectively measure it. Experimental Results show this method saves about half the used bits compared with the full-decoding-full-encoding method. |
| Title | Analysis of In-Loop Denoising in Lossy Transform Coding |
| Author | Eugen Wige, Gilbert Yammine (Multimedia Communications and Signal Processing / University of Erlangen-Nuremberg, Germany), Peter Amon, Andreas Hutter (Siemens Corporate Technology / Information and Automation Technologies, Germany), Andre Kaup (Multimedia Communications and Signal Processing / University of Erlangen-Nuremberg, Germany) |
| Page | pp. 82 - 85 |
| Keyword | high quality compression, predictor denoising, quantization effects |
| Abstract | When compressing noisy image sequences, the compression efficiency
is limited by the noise amount within these image sequences
as the noise part cannot be predicted. In this paper, we investigate
the influence of noise within the reference frame on lossy video coding of noisy image sequences. We estimate how much noise is
left within a lossy coded reference frame. Therefore we analyze the
transform and quantization step inside a hybrid video coder, specifically H.264/AVC. The noise power after transform, quantization,
and inverse transform is calculated analytically. We use knowledge
of the noise power within the reference frame in order to improve the
inter frame prediction. For noise filtering of the reference frame, we
implemented a simple denoising algorithm inside the H.264/AVC
reference software JM15.1. We show that the bitrate can be decreased
by up to 8.1% compared to the H.264/AVC standard for high
resolution noisy image sequences. |
| Title | An Efficient Side Information Generation Using Seed Blocks for Distributed Video Coding |
| Author | DongYoon Kim, DongSan Jun, HyunWook Park (KAIST, Republic of Korea) |
| Page | pp. 86 - 89 |
| Keyword | Distrivuted vidoe coding, Wyner-Ziv video coding, Side information |
| Abstract | Recently, a new video coding technique, distributed video coding (DVC), is an emerging research area for low power video coding applications. In the DVC, the encoder is much simpler than the conventional video codec, whereas the decoder is very heavy. The DVC decoder exploits side information which is generated by motion compensated frame interpolation to reconstruct the Wyner-Ziv frame. This paper proposes an efficient side information generation algorithm using seed blocks for DVC. Seed blocks are firstly selected to be used for motion estimation of the other blocks. As the side information is close to the target image, the final reconstructed image in the DVC decoder has better quality and the compression ratio becomes high. The proposed method contributes to improve the DVC compression performance with reduced computing time. Experimental results show that accurate motion vectors are estimated by the proposed method and its computational complexity of motion estimation is significantly reduced in comparison with the previous methods. |
| Title | Compressive Video Sensing Based on User Attention Model |
| Author | Jie Xu (Advanced Computing Research Laboratory, Institute of Computing Technology, Chinese Academy of Sciences, China), Jianwei Ma (School of computational Science, Florida State University, U.S.A.), Dongming Zhang, Yongdong Zhang, Shouxun Lin (Advanced Computing Research Laboratory, Institute of Computing Technology, Chinese Academy of Sciences, China) |
| Page | pp. 90 - 93 |
| Keyword | compressive sensing, video, user attention model, ROI |
| Abstract | We propose a compressive video sensing scheme based on user attention model (UAM) for real video sequences acquisition. In this work, for every group of consecutive video frames, we set the first frame as reference frame and build a UAM with visual rhythm analysis (VRA) to automatically determine region-of-interest (ROI) for non-reference frames. The determined ROI usually has significant movement and attracts more attention. Each frame of the video sequence is divided into non-overlapping blocks of 16x16 pixel size. Compressive video sampling is conducted in a block-by-block manner on each frame through a single operator and in a whole region manner on the ROIs through a different operator. Our video reconstruction algorithm involves alternating direction l1-norm minimization algorithm (ADM) for the frame difference of non-ROI blocks and minimum total-variance (TV) method for the ROIs. Experimental results showed that our method could significantly enhance the quality of reconstructed video and reduce the errors accumulated during the reconstruction. |
| Title | Advanced Inpainting-Based Macroblock Prediction with Regularized Structure Propagation in Video Compression |
| Author | Yang Xu, Hongkai Xiong (Shanghai Jiao Tong University, China) |
| Page | pp. 94 - 97 |
| Keyword | belief propagation, tensor voting, inpainting, model selection, H.264 |
| Abstract | In this paper, we propose an optimized inpainting-based macroblock (MB) prediction mode (IP- mode) in the state-of-the-art H.264/AVC video compression engine, and investigate a natural extension of structured sparsity over the ordered Belief Propagation (BP) inference in inpainting-based prediction. The IP- mode is regularized by a global spatio-temporal consistency between the predicted content and the co-located known texture, and could be adopted in both Intra and Inter frames without redundant assistant information. It is solved by an optimization problem under Markov Random Field (MRF), and the structured sparsity of the predicted macroblock region is inferred by tensor voting projected from the decoded regions to tune the priority of message scheduling in BP with a more convergent manner. Rate-distortion optimization is maintained to select the optimal mode among the inpainting-based prediction (IP-), the intra-, and inter- modes. Compared to the existing prediction modes in H.264/AVC, the proposed inpainting-based prediction scheme is validated to achieve a better R-D performance for homogeneous visual patterns and behave a more robust error resilience capability with an intrinsic probabilistic inference. |
| Title | An Improved Iterative Algorithm for Calculating the Rate-Distortion Performance of Causal Video Coding for Continuous Sources and its Application to Real Video Data |
| Author | En-hui Yang, Chang Sun, Lin Zheng (University of Waterloo, Canada) |
| Page | pp. 98 - 101 |
| Keyword | video coding, causal video coding, rate-distortion performance, soft decision quantization, interactive algorithm |
| Abstract | An improved iterative algorithm is first proposed to calculate the rate-distortion performance of causal video coding for any continuous sources. Instead of using continuous reproduction alphabets, it utilizes finite reproduction alphabets and iteratively updates them along with transitional probabilities from the continuous source to reproduction letters, thus overcoming the computation complexity problem encountered when applying the algorithm recently proposed by Yang et al for discrete sources to continuous sources. The proposed algorithm converges in the sense that the rate-distortion cost is monotonically decreasing until a stationary point is reached. It is then applied to practical video data to establish some theoretic coding performance benchmark. In comparison with H.264, experiments show that under the same motion compensation setting, causal video coding offers a roughly 1 dB coding gain on average over H.264 for the IPPIPP…GOP structure. This suggests that an area one could explore to further improve the rate-distortion performance of H.264 be how quantization and coding should be performed conditionally given previous frames and coded frames and given motion compensation. |
| Title | Technical Design & IPR Analysis for Royalty-Free Video Codecs |
| Author | Cliff Reader (none, U.S.A.) |
| Page | pp. 102 - 105 |
| Keyword | Royalty-free, video codec, performance, complexity, IPR |
| Abstract | Royalty-free standards for image and video coding have been actively discussed for over 20 years. This paper breaks down the issues of designing royalty-free codecs into the major topics of requirements, video coding tools, classes of patents and performance. By dissecting the codec using a hierarchy of major to minor coding tools, it is possible to pinpoint where a patent impacts the video coding, and what the consequence will be of avoiding the patented tool. |
| Title | Accelerating Pixel Predictor Evolution Using Edge-Based Class Separation |
| Author | Seishi Takamura, Masaaki Matsumura, Hirohisa Jozawa (NTT Cyber Space Laboratories, NTT Corporation, Japan) |
| Page | pp. 106 - 109 |
| Keyword | Genetic programming, lossless image coding, pixel prediction, divide and conquer |
| Abstract | Evolutionary methods based on genetic programming (GP) enable dynamic algorithm generation, and have been successfully applied to many areas such as plant control, robot control, and stock market prediction. However, one of the challenges of this approach is its high computational complexity. Conventional image/video coding methods such as JPEG and H.264 all use fixed (non-dynamic) algorithms without exception. However, one of the challenges of this approach is its high computational complexity. In this article, we introduce a GP-based image predictor that is specifically evolved for each input image, as well as local image properties such as edge direction. Via the simulation, proposed method demonstrated ~180 times faster evolution speed and 0.02-0.1 bit/pel lower bit rate than previous method. |
| Title | Avoidance of Singular Point in Reversible KLT |
| Author | Masahiro Iwahashi (Nagaoka University of Technology, Japan), Hitoshi Kiya (Tokyo Metropolitan University, Japan) |
| Page | pp. 110 - 113 |
| Keyword | KLT, error, reversible, coding |
| Abstract | Permutation of order and sign of signals are introduced to avoid the singular point problem of a reversible transform. Even though a transform in the lifting structure can be "reversible" in spite of rounding operations, its multiplier coefficients have singular points (SP). Around the SP, rounding errors are magnified to huge amount and the coding efficiency is decreased. We investigate effect of the permutations on rotation angles and confirmed that PSNR was improved by 14 [dB] for RGB color components. |
| Title | Super-Resolution Decoding of JPEG-Compressed Image Data with the Shrinkage in the Redundant DCT Domain |
| Author | Takashi Komatsu, Yasutaka Ueda, Takahiro Saito (Kanagawa University, Japan) |
| Page | pp. 114 - 117 |
| Keyword | JPEG, decoding, redundant DCT, shrinkage, super-resolution |
| Abstract | Alter, Durand and Froment introduced the total-variation (TV) minimization approach to the artifact-free JPEG decoding. They formulated the decoding problem as the constrained TV restoration problem, in which the TV semi-norm of its restored color image is minimized under the constraint that each DCT coefficient of the restored color image should be in the quantization interval of its corresponding DCT coefficient of the JPEG-compressed data. This paper proposes a new restoration approach to the JPEG decoding. Instead of the TV regularization, our new JPEG-decoding method employs a shrinkage operation in the redundant DCT domain, to mitigate degradations caused by the JPEG coding. |
| Title | Image Interpolation via Regularized Local Linear Regression |
| Author | Xianming Liu, Debin Zhao (Harbin Institute of Technology, China), Ruiqin Xiong, Siwei Ma, Wen Gao (Peking University, China) |
| Page | pp. 118 - 121 |
| Keyword | Image interpolation, regularized local linear regression, edge preservation |
| Abstract | In this paper, we present an efficient image interpolation scheme by using regularized local linear regression (RLLR). On one hand, we introduce a robust estimator of local image structure based on moving least squares, which can efficiently handle the statistical outliers compared with ordinary least squares based methods. On the other hand, motivated by recent progress on manifold based semi-supervise learning, the intrinsic manifold structure is explicitly considered by making use of both measured and unmeasured data points. In particular, the geometric structure of the marginal probability distribution induced by unmeasured samples is incorporated as an additional locality preserving constraint. The optimal model parameters can be obtained with a closed-form solution by solving a convex optimization problem. Experimental results demonstrate that our method outperform the existing methods in both objective and subjective visual quality over a wide range of test images. |
| Title | Fast and Efficient Gaussian Noise Image Restoration Algorithm by Spatially Adaptive Filtering |
| Author | Tuan Anh Nguyen, Myoung Jin Kim, Min Cheol Hong (Soongsil University, Republic of Korea) |
| Page | pp. 122 - 125 |
| Keyword | noise, detection, removal, constraint, smoothness |
| Abstract | In this paper, we propose a spatially adaptive noise removal algorithm using local statistics that consists of two stages: noise detection and removal. To corporate desirable properties into denoising process, the local weighted mean, local weighted activity, and local maximum are defined. With these local statistics, the noise detection function is defined and a modified Gaussian filter is used to suppress the detected noise components. The experimental results demonstrate the effectiveness of the proposed algorithm. |
| Title | Theoretical Analysis of Trend Vanishing Moments for Directional Orthogonal Transforms |
| Author | Shogo Muramatsu, Dandan Han, Tomoya Kobayashi, Hisakazu Kikuchi (Niigata University, Japan) |
| Page | pp. 130 - 133 |
| Keyword | M-D filter banks, M-D Wavelets, Directional transforms, Nonseparable filter design, Image coding |
| Abstract | This work contributes to investigate theoretical properties of the
trend vanishing moments (TVMs) which the authors have defined in a
previous work and applied to the directional design of 2-D
nonseparable GenLOT. Some significant properties of TVMs are shown
theoretically and experimentally. |
| Title | A Study on Memorability and Shoulder-Surfing Robustness of Graphical Password Using DWT-Based Image Blending |
| Author | Takao Miyachi, Keita Takahashi, Madoka Hasegawa, Yuichi Tanaka, Shigeo Kato (Utsunomiya University, Japan) |
| Page | pp. 134 - 137 |
| Keyword | Graphical password, discrete wavelet transform, authentication, usable security |
| Abstract | We propose a graphical password method which is difficult to steal original pass-image by using characteristics of human vision system. In our method, we combine low frequency components of a decoy picture with high frequency components of a pass-image. It is easy for legitimate users to recognize the pass-image in the blended image. On the other hand, this task is difficult for attackers.
We used discrete wavelet transform (DWT) to blend a decoy image and a pass-image. User studies are conducted to evaluate memorability and shoulder-surfing robustness of this method. |
| Title | Scalable Image Scrambling Method Using Unified Constructive Permutation Function on Diagonal Blocks |
| Author | KokSheik Wong (University of Malaya, Malaysia), Kiyoshi Tanaka (Shinshu University, Japan) |
| Page | pp. 138 - 141 |
| Keyword | scalable scrambling, UCPF, diagonal block, image encryption |
| Abstract | In this paper, an extension of ScaScra [1] is proposed to scalably scramble an image in the diagonal direction for achieving distorted scanline-like effect. The non-overlapping diagonal blocks are first defined and the unified constructive permutation function is applied to scramble pixels in each diagonal block. Scalability in scrambling is achieved by varying the block size. Experiments were carried out to objectively and subjectively verify the basic performance of the proposed extension and compare them to the results of ScaScra by using standard test images. Evaluations on pixel correlation and entropy are also carried out to verify the performance of both ScaScra and the proposed extension. |
| Title | Memory-Efficient Parallelization of JPEG-LS with Relaxed Context Update |
| Author | Simeon Wahl, Zhe Wang, Chensheng Qiu, Marek Wroblewski, Lars Rockstroh, Sven Simon (University of Stuttgart, Germany) |
| Page | pp. 142 - 145 |
| Keyword | JPEG-LS, Lossless Image Coding, Parallelization, Context Update |
| Abstract | A relaxation to the context update of JPEG-LS by delaying the update procedure is proposed, in order to achieve a guaranteed degree of parallelism with a negligible effect on the compression ratio. The lossless mode of JPEG-LS including the run-mode is considered. A descewing scheme is provided generating a bit-stream that preserves the order needed for the decoder to mimic the prediction in a consistent way. |
| Title | H.264 Hierarchical P Coding in the Context of Ultra-Low Delay, Low Complexity Applications |
| Author | Danny Hong, Michael Horowitz, Alexandros Eleftheriadis, Thomas Wiegand (Vidyo, Inc., U.S.A.) |
| Page | pp. 146 - 149 |
| Keyword | H.264, hierarchical P coding |
| Abstract | Despite the attention that hierarchical B picture coding has received, little attention has been given to a related technique called hierarchical P picture coding. P picture only coding without reverse prediction is necessary in constrained bit rate applications that require ultra-low delay and/or low complexity, such as videoconferencing. Such systems, however, have been using the traditional IPPP picture coding structure almost exclusively. In this paper, we investigate the use of hierarchical P coding vs. traditional IPPP coding and demonstrate that it has significant advantages which have not yet been well documented or understood. From a pure coding efficiency point of view, we show that for encoders configured to use ultra-low delay and low complexity coding tools, hierarchical P coding achieves an average advantage of 7.86% BD-rate and 0.34 dB BD-SNR. |
| Title | Correlation Modeling with Decoder-Side Quantization Distortion Estimation for Distributed Video Coding |
| Author | Jozef Skorupa, Jan De Cock, Jürgen Slowack, Stefaan Mys (Ghent University -- IBBT, Belgium), Nikos Deligiannis (Vrije Universiteit Brussel -- IBBT, Belgium), Peter Lambert (Ghent University -- IBBT, Belgium), Adrian Munteanu (Vrije Universiteit Brussel -- IBBT, Belgium), Rik Van de Walle (Ghent University -- IBBT, Belgium) |
| Page | pp. 150 - 153 |
| Keyword | distributed video coding, correlation modeling, quantization distortion |
| Abstract | Aiming for low-complexity encoding, distributed video coders still fail to achieve the performance of current industrial standards for video coding. One of most important problems in this area is the accurate modeling of the correlation between the predicted signal and the original video. In our previous work we showed that exploiting the quantization distortion can significantly improve the accuracy of a correlation estimator. In this paper we describe how the quantization distortion can be exploited purely at the decoder side without any performance penalty when compared to an encoder-aided system. As a result, the proposed correlation estimator delivers state-of-the-art modeling accuracy while neatly fitting the low-encoder-complexity characteristic of distributed video coding. |
| Title | Content-Based Retrieval by Multiple Image Examples for Sign Board Retrieval |
| Author | Atsuo Yoshitaka (JAIST, Japan), Terumasa Hyoudou (Hiroshima University, Japan) |
| Page | pp. 154 - 157 |
| Keyword | Multiple image examples, QBE, image retrieval |
| Abstract | In the area of retrieving image databases, one of the promising approaches is to retrieve it by specifying image example. However, specifying a single image example is not always sufficient to get satisfactory result, since one image example does not give comprehensive ranges of values that reflect the various aspects of the object to be retrieved.
In this paper, we propose a method of retrieving images by specifying multiple image examples that is designed for retrieving sign boards. Features of color, shape, and spatial relation of color regions are extracted from example images, and they are clustered so as to obtain proper range of values.
Compared with QBE systems that accept only a single image as the query condition, MIERS (Multi-Image Example-based Retrieval System) returns better retrieval result, where the experimental result showed that specifying more examples helps to improve recall with little deterioration of precision. |