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conferenceon visual communications and image processing 2006

作者： Kim, YS Jung, YJ Thang, TC Ro, YM Information and Communications Univ. (South Korea)

ISBN: (纸本)0819461172

In scalable video coding (SVC), video quality can be controlled by bit-stream extraction. The bit-stream extraction is to extract network abstraction layer (NAL) units for the required quality. Since scalable bit-stream is packed in NAL units, quality control of SVC video is highly related to NAL unit extraction policy at a given bit-rate. Therefore, effective extraction policy is required to provide SVC video with optimal quality. In this paper, a SVC bit-stream extraction method based on perceptual quality is proposed. The main goal of this work is to find the optimal extraction policy for SVC bit-stream that contain the spatial, temporal, and SNR scalability at a given bit-rate. Also, to consider perceptual quality relied on video characteristics, the video segments are classified into different classes, namely action, crowd, dialog, scenery, and text&graphic. As a result of a subjective test on the classified video scenes, consistent characteristic of perceptual quality preference is achieved. Based on this, quality information table (QIT) has been determined for each class which guides the bit-stream extraction process. The determined QIT is applied to SVC bit-stream extraction depending on to which class a video segment belongs. In the experiment, the proposed extraction scheme is applied for SVC bit-stream extraction belongs to action class. Extraction policy to maximize perceptual quality of action class is applied based on QIT for action class. The extracted video and multi-dimensional scalability resulted from the proposed scheme are also described.

关键词： SVC bit-stream extraction perceptual quality quality information table

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Video compression with flexible playback order based on distributed source coding

Video compression with flexible playback order based on dist...

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conferenceon visual communications and image processing 2006

作者： Cheung, NM Wang, HS Ortega, A Univ So Calif Dept Elect Engn Signal & Image Proc Inst Los Angeles CA 90089 USA

ISBN: (纸本)0819461172

Some emerging applications may require flexible playback features for time-based media, such as video, that cannot be directly supported by current compression standards, because for these decoding of frames can only be done in a predetermined order. An example would be a video application where both backward and forward frame-by-frame playback are to be supported. A standard codec could support this by decoding complete GOPs in the desired order, and then playing back one frame at a time. Thus, potentially significant added delay and memory are needed to support backward playback, which can be lowered if small GOP sizes are chosen, at the cost of reduced coding efficiency. Other example applications where flexible playback may be desirable include switching between different views in multiview video coding, and accessing individual spectral bands in hyperspectral imagery. In this work we address flexible playback by showing that it becomes feasible when a particular data unit (e.g., a video frame) can be decoded using information from either one of a number of other data units (e. in the video case the next frame or the previous frame). Note that this is different from structures such as bi-directionally predicted frames, which require both predictor frames to be available at the decoder. We cast this problem as one of source coding with uncertainty about decoder side-information and propose a solution based on distributed source coding. In addition, we propose macroblock-based mode switching algorithms in the context of distributed video coding to improve coding efficiency. Our results show that, using forward/backward playback as an example, our proposed solution can achieve good coding efficiency without incurring additional delay and memory overhead.

关键词： flexible playback distributed source coding distributed video coding macroblock-based mode switching

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Quality enhancement of printed-and-scanned images using distributed coding

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SIGNAL processing 2007年第6期87卷 1301-1313页

作者： Voloshynovskiy, S. Koval, O. Deguillaume, F. Pun, T. Univ Geneva CUI CH-1211 Geneva 4 Switzerland

In this paper we address visual communications via print-and-scan channels from an information-theoretic point of view as communications with side information that targets quality enhancement of visual data at the output of this type of channels. The solution to this problem addresses important aspects of multimedia data processing and management. A practical approach to side information communications for printed documents based on Wyner-Ziv and Gray setups is analyzed in the paper that assumes two separated communications channels where an appropriate distributed coding should be elaborated. The printing channel is considered to be a direct visual channel for images ("analog" channel with degradations). The "digital channel" is considered to be an appropriate auxiliary channel exploited to communicate the information exploited for quality enhancement of printed-and-scanned image. We demonstrate both theoretically and practically how one can benefit from this sort of "distributed paper communications". (c) 2006 Elsevier B.V. All rights reserved.

关键词： data-hiding printed-and-scanned documents communications with side-information bar codes distributed coding joint source-channel coding Gel'fand-Pinsker problem Wyner-Ziv coding gray coding image enhancement

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Automatic image annotation based-on rough set theory with visual keys

Automatic image annotation based-on rough set theory with vi...

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International Symposium on Intelligent Signal processing and communications

作者： Serata, Manabu Hatakeyama, Yutaka Hirota, Kaoru Tokyo Inst Technol Midori Ku Yokohama Kanagawa 2268502 Japan

ISBN: (纸本)9780780397323

For automatic image annotation, a method based on rough sets with visual keys is proposed. Using rough set theory the method constructs decision rules about each visual key used for image indexing and about keywords from training set of already annotated images. Then target image is annotated according to constructed decision rules about visual keys which the target image is indexed by. The method is evaluated with training sets of 900 images and with test sets of 100 images on 1,000 manually annotated images in COREL database. Experiments show that recall rates tend to rise easily compared with precision rates on image retrieval with query-by-keywords.

关键词： Rough set theory

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An improved visual Cryptography scheme for secret hiding

An improved Visual Cryptography scheme for secret hiding

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23rd Biennial Symposium on communications

作者： Youmaran, R. Adler, A. Miri, A. Univ Ottawa Sch Informat Technol & Engn Ottawa ON Canada

ISBN: (纸本)9780780395275

visual Cryptography is based on cryptography where n images are encoded in a way that only the human visual system can decrypt the hidden message without any cryptographic computations when all shares are stacked together. This paper presents an improved algorithm based on Chang's and Yu visual cryptography scheme for hiding a colored image into multiple colored cover images. This scheme achieves lossless recovery and reduces the noise in the cover images without adding any computational complexity.

关键词： image processing visual Cryptography secret sharing

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Exploring the relationships of regions for visual content understanding

Exploring the relationships of regions for visual content un...

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Conference on visual communications and image processing 2008

作者： Liu, Ting Wang, Weiqiang Tian, Yonghong Huang, Tiejun Chinese Acad Sci Inst Comp Technol Beijing 100864 Peoples R China Chinese Acad Sci Grad Univ Beijing Peoples R China Peking Univ Inst Digital Media Beijing Peoples R China

ISBN: (纸本)9780819469946

An image can be considered as a collection of small regions. Most researches of image understanding extract features of these regions, and investigate relationships between these regions and keywords of images that are annotated manually. There are also some researches that explore the ontology of words. However, little attention has been paid to the relationships among regions in an image. In this paper, we make a close study of this type of relationships without the assumption that they are independent for visual content understanding. We first analyze the co-occurrence of regions using a statistical relevance probability model (SRP). Since human attention in the perception process of an image first focuses in one region and then moves on to other relevant regions, we propose a novel model called region sequence prediction model (RSP) to describe it. In RSP, annotation keywords for region sequences of the image and their probabilities are generated by a hidden Markov model. Experimental results of both image annotation and retrieval on the Corel dataset (an open image dataset) show that mining the relationships of image regions will achieve comparative or better performance in visual content understanding.

关键词： visual content understanding automatic image annotation statistical relevance prediction region sequence prediction Hidden Markov Model

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Generic content-based audio indexing and retrieval framework

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IEE PROCEEDINGS-VISION image AND SIGNAL processing 2006年第3期153卷 285-297页

作者： Kiranyaz, S. Gabbouj, M. Tampere Univ Technol Inst Signal Proc FIN-33101 Tampere Finland

Rapid increase in the amount of the digital audio collections presenting various formats, types, durations and other parameters that the digital multimedia world refers demands a generic framework for robust and efficient indexing and retrieval based on the aural content. Moreover, from the content-based multimedia retrieval point of view, the audio information can be even more important than the visual part as it is mostly unique and significantly stable within the entire duration of the content. A generic and robust audio-based multimedia indexing and retrieval framework, which has been developed and tested under the MUVIS system, is presented. This framework supports the dynamic integration of the audio feature extraction modules during the indexing and retrieval phases and therefore provides a test-bed platform for developing robust and efficient aural feature extraction techniques. Furthermore, the proposed framework is designed based on the high-level content classification and segmentation in order to improve the speed and accuracy of the aural retrievals. Both theoretical and experimental results are finally presented, including the comparative measures of retrieval performance with respect to the visual counterpart.

关键词： DIGITAL sound recording MULTIMEDIA systems INFORMATION retrieval DIGITAL communications EXPERIMENTAL design image retrieval

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Task Estimation Using Latent Semantic Analysis of visual Scenes and Spoken Words

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ELECTRONICS AND communications IN JAPAN 2014年第6期97卷 33-42页

作者： Kimura, Masashi Sawada, Shinta Iribe, Yurie Katsurada, Kouichi Nitta, Tsuneo Toyohashi Univ Technol Toyohashi Aichi Japan Toyohashi Univ Technol Informat & Media Ctr Toyohashi Aichi Japan

In this paper, we propose a task estimation method based on multiple subspaces extracted from multimodal information of image objects in visual scenes and spoken words in dialogue appearing in the same task. The multiple subspaces are obtained by using latent semantic analysis (LSA). In the proposed method, a task vector composed of spoken words and the frequencies of image-object appearances are extracted first, and then similarities among the input task vector and reference subspaces of different tasks are compared. Experiments are conducted on the identification of game tasks. The experimental results show that the proposed method with multimodal information outperforms the method in which only the single modality of image or spoken dialogue is applied. The proposed method achieves accurate performance even if less spoken dialogue is applied.

关键词： multimodal processing latent semantic analysis task estimation

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Robustness of a perceptually lossless medical image coder: Interpolation

Robustness of a perceptually lossless medical image coder: I...

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International Symposium on Intelligent Signal processing and communications

作者： Chai, Shan Wu, David Tan, Damian M. Wu, Hong Ren RMIT Univ Sch Elect & Comp Engn Melbourne Vic 3001 Australia

ISBN: (纸本)9780780397323

Perceptually lossless medical image coding is an alternative for compressing medical images. It provides a solution to the challenge of delivering clinically critical information in the shortest time possible. In this paper, an investigation of the robustness of the perceptually lossless image coder is carried out by applying bilinear, biquadratic and bicubic standard and centered B-spline interpolation filters. In order to evaluate the visual performance, a subjective assessment was conducted consisting or 30 medical images and 6 image processing experts. Here, the perceptually lossless medical image coder was compared to the state-of-the-art JPEG-LS compliant LOCO and NLOCO image coders. Current results have shown that overall, there were no perceivable differences or statistical significance when the medical images were enlarged by a factor of 2.

关键词： Interpolation

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Perception-based multi-quality image compression for efficient transmission

Perception-based multi-quality image compression for efficie...

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2006 International Symposium on Intelligent Signal processing and communications, ISPACS'06

作者： Rong, Mei Electrical Engineering Department Ryerson University Toronto ON M5B 2K3 Canada

ISBN: (纸本)0780397339

This paper proposes an efficient image compression algorithm based on visual perception. It automatically detects the important regions using saliency maps, then different regions are compressed in different qualities. Several adaptive methods are compared. This algorithm is expected to provide efficient image transmission through band-limited networks. © 2006 IEEE.

关键词： image compression

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