based on the classical fractal video compression method, an improved object-based stereo video compression scheme with Shape-Adaptive DCT is proposed in this paper. Firstly, we use more effective macroblock partition ...
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based on the classical fractal video compression method, an improved object-based stereo video compression scheme with Shape-Adaptive DCT is proposed in this paper. Firstly, we use more effective macroblock partition scheme instead of classical quadtree partition scheme;thus reducing the block searching strategy. The stereo fractal video coding is proposed which matches the macroblock with two reference frames in left and right view results in increasing compression ratio and reducing bit rate when transmitting compressed stereo data. The stereo codec combines the Motion Compensation Prediction (MCP) and Disparity Compensation Prediction (DCP). Fractal coding is adopted and each object is encoded independently by a prior video segmentation alpha plane, which is defined exactly as in MPEG-4. The testing results with the nature monocular and stereo video sequences provide promising performances at low bit rate coding. We believe it will be a powerful and efficient technique for the object-based monocular and stereo video sequences coding. (C) 2014 Elsevier GmbH. All rights reserved.
In this paper, a rate-distortion based image segmentation algorithm for segmentation-basedcoding is presented using a recursive merging with region adjacency graph (RAG). In the method, the dissimilarity between a pa...
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In this paper, a rate-distortion based image segmentation algorithm for segmentation-basedcoding is presented using a recursive merging with region adjacency graph (RAG). In the method, the dissimilarity between a pair of adjacent regions is represented as a Lagrangian cost function considered in a rate-distortion sense. Lagrange multiplier is estimated in each merging step, a pair of adjacent regions whose cost is minimal is searched, and then the pair of regions are merged into a new region. The merging step is recursively performed until some termination criterion is reached. The proposed method thus is suitable for region- or segmentation-basedcoding. Experimental results for 256 x 256 Lena show that segmentation-basedcoding using the proposed method yields PSNR improvement of about 3.5 similar to4.5 dB, 1.8 similar to2.0 dB, and 1.2 similar to1.5 dB over mean-difference based method, distortion-based method, and JPEG, respectively.
An efficient segmentation algorithm for region-based coding is proposed. A new connected operator based on both size and contrast is presented and an efficient region merging algorithm which preserves high quality in ...
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An efficient segmentation algorithm for region-based coding is proposed. A new connected operator based on both size and contrast is presented and an efficient region merging algorithm which preserves high quality in terms of the number of regions is proposed. Experimental results show that the proposed algorithm achieves a good performance in terms of the image quality and the number of regions.
We propose a scheme for coding subregions in video scenes to provide content-based scalable video. For each region, a special color is used to represent the nonobject area, and the resulting frames are coded using con...
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We propose a scheme for coding subregions in video scenes to provide content-based scalable video. For each region, a special color is used to represent the nonobject area, and the resulting frames are coded using conventional video coding algorithms. At the decoder, the region shape is recovered based on chroma keying, and hence, content-based manipulations are made possible. A number of techniques that eliminate boundary artifacts common to region-based coding are presented. In this scheme, no explicit shape coding is needed, and advantages of existing coding algorithms are retained. This scheme was submitted to ISO MPEG-4 and performed very well in the subjective tests.
region-based functionality offered by the MPEG-4 video compression standard is also appealing for still images, for example to permit object-based queries of a still-image database. A popular method for still-image co...
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region-based functionality offered by the MPEG-4 video compression standard is also appealing for still images, for example to permit object-based queries of a still-image database. A popular method for still-image compression is fractal coding. However, traditional fractal image coding uses rectangular range and domain blocks. Although new schemes have been proposed that merge small blocks into irregular shapes, the merging process does not, in general, produce semantically-meaningful regions. We propose a new approach to fractal image coding that permits region-based functionalities;images are coded region by region according to a previously-computed segmentation map. We use rectangular range and domain blocks, but divide boundary blocks into segments belonging to different regions. Since this prevents the use of standard dissimilarity measure, we propose a new measure adapted to segment shape. We propose two approaches: one in the spatial and one in the transform domain. While providing additional functionality, the proposed methods perform similarly to other tested methods in terms of PSNR but often result in images that are subjectively better. Due to the limited domain-block code-book size, the new methods are faster than other fractal coding methods tested. The results are very encouraging and show the potential of this approach for various internet and still-image database applications.
Modern holography for 3D imaging allows to reconstruct all the parallaxes that are needed for a truly immersive visualization. Nevertheless, it possesses huge amount of data which induces higher transmission and stora...
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Modern holography for 3D imaging allows to reconstruct all the parallaxes that are needed for a truly immersive visualization. Nevertheless, it possesses huge amount of data which induces higher transmission and storage requirements. To gain more popularity and acceptance, digital holography demands development of efficient coding schemes that provide significant data compression at low computation cost. Another issue that needs to be tackled when designing holography coding algorithms is interoperability with commonly used formats. In light of this, the upcoming JPEG Pleno standard aims to develop a standard framework for the representation and exchange of new imaging modalities such as holographic imaging while maintaining backward compatibility with the legacy JPEG decoders. This paper summarizes the early work on lossy compression of computer graphic holograms and analyses the efficiency of additional methods that may exhibit good satisfactory coding performance while considering the backward compatibility with legacy JPEG decoders. To validate our findings, the results of our tests are shown and interpreted. Finally, we also outline the emerging trends for future researches.
region-based video coding schemes employed in MPEG-4 are also promising for still image coding applications where images contain a number of objects that can be encoded at different bit rates, such as compression of m...
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region-based video coding schemes employed in MPEG-4 are also promising for still image coding applications where images contain a number of objects that can be encoded at different bit rates, such as compression of medical images for archiving and transmission. Motivated by this fact, in this letter we investigate multiregion multiquality (MRMQ) coding with quadtree-based wavelet coders. We present a novel scheme which addresses the region size sensitivity problem in region-based coding. The proposed method outperforms the region-of-interest (ROI) coding unit of JPEG-2000;it is possible to save 0.3 bits per pixel to attain the same ROI/background fidelity without sacrificing the additional features provided by JPEG-2000, such as resolution scalability and error resilience.
This paper proposes a fast segmentation method for still image based on a hybrid of clustering and morphological segmentation approach. The objective of the clustering is to partition an input image into a number of c...
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This paper proposes a fast segmentation method for still image based on a hybrid of clustering and morphological segmentation approach. The objective of the clustering is to partition an input image into a number of clusters such that the gray levels within each cluster are similar. The clustered image is further processed by using morphological segmentation approach, in which a seeded region growing however plays a role of the decision tool instead of a watershed algorithm for a remarkable improvement of processing time. The performance of the proposed method is evaluated by comparing its region-based coding results with those of the morphological watershed-based segmentation method and the split-and-merge algorithm. The experiments results showed that region-based coding using the proposed algorithm yields PSNR improvement of about 1.5 dB over the morphological watershed-based method. Especially, the total time elapsed to segment an image using the proposed method is reduced about 1/6 and 1/3 compared with those of the watershed-based segmentation and the split-and-merge methods, respectively.
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