This paper presents an efficient architecture of binary motion estimation (BME) for MPEG-4 shape coding. This architecture, called DDBME, mainly consists of a data dispatch based 1-D systolic array and a 16x32 bit sea...
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ISBN:
(纸本)0819439886
This paper presents an efficient architecture of binary motion estimation (BME) for MPEG-4 shape coding. This architecture, called DDBME, mainly consists of a data dispatch based 1-D systolic array and a 16x32 bit search range buffer. In DDBME, bit parallelism technique is applied on the SAD calculation of block matching algorithm. In order to support efficiently bit-data parallel processing, bit addressing should be taken into consideration. The data dispatch technique is applied on 1-D array by the hardwired data flow routing such that the bit addressing operations can be efficiently reduced. The DDBME operating at 7.29 MHz can handle the real-time requirement for encoding MPEG-4 shape sequence at core profile level 2, i.e. 2 VOs with CIF format, 30 fps and assuming each frame contains 30% boundary macroblocks in average. For the same real-time specification, the optimized software running on RISC (Ultra Spare, 300MHz) can only achieve 1/20 performance.
Geometric distortion measurement and the associated metrics involved are integral to the Rate Distortion (RD) shape coding framework, with importantly the efficacy of the metrics being strongly influenced by the under...
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Geometric distortion measurement and the associated metrics involved are integral to the Rate Distortion (RD) shape coding framework, with importantly the efficacy of the metrics being strongly influenced by the underlying measurement strategy. This has been the catalyst for many different techniques with this article presenting a comprehensive review of geometric distortion measurement, the diverse metrics applied, and their impact on shape coding. The respective performance of these measuring strategies is analyzed from both a RD and complexity perspective, with a recent distortion measurement technique based on arc-length-parameterization being comparatively evaluated. Some contemporary research challenges are also investigated, including schemes to effectively quantify shape deformation.
In this paper, we propose a new vertex adjustment method which is based on the size ratio of an object and that of a polygon. In the conventional polygonal approximation methods, the sizes of an object and an approxim...
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In this paper, we propose a new vertex adjustment method which is based on the size ratio of an object and that of a polygon. In the conventional polygonal approximation methods, the sizes of an object and an approximating polygon are quite different, therefore there are so many error pixels between them. The proposed method reduces the size of error regions by adjusting the size of the polygon to that of an object. Simulation results show outstanding performance of the proposed method.
The intention of shape coding in the MPEG-4 is to improve the coding efficiency as well as to facilitate the object-oriented applications, such as shape-based object recognition and retrieval. These require both effic...
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The intention of shape coding in the MPEG-4 is to improve the coding efficiency as well as to facilitate the object-oriented applications, such as shape-based object recognition and retrieval. These require both efficient shape compression and effective shape description. Although these two issues have been intensively investigated in data compression and pattern recognition fields separately, it remains an open problem when both objectives need to be considered together. To achieve high coding gain, the operational rate-distortion optimal framework can be applied, but the direction restriction of the traditional eight-direction edge encoding structure reduces its compression efficiency and description effectiveness. We present two arbitrary direction edge encoding structures to relax this direction restriction. They consist of a sector number, a short component, and a long component, which represent both the direction and the magnitude information of an encoding edge. Experiments on both shape coding and hand gesture recognition validate that our structures can reduce a large number of encoding vertices and save up to 48.9% bits. Besides, the object contours are effectively described and suitable for the object-oriented applications. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.
In this paper, we address the problem of the efficient encoding of object boundaries. This problem is becoming increasingly important in applications such as content-based storage and retrieval, studies and television...
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In this paper, we address the problem of the efficient encoding of object boundaries. This problem is becoming increasingly important in applications such as content-based storage and retrieval, studies and television postproduction, and mobile multimedia applications. The MPEG-4 visual standard will allow the transmission of arbitrarily shaped video objects. The techniques developed for shape coding within the MPEG-4 standardization effort are described and compared first. A framework for the representation of shapes using their contours is presented next. Such representations are achieved using curves of various orders, and they are optimal in the rate-distortion sense. Last, conclusions are drawn.
This paper describes a unified framework of bit-rate control for binary and gray-level shape coding. An exponential rate-distortion model is proposed for binary shape and used in the bit-rate control. An approximation...
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This paper describes a unified framework of bit-rate control for binary and gray-level shape coding. An exponential rate-distortion model is proposed for binary shape and used in the bit-rate control. An approximation method is applied for finer distortion scale adjustment by adjusting the conversion ratio at the binary alpha block level. Since the gray-level shape is encoded as its support information and the alpha plane information, the rate-quantizer relationship of the alpha plane is modeled. The bit-rate control is then able to adjust the quantizer of the alpha plane for the bit-rate control purpose. The extension for video object (VO) coding is also studied. In this bit-rate control approach, a buffer feedback controller is employed to determine the target bit rates for different sources, i.e., binary shape, gray-level shape, and texture. Accordingly, the distortion scales of different sources are adjusted based on their rate-distortion relationships to maintain a stable encoder buffer. The advantages of the proposed method are demonstrated through various tests for different scenarios. Overall, the algorithm can efficiently encode the shape information and shows a good performance for VO coding.
This paper proposes a modified shape coding algorithm called modified vertex based shape coding (MVBSC) to encode the boundary of a visual object compactly by using a modified polygonal approximation approach which u...
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This paper proposes a modified shape coding algorithm called modified vertex based shape coding (MVBSC) to encode the boundary of a visual object compactly by using a modified polygonal approximation approach which uses modified curvature scale space (CSS) theory to extract feature points.
Existing operational rate-distortion shape coding aims at finding a polygon which can be encoded with the lowest bit rate under a given upper bound on the edge error. However, this upper bound may cause noticeable err...
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ISBN:
(纸本)9781479957521
Existing operational rate-distortion shape coding aims at finding a polygon which can be encoded with the lowest bit rate under a given upper bound on the edge error. However, this upper bound may cause noticeable errors. Therefore, we add an l_2-norm error regularization term to the objective function, and seek the globally optimal solution using a shortest path algorithm for a weighted directed acyclic graph. Experiments confirm the accuracy and robustness of our method.
This paper presents a novel fast motion estimation (ME) algorithm for shape coding in MPEG-4, which takes full advantage of the correlation between adjacent binary alpha blocks (BABs) and the match characteristics of ...
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This paper presents a novel fast motion estimation (ME) algorithm for shape coding in MPEG-4, which takes full advantage of the correlation between adjacent binary alpha blocks (BABs) and the match characteristics of boundary BABs. Compared with the ME algorithm for shape coding in MPEG-4 verification model and other improved algorithms, the proposed algorithm significantly speeds the ME process and takes equal bit rate.
In this paper, we propose a new shape-coding algorithm called wavelet-based shape coding (WBSC). Performing wavelet transform on the orientation of original planar curve gives the corners called corner-1 points and en...
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In this paper, we propose a new shape-coding algorithm called wavelet-based shape coding (WBSC). Performing wavelet transform on the orientation of original planar curve gives the corners called corner-1 points and end of arcs that belong to the original curve. Each arc is represented by a broken line and the corners called corner-2 points of the broken line are extracted. A polygonal approximation of a contour is an ordered list of corner-1 points, ends of arcs and corner-2 points which are extracted by using the above algorithm. All of the points are called polygonal vertices which will be compressed by our adaptive arithmetic encoding. Experimental results show that our method reduces code bits by about 26% compared with the context-based arithmetic encoding (CAE) of MPEG-4, and the subjective quality of the reconstructed shape is better than that of CAE at the same Dn.
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