共查询到18条相似文献,搜索用时 62 毫秒
1.
This paper proposes a motion-based region growing segmentation scheme for the object-based video coding, which segments an image into homogeneous regions characterized by a coherent motion. It adopts a block matching algorithm to estimate motion vectors and uses morphological tools such as open-close by reconstruction and the region-growing version of the watershed algorithm for spatial segmentation to improve the temporal segmentation. In order to determine the reliable motion vectors, this paper also proposes a change detection algorithm and a multi-candidate pro- screening motion estimation method. Preliminary simulation results demonstrate that the proposed scheme is feasible. The main advantage of the scheme is its low computational load. 相似文献
2.
Aperture-dependent motion compensation is important for wide beam Synthetic Aperture Radar (SAR) data processing. This paper studies a wide beam motion compensation algorithm based on frequency division. It takes blocks along azimuth dimension in frequency domain and applies angle-variant motion compensation in time domain. With this frequency division based motion compensation approach, the effects of aperture-dependent residual phase errors are corrected precisely. The rationale and procedure of this algorithm are introduced in detail. Point targets and images of a P-band airborne SAR with motion errors are simulated to validate this algorithm. Compared with the wide beam motion compensation algorithms based on time division, the proposed algorithm has better performance, especially in terms of high-frequency motion errors. 相似文献
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ZHANG Fan WANG Xiao-tong XU Xiao-gang YANG Chang-qing 《光电子快报》2007,3(4):308-311
An algorithm using fixed-lag smooth filtering to improve the precision of EIS algorithm is presented in this paper. Firstly, gray projection algorithm (GPA) is used to calculate the interframe global motion vectors. Secondly, the fixed-lag smooth filter is used to smoothen the motion track of the original video sequence, according to different motion models. At last, the original sequence is compensated by using the compensation vectors calculated from filtering. This algorithm has been proved superior in filtering precision by experiments of video sequences in different motion scenes. This algorithm also satisfies the real-time request. 相似文献
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CHEN Gang JIA Zhen-hong CHEN He 《光电子快报》2008,4(1):66-68
A fast quarter-pixel motion estimation algorithm is proposed in this paper. The proposed algorithm based on mathematical models of the motion compensated prediction errors. Unlike conventional quarter-pixel accurate motion estimation algorithm, proposed algorithm can avoid fractional-pixel interpolation and subsequent fracfional-pixel search after integer-precision motion estimation. Experiments show that the proposed algorithm greatly reduces the computational complexity of quarterpixel motion estimation, while keeping the nearly equal quality of the image 相似文献
5.
A fast half-pixel motion estimation algorithm and its corresponding hardware architecture are presented. Unlike three steps are needed in typical half-pixel motion estimation algorithm, the presented algorithm needs only two steps to obtain all the interpolated pixels of an entire 8′8 block. The proposed architecture works in a parallel way and is simulated by Modelsim 6.5 SE, synthesized to the Xilinx Virtex4 XC4VLX15 Field Programmable Gate Array(FPGA) device, and verified by hardware platform. The implementation results show that this architecture can achieve 190 MHz and 11 clock cycles are reduced to complete the entire interpolation process in comparison with typical half-pixel interpolation, which meets the requirements of real-time application for very high defination videos. 相似文献
6.
Hu Weiwei Zhang Qishan 《电子科学学刊(英文版)》2008,25(1):125-128
Motion estimation is an important part of H.264/AVC encoding progress, with high computational complexity. Therefore, it is quite necessary to find a fast motion estimation algorithm for real-time applications. The algorithm proposed in this letter adjudges the macroblocks activity degree first; then classifies different video sequences, and applies different search strategies according to the result. Experiments show that this method obtains almost the same video quality with the Full Search (FS) algorithm but with reduced more than 95% computation cost. 相似文献
7.
Wang Yujian Gao Jianpo Yang Hao Wu Zhenyang 《电子科学学刊(英文版)》2007,24(5):668-673
Video object extraction is a key technology in content-based video coding.A novel video object extracting algorithm by two Dimensional (2-D) mesh-based motion analysis is proposed in this paper.Firstly,a 2-D mesh fitting the original frame image is obtained via feature detection algorithm. Then,higher order statistics motion analysis is applied on the 2-D mesh representation to get an initial motion detection mask.After post-processing,the final segmenting mask is quickly obtained.And hence the video object is effectively extracted.Experimental results show that the proposed algorithm combines the merits of mesh-based segmenting algorithms and pixel-based segmenting algorithms,and hereby achieves satisfactory subjective and objective performance while dramatically increasing the segmenting speed. 相似文献
8.
AN ALGORITHM OF MOTION ESTIMATION BASED ON UNIT QUATERNION DECOMPOSITION OF THE ROTATION MATRIX 总被引:1,自引:0,他引:1
Huang Yu Yuan Baozong 《电子科学学刊(英文版)》1996,13(4):289-295
Based on the unit quaternion decomposition of rotation matrix, this paper puts forward an algorithm to estimate motion parameters from the space position vectors of 3D feature points. Rotation matrix's representation with the unit quaternion has no singular points, so the unit quaternion-based estimation method is of more practical importance, and the algorithm in this paper does not need iteration computation compared to those unit quaternion-based methods proposed by Horn(1987) and Su, et al.(1989). Solution's uniqueness analysis of the algorithm and simulation experiment results are also presented, it can be seen that performance of our method is satisfactory. 相似文献
9.
Side information has a significant influence on the rate-distortion(RD) performance of distributed video coding(DVC). In the conventional motion compensated frame interpolation scheme, all blocks adopt the same side-information generation method regardless of the motion intensity inequality at different regions. In this paper, an improved method is proposed. The image blocks are classified into two modes, fast motion and slow motion, by simply computing the discrete cosine transformation(DCT) coefficients at the encoder. On the decoder, it chooses the direct interpolation and refined motion compensated interpolation correspondingly to generate side information. Experimental results show that the proposed method, without increasing the encoder complexity, can increase the average peak signal-to-noise ratio(PSNR) by up to 1~ 2 dB compared with the existing algorithm. Meanwhile, the proposed algorithm significantly improves the subjective quality of the side information. 相似文献
10.
WangHui 《电子科学学刊(英文版)》2002,19(4):426-430
In this letter,drawbacks of the classical algorithm to enhance the fuzzy contrast among adjacent regions are analyzed.Based on it ,a new fuzzy enhancement algorithm and a linear fuzzy distribution that maps the gray images to corresponding generalized fuzzy set are proposed.Results of two examples illustrate that the algorithm is more effective and faster when used to detect the multi-level edges of images. 相似文献
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帧率上采样作为一种视频后处理技术,通过对原始视频插值得到高帧率视频,满足人们对高帧率视频的需求.传统基于重叠块的插值补偿算法会带来块效应或鬼影现象.为了解决这一问题,人们提出联合匹配块及其相邻块预测的方法,但是复杂度高,效果不明显.基于以上几点,本文提出一种自适应联合相邻运动矢量的运动补偿插值算法(Joint Motion-Compensated In-terpolation Algorithm Using Adjacent Block Motion Vectors Adaptively,AJ-MCI).在该算法中,将运动矢量矫正和运动补偿插值算法相结合,同时运动补偿模块中自适应地联合相邻匹配块,以最大限度刻画真实运动轨迹.实验结果表明,本文算法能很好的提升视频的主客观质量,同时保持较低计算复杂度. 相似文献
13.
Temporal error concealment using motion field interpolation 总被引:3,自引:0,他引:3
An error concealment algorithm based on motion field interpolation is presented. For each pixel in a damaged block, the algorithm recovers a motion vector using bilinear interpolation of neighbouring motion vectors. This vector is then used to conceal the damaged pixel. Overlapped motion compensation is used to combine this algorithm with a boundary matching error concealment algorithm. Simulation results demonstrate the superior performance of the proposed algorithms 相似文献
14.
针对UMHexagon S算法存在的问题,提出了一种改进的UMHexagon S算法。算法充分利用运动矢量的中心偏置特性与运动同质性,采用递增数列步长的对称十字型搜索模板和多层次八边形搜索模板以减少无用的搜索点,根据运动矢量的变化趋势自适应地确定多层次八边形的搜索方向,用16点井字型搜索代替5×5全搜索,并改善了运动估计的粗定位。实验结果表明,与UMHexagon S算法相比,改进算法在保证PSNR和比特率基本不变的前提下,平均减少了18.53%的运动估计时间,尤其是对大运动视频序列的效果更好,最大可以减少25.17%的运动估计时间。 相似文献
15.
Shen-Chuan Tai Ying-Ru Chen Yu-Hung Chen 《Signal Processing: Image Communication》2007,22(10):877-890
A good fast motion search algorithm should efficiently speed up the encoding time and keep the quality of encoded video stable at the same time. Researches have shown that many fast algorithms lose the quality requirement in some special video sequences. These video sequences often have heavy motions and need large search windows for motion vector search. E3SS, DS, and E-HEXBS, which are famous algorithms, are not good enough in these sequences. As to UMHexagonS, it is able to meet the high video quality requirement very well, but it costs too much computation. This paper introduces a multi-stage motion estimation algorithm. The algorithm ensures getting good video quality while decreases the motion search time efficiently. It divides the search regions into many un-overlapped small-diamond regions and forces the motion search to go outward for larger motion vectors. This method is also designed to avoid mistaking local optimal motion vectors. For this reason, the selected motion vector is refined by several stages. Experimental results show that the proposed algorithm uses almost the same number of checking points as E3SS but achieves a better quality. Furthermore, the proposed algorithm is also tested in H.264/AVC JM9.5 encoder; the experimental results show that this algorithm is also suitable for variable block-size motion estimation. 相似文献
16.
A complexity-bounded motion estimation algorithm 总被引:5,自引:0,他引:5
The full search motion estimation algorithm for video coding is a procedure of high computational cost. For this reason, in real-time low-power applications, low-cost motion estimation algorithms are viable solutions. A novel reduced complexity motion estimation algorithm is presented. It conjugates the reduction of computational load with good encoding efficiency. It exploits the past history of the motion field to predict the current motion field. A successive refinement phase gives the final motion field. This approach leads to a sensible reduction in the number of motion vector that have to be tested. The complexity is lower than any other algorithm algorithms known to the authors, in the literature, it is constant as there is no recursivity in the algorithm and independent of any search window area size. Experimental evaluations have shown the robustness of the algorithm when applied on a wide set of video sequences-a good performance compared to other reduced complexity algorithms and negligible loss of efficiency versus the full search algorithm. 相似文献
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