In this paper, we propose a sparse overcomplete image approximation method based on the ideas of overcomplete log-Gabor wavelet, mean shift and energy concentration. The proposed approximation method selects the neces...In this paper, we propose a sparse overcomplete image approximation method based on the ideas of overcomplete log-Gabor wavelet, mean shift and energy concentration. The proposed approximation method selects the necessary wavelet coefficients with a mean shift based algorithm, and concentrates energy on the selected coefficients. It can sparsely approximate the original image, and converges faster than the existing local competition based method. Then, we propose a new compression scheme based on the above approximation method. The scheme has compression performance similar to JPEG 2000. The images decoded with the proposed compression scheme appear more pleasant to the human eyes than those with JPEG 2000.展开更多
In this paper,a new fast mode-selection ap-proach is proposed.This algorithm combines the proposed approaches of mode pre-decision and precise large-small mode decision,by selecting the best mode efficiently.Ex-perime...In this paper,a new fast mode-selection ap-proach is proposed.This algorithm combines the proposed approaches of mode pre-decision and precise large-small mode decision,by selecting the best mode efficiently.Ex-perimental results show that the proposed approach can re-duce the computational cost of full search and fast multi-block motion estimation by 80%and 45%,respec-tively,with similar visual quality and bit rate.The proposed algorithm also reduces by 75%the computational cost of the large-small mode isolation algorithm for low-motion sequence coding,and with 0.06 PSNR gain and 3.7%re-duction in bit rate.展开更多
文摘In this paper, we propose a sparse overcomplete image approximation method based on the ideas of overcomplete log-Gabor wavelet, mean shift and energy concentration. The proposed approximation method selects the necessary wavelet coefficients with a mean shift based algorithm, and concentrates energy on the selected coefficients. It can sparsely approximate the original image, and converges faster than the existing local competition based method. Then, we propose a new compression scheme based on the above approximation method. The scheme has compression performance similar to JPEG 2000. The images decoded with the proposed compression scheme appear more pleasant to the human eyes than those with JPEG 2000.
文摘In this paper,a new fast mode-selection ap-proach is proposed.This algorithm combines the proposed approaches of mode pre-decision and precise large-small mode decision,by selecting the best mode efficiently.Ex-perimental results show that the proposed approach can re-duce the computational cost of full search and fast multi-block motion estimation by 80%and 45%,respec-tively,with similar visual quality and bit rate.The proposed algorithm also reduces by 75%the computational cost of the large-small mode isolation algorithm for low-motion sequence coding,and with 0.06 PSNR gain and 3.7%re-duction in bit rate.
