Significance-linked connected component analysis for very low bit-rate wavelet video coding

Abstract

In recent years, a tremendous success in wavelet image coding has been achieved. It is mainly attributed to innovative strategies for data organization and representation of wavelet-transformed images. However, there have been only a few successful attempts in wavelet video coding. The most successful is perhaps Sarnoff Corp.'s zerotree entropy (ZTE) video coder. In this paper, a novel hybrid wavelet video coding algorithm termed video significance-linked connected component analysis (VSLCCA) is developed for very low bit-rate applications. There also has been empirical evidence that wavelet transform combined with those innovative data organization and representation strategies can be an invaluable asset in very low bit-rate video coding as long as motion compensated error frames are ensured to be free of blocking effect or coherent.In the proposed VSLCCA codec, first, fine-tuned motion estimation based on the H.263 Recommendation is developed to reduce temporal redundancy, and exhaustive overlapped block motion compensation is utilized to ensure coherency in motion compensated error frames. Second, wavelet transform is applied to each coherent motion compensated error frame to attain global energy compaction. Third, significant fields of wavelettransformed error frames are organized and represented as significance-linked connected components so that both the withinsubband clustering and the cross-scale dependency are exploited. Last, the horizontal and vertical components of motion vectors are encoded separately using adaptive arithmetic coding while significant wavelet coefficients are encoded in bit-plane order by using high order Markov source modeling and adaptive arithmetic coding.Experimental results on eight standard MPEG-4 test sequences show that for intraframe coding, on average the proposed codec exceeds H.263 and ZTE in peak signal-to-noise ratio by as much as 2.07 and 1.38 dB at 28 kbits, respectively. For entire sequence coding, VSLCCA is superior to H.263 and ZTE by 0.35 and 0.71 dB on average, respectively.

The impact of tree structures on the performance of zerotree-based wavelet video codecs

“…Inspired by the success of zero coding methods for compression of gray scale images, most of these algorithms are extended for coding of video sequences as well [15][16][17][18][19][20][21][22][23]. Essentially these codecs are based on either employing ME/MC in a closed-loop architecture [15][16][17][18][19] similar to the standard video codecs such as H.264/AVC [1] or employing ME/MC in an open loop manner to drive a temporal wavelet filter [20][21][22][23].…”

“…Essentially these codecs are based on either employing ME/MC in a closed-loop architecture [15][16][17][18][19] similar to the standard video codecs such as H.264/AVC [1] or employing ME/MC in an open loop manner to drive a temporal wavelet filter [20][21][22][23]. Although in the past both approaches have been used but lately there is more emphasis on wavelet video coding using motion compensated temporal filtering.…”

Optimal 3-d coefficient tree structure for 3-d wavelet video coding

“…Motivated by the success of the zerotree methods in image compression, researchers have extended nearly all of them from two-dimensional (2-D) to 3-D for video coding [2], [4], [11], [12], [17], [19], [20], [25], [27]- [29]. The basic structure of these codecs is relatively straightforward.…”

Low-rate video coding with block reordering in wavelet domain

“…(2) Motion Compensation: In SBR-SPIHT, OBMC of H.263 is used to reduce the overall energy of the motion-compensated residuals and the blocking effect at low bit-rates [3]- [4]. However, the blocking effect between inter/intra coded blocks is still serious because of different statistic properties.…”