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Jointly optimized spatial prediction and block transform for video and image coding (2012)
| Venue: | IEEE Transactions on Image Processing |
| Citations: | 5 - 3 self |
BibTeX
@ARTICLE{Han12jointlyoptimized,
author = {Jingning Han and Student Member and Ankur Saxena and Vinay Melkote and Kenneth Rose},
title = {Jointly optimized spatial prediction and block transform for video and image coding},
journal = {IEEE Transactions on Image Processing},
year = {2012},
pages = {1874--1884}
}
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Abstract
Abstract—This paper proposes a novel approach to jointly optimize spatial prediction and the choice of the subsequent transform in video and image compression. Under the assumption of a separable first-order Gauss-Markov model for the image signal, it is shown that the optimal Karhunen-Loeve Transform, given available partial boundary information, is well approximated by a close relative of the discrete sine transform (DST), with basis vectors that tend to vanish at the known boundary and maximize energy at the unknown boundary. The overall intraframe coding scheme thus switches between this variant of the DST named asymmetric DST (ADST), and traditional discrete cosine transform (DCT), depending on prediction direction and boundary information. The ADST is first compared with DCT in terms of coding gain under ideal model conditions and is demonstrated to provide significantly improved compression efficiency. The proposed adaptive prediction and transform scheme is then implemented within the H.264/AVC intra-mode framework and is experimentally shown to significantly outperform the standard intra coding mode. As an added benefit, it achieves substantial reduction in blocking artifacts due to the fact that the transform now adapts to the statistics of block edges. An integer version of this ADST is also proposed. Index Terms—Blocking artifact, discrete sine transform (DST), intra-mode, spatial prediction, spatial transform. I.
Keyphrases
spatial prediction block transform image coding discrete sine transform separable first-order gauss-markov model traditional discrete cosine transform close relative adaptive prediction ideal model condition block edge novel approach image signal integer version added benefit image compression spatial transform transform scheme standard intra subsequent transform optimal karhunen-loeve transform available partial boundary information index term blocking artifact prediction direction basis vector known boundary substantial reduction boundary information avc intra-mode framework asymmetric dst compression efficiency overall intraframe unknown boundary
