Additive Vector Decoding of Transform

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【作者】 Wai Tuck Wu,Allen Gersho 

【摘要】In a standard transform coding scheme of images or video; the decoder can be implemented by a table-lookup technique without the explicit use of an inverse transformation. In this new decoding method; each received code index of a transform coe cient addresses a particular codebook to fetch a component code vector that resembles the basis vector of the linear transformation. The output image is then reconstructed by summing a small number of non-zero component code vectors. With a set of well-designed codebooks; this new decoder can exploit the correlation among the quantized transform coe cients to achieve better rate-distortion performance than the conventional decoding method. An iterative algorithm for designing a set of locally optimal codebooks from a training set of images is presented. We demonstrate that this new idea can be applied to decode improved quality pictures from the bit stream generated from a standard encoding scheme of still images or video; while the complexity is low enough to justify practical implementation.