Primary transforms for cross-component level reconstruction
摘要
說(shuō)明書
Turning to coding and decoding (entropy coding) of transform coefficients of residuals in each of the color component, for each transform block, transform coefficient coding may start with signaling of the skip sign, followed by the transform kernel type and the end-of-block (EOB) position when the skip sign is zero (indicating there are nonzero coefficients). Then each coefficient value is mapped to multiple level maps (amplitude map) and the sign.
After the EOB position is coded, the lower-level map and the middle-level map may be coded in reverse scan order, the former indicating if the coefficient magnitude is within a low level (e.g., between 0 and 2) while the latter indicating if the range is within a middle level (e.g., between 3 and 14). The next step codes, in the forward-scanning order, the sign of the coefficients as well as the residual values of the coefficient larger than a high level (e.g., 14) by, for example, Exp-Golomb code.
