×

Method and apparatus for encoding residual block, and method and apparatus for decoding residual block

  • US 10,171,826 B2
  • Filed: 02/11/2015
  • Issued: 01/01/2019
  • Est. Priority Date: 10/28/2009
  • Status: Active Grant
First Claim
Patent Images

1. An apparatus for decoding an image, the apparatus comprising:

  • a splitter which splits the image into a plurality of maximum coding units, hierarchically splits a maximum coding unit among the plurality of maximum coding units into a plurality of coding units based on split information of a coding unit, and determines a transformation residual block from a coding unit among the plurality of coding units based on split information of the transformation residual block, wherein the transformation residual block includes a plurality of sub residual blocks;

    a parser which obtains, from a bitstream, a coded block flag indicating whether the transformation residual block includes at least one non-zero effective transformation coefficient,when the coded block flag indicates that the transformation residual block includes at least one non-zero effective transformation coefficient, determines whether a current sub residual block is a left-upper residual block among a plurality of sub residual blocks in the transformation residual block,when the current sub residual block is a left-upper sub residual block, obtains transformation coefficients of the left-upper sub residual block based on a significance map indicating a location of a non-zero transformation coefficient in the first sub residual block and level information of the non-zero transformation coefficient in the first sub residual block obtained from the bitstream,when the current sub residual block is not a left-upper sub residual block, obtains, from the bitstream, an effective coefficient flag of the current sub residual block without considering an effective coefficient flag of another sub residual block, the effective coefficient flag of the current sub residual block indicating whether at least one non-zero effective transformation coefficient exists in the current sub residual block,when the effective coefficient flag indicates that at least one non-zero transformation coefficient exists in the current sub residual block, obtains transformation coefficients of the current sub residual block based on a significance map indicating a location of the non-zero transformation coefficient in the current sub residual block and level information of the non-zero transformation coefficient in the current sub residual block obtained from the bitstream;

    when the effective coefficient flag indicates that the at least one non-zero effective transformation coefficient does not exist in the current sub residual block, determines the transformation coefficients of the current second sub residual blocks as zero; and

    an inverse-transformer which performs inverse-transformation on the transformation residual block including the current sub residual block,wherein the transformation coefficients of the current sub residual block are a subset of transformation coefficients of the transformation residual block,the transformation coefficients of the current sub residual block are obtained after or before transformation coefficients of another sub residual block among the plurality of sub residual blocks in the transformation residual block,wherein a level information of a non-zero transformation coefficient includes information regarding a sign and an absolute value of the non-zero transformation coefficient,when the split information of the coding unit of a current depth indicates a split, the coding unit of the current depth is split into the plurality of coding units of the lower depth, independently from neighboring coding units,when the split information of the coding unit of the current depth indicates a non-split, one or more transformation residual blocks including the transformation residual block are obtained from the coding unit of the current depth, andwherein the current sub residual block is one of a plurality of sub residual blocks which have same size with each other and square-shape, and are included in the transformation residual block.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×