Image encoding/decoding method and apparatus using intra-screen prediction

Abstract

Disclosed is a decoding method which uses an intra-screen prediction. A decoding method which uses an intra prediction performed in a decoding apparatus comprises the steps of: receiving a bit stream; obtaining decoding information from the received bit stream; generating a prediction block for a current block to be decoded using the obtained decoding information; and restoring the current block by adding a residual block obtained from the bit stream and the prediction block. Accordingly, a compression ratio of an image can be improved.

1 . A method of decoding a coded image with a decoding apparatus, comprising:
 restoring a residual block of a current block in the coded image, by decoding a bitstream including the coded image;   determining an intra prediction mode of the current block, from a plurality of intra prediction modes supported in the decoding apparatus;   obtaining a prediction block for the current block, based on the determined intra prediction mode; and   restoring the current block, based on the residual block and the prediction block for the current block,   wherein a number of the intra prediction modes supported in the decoding apparatus is 67.   
     
     
         2 . The method of  claim 1 , wherein the plurality of the intra prediction modes include 2 non-directional modes and 65 directional modes. 
     
     
         3 . The method of  claim 1 , wherein the plurality of the intra prediction modes is variably determined based on a shape of the current block. 
     
     
         4 . The method of  claim 3 , wherein the plurality of the intra prediction modes include first directional modes between a bottom-left diagonal mode and a top-left diagonal mode and second directional modes between the top-left diagonal mode and a top-right diagonal mode. 
     
     
         5 . The method of  claim 4 , wherein when a width of the current block is greater than a height of the current block, a number of the first directional modes is less than a number of the second directional modes. 
     
     
         6 . The method of  claim 4 , wherein when a width of the current block is less than a height of the current block, a number of the first directional modes is greater than a number of the second directional modes. 
     
     
         7 . The method of  claim 1 , wherein the current block is obtained through a tree structure-based block division, and
 wherein the tree structure-based block division includes at least one of a quad tree division or a binary tree division.   
     
     
         8 . The method of  claim 7 , wherein the binary tree division is performed based on a pre-determined division information, and
 wherein the division information includes a first flag whether to divide based on the binary tree division and a second flag whether to divide in a vertical direction or in a horizontal direction.   
     
     
         9 . A method of encoding an image with an encoding apparatus, comprising:
 determining an intra prediction mode of a current block in the image, from a plurality of intra prediction modes supported in the encoding apparatus;   obtaining a prediction block for the current block, based on the determined intra prediction mode;   obtaining a residual block for the current block, based on an original block for the current block and the obtained prediction block; and   generating a bitstream by encoding the residual block,   wherein a number of the intra prediction modes supported in the encoding apparatus is 67.   
     
     
         10 . A non-transitory computer readable medium having stored thereon instructions that when executed by a processor perform a method, comprising:
 restoring a residual block of a current block in the coded image, by decoding a bitstream including the coded image;   determining an intra prediction mode of the current block, from a plurality of intra prediction modes supported in the decoding apparatus;   obtaining a prediction block for the current block, based on the determined intra prediction mode; and   restoring the current block, based on the residual block and the prediction block for the current block,   wherein a number of the intra prediction modes supported in the decoding apparatus is 67.