Image encoding/decoding method and apparatus, and recording medium for storing bitstream that involves performing intra prediction using constructed reference sample

Abstract

An image encoding/decoding method is disclosed. A method of decoding an image, the method comprising, deriving an intra prediction mode for a current block, decoding at least one original sample that is present in a rightmost column and a bottommost row (a bottom row) of the current block, constructing a reference sample by using the at least one decoded original sample and performing intra prediction on the current block by using the constructed reference sample.

1 . An image decoding method performed by an image decoding apparatus, comprising:
 deriving an intra prediction mode of a current block;   deriving reference samples of the current block; and   performing an intra prediction on the current block by using the intra prediction mode and the reference samples,   wherein deriving the reference samples of the current block comprises:   applying filtering to the reference samples,   wherein the strength of the filtering applied to the reference samples is determined based on the intra prediction mode of the current block and a size of the current block.   
     
     
         2 . The method of  claim 1 ,
 wherein the reference samples are derived based on an availability of each of the reference samples.   
     
     
         3 . The method of  claim 1 ,
 wherein the reference samples comprise samples included in at least one of a reference sample line adjacent to a left side of the current block and a reference sample line adjacent to an upper side of the current block.   
     
     
         4 . The method of  claim 3 ,
 wherein the filtering applied to the reference samples is applied to samples included in at least one of the reference sample line adjacent to the left side of the current block and the reference sample line adjacent to the upper side of the current block.   
     
     
         5 . An image encoding method performed by an image encoding apparatus, comprising:
 deriving an intra prediction mode of a current block;   deriving reference samples of the current block; and   performing an intra prediction on the current block by using the intra prediction mode and the reference samples,   wherein deriving the reference samples of the current block comprises:   applying filtering to the reference samples,   wherein the strength of the filtering applied to the reference samples is determined based on the intra prediction mode of the current block and a size of the current block.   
     
     
         6 . The method of  claim 5 ,
 wherein the reference samples are derived based on an availability of each of the reference samples.   
     
     
         7 . The method of  claim 5 ,
 wherein the reference samples comprise samples included in at least one of a reference sample line adjacent to a left side of the current block and a reference sample line adjacent to an upper side of the current block.   
     
     
         8 . The method of  claim 7 ,
 wherein the filtering applied to the reference samples is applied to samples included in at least one of the reference sample line adjacent to the left side of the current block and the reference sample line adjacent to the upper side of the current block.   
     
     
         9 . A non-transitory computer readable recording medium storing a bitstream that is generated by an image encoding method performed by an image encoding apparatus, the image encoding method comprising:
 deriving an intra prediction mode of a current block;   deriving reference samples of the current block; and   performing an intra prediction on the current block by using the intra prediction mode and the reference samples,   wherein deriving the reference samples of the current block comprises:   applying filtering to the reference samples,   wherein the strength of the filtering applied to the reference samples is determined based on the intra prediction mode of the current block and a size of the current block.