Method and apparatus for image encoding/decoding, and recording medium storing bitstream

Abstract

An image encoding/decoding method and apparatus for performing intra prediction mode based intra prediction are provided. An image decoding method may comprise decoding an intra prediction mode of a current block, deriving at least one intra prediction mode from the decoded intra prediction mode of the current block, generating two or more intra prediction blocks using the intra prediction mode of the current block and the derived intra prediction mode, and generating an intra prediction block of the current block based on the two or more intra prediction blocks.

1 . An image decoding method performed by a decoding apparatus, the method comprising:
 deriving inter prediction samples based on an inter prediction for a current block;   deriving intra prediction samples based on an intra prediction for the current block; and   deriving a prediction block for the current block based on a weighted sum derived by applying weights to the inter prediction samples and the intra prediction samples.   
     
     
         2 . The image decoding method of  claim 1 , wherein the intra prediction samples are derived based on an intra prediction mode, and
 wherein the intra prediction mode is one of a DC mode, a planar mode, a vertical mode and a horizontal mode.   
     
     
         3 . The image decoding method of  claim 1 , wherein the intra prediction samples are derived based on a vertical mode, and
 wherein a first weight of a first intra prediction sample is used for a first distance between an above reference sample of the current block and the first intra prediction sample,   wherein a second weight of a second intra prediction sample is used for a second distance between the above reference sample and the second intra prediction sample,   wherein based on the second distance being greater than the first distance, the first weight is greater than the second weight.   
     
     
         4 . The image decoding method of  claim 3 , wherein a third weight of a first inter prediction sample is used for the first distance,
 wherein a fourth weight of a second inter prediction sample is used for the second distance,   wherein based on the second distance being greater than the first distance, the third weight is smaller than the fourth weight.   
     
     
         5 . The image decoding method of  claim 1 , wherein the intra prediction samples are derived based on a horizontal mode, and
 wherein a first weight of a first intra prediction sample is used for a first distance between a left reference sample of the current block and the first intra prediction sample,   wherein a second weight of a second intra prediction sample is used for a second distance between the left reference sample and the second intra prediction sample,   wherein based on the second distance being greater than the first distance, the first weight is greater than the second weight.   
     
     
         6 . The image decoding method of  claim 5 , wherein a third weight of a first inter prediction sample is used for the first distance,
 wherein a fourth weight of a second inter prediction sample is used for the second distance,
 wherein based on the second distance being greater than the first distance, the third weight is smaller than the fourth weight. 
   
     
     
         7 . The image decoding method of  claim 1 , wherein the weights are set based on a size of the current block or an intra prediction mode applied to the current block. 
     
     
         8 . The image decoding method of  claim 1 , wherein the deriving the prediction block for the current block includes applying a weight of ½ to the inter prediction samples and the intra predication samples, respectively. 
     
     
         9 . An image encoding method performed by an image encoding apparatus, the method comprising:
 deriving inter prediction samples based on an inter prediction for a current block;   deriving intra prediction samples based on an intra prediction for the current block;   deriving a prediction block for the current block based on a weighted sum derived by applying weights to the inter prediction samples and the intra prediction samples; and.   encoding image information comprising prediction mode information for the current block.   
     
     
         10 . The image encoding method of  claim 9 , wherein the intra prediction samples are derived based on an intra prediction mode, and
 wherein the intra prediction mode is one of a DC mode, a planar mode, a vertical mode and a horizontal mode.   
     
     
         11 . The image encoding method of  claim 9 , wherein the intra prediction samples are derived based on a vertical mode, and
 wherein a first weight of a first intra prediction sample is used for a first distance between an above reference sample of the current block and the first intra prediction sample,   wherein a second weight of a second intra prediction sample is used for a second distance between the above reference sample and the second intra prediction sample,   wherein based on the second distance being greater than the first distance, the first weight is greater than the second weight.   
     
     
         12 . The image encoding method of  claim 11 , wherein a third weight of a first inter prediction sample is used for the first distance,
 wherein a fourth weight of a second inter prediction sample is used for the second distance,   wherein based on the second distance being greater than the first distance, the third weight is smaller than the fourth weight.   
     
     
         13 . The image encoding method of  claim 9 , wherein the intra prediction samples are derived based on a horizontal mode, and
 wherein a first weight of a first intra prediction sample is used for a first distance between a left reference sample of the current block and the first intra prediction sample,   wherein a second weight of a second intra prediction sample is used for a second distance between the left reference sample and the second intra prediction sample,   wherein based on the second distance being greater than the first distance, the first weight is greater than the second weight.   
     
     
         14 . The image encoding method of  claim 13 , wherein a third weight of a first inter prediction sample is used for the first distance,
 wherein a fourth weight of a second inter prediction sample is used for the second distance,   wherein based on the second distance being greater than the first distance, the third weight is smaller than the fourth weight.   
     
     
         15 . The image encoding method of  claim 9 , wherein the weights are set based on a size of the current block or an intra prediction mode applied to the current block. 
     
     
         16 . The image encoding method of  claim 9 , wherein the deriving the prediction block for the current block includes applying a weight of ½ to the inter prediction samples and the intra predication samples, respectively. 
     
     
         17 . A transmission method for image data, the method comprising:
 obtaining a bitstream for the image data, wherein the bitstream is generated based on deriving inter prediction samples based on an inter prediction for a current block; deriving intra prediction samples based on an intra prediction for the current block; deriving a prediction block for the current block based on a weighted sum derived by applying weights to the inter prediction samples and the intra prediction samples and encoding image information comprising prediction mode information; and   transmitting the image data comprising the bitstream.   
     
     
         18 . The transmission method of  claim 17 , wherein the intra prediction samples are derived based on an intra prediction mode, and
 wherein the intra prediction mode is one of a DC mode, a planar mode, a vertical mode and a horizontal mode.   
     
     
         19 . The transmission method of  claim 17 , wherein the intra prediction samples are derived based on a vertical mode, and
 wherein a first weight of a first intra prediction sample is used for a first distance between an above reference sample of the current block and the first intra prediction sample,   wherein a second weight of a second intra prediction sample is used for a second distance between the above reference sample and the second intra prediction sample,   wherein based on the second distance being greater than the first distance, the first weight is greater than the second weight.   
     
     
         20 . The transmission method of  claim 17 , wherein the intra prediction samples are derived based on a horizontal mode, and
 wherein a first weight of a first intra prediction sample is used for a first distance between a left reference sample of the current block and the first intra prediction sample,   wherein a second weight of a second intra prediction sample is used for a second distance between the left reference sample and the second intra prediction sample,   wherein based on the second distance being greater than the first distance, the first weight is greater than the second weight.