Method and device for encoding and decoding image

Abstract

A video encoding method according to an embodiment of the present invention includes generating header information that includes information about resolutions of motion vectors of respective blocks, determined based on motion prediction for a unit image. Here, the header information includes flag information indicating whether resolutions of all motion vectors included in the unit image are integer-pixel resolutions. Further, a video decoding method according to another embodiment of the present invention includes extracting information about resolutions of motion vectors of each unit image from header information included in a target bitstream to be decoded; and a decoding unit for decoding the unit image based on the resolution information. Here, the header information includes flag information indicating whether resolutions of all motion vectors included in the unit image are integer-pixel resolutions.

1 . A video encoding apparatus, comprising:
 a bitstream generation unit for including information about resolutions of motion vectors of respective blocks, determined based on motion prediction for a unit image, in header information of a bitstream,   wherein the header information includes flag information indicating whether resolutions of all motion vectors included in the unit image are integer-pixel resolutions.   
     
     
         2 . The video encoding apparatus of  claim 1 , further comprising:
 a motion prediction unit for performing motion prediction on the unit image on a per-block basis; and   a motion vector encoding unit for encoding motion vectors determined for respective blocks in a motion prediction procedure,   wherein the motion vector encoding unit is configured to, when a resolution of a motion vector of a target block to be encoded is different from a resolution of a motion vector of a neighboring block, scale the motion vector of the neighboring block with respect to the resolution of the motion vector of the target block to be encoded.   
     
     
         3 . The video encoding apparatus of  claim 2 , wherein the motion vector encoding unit is configured to, when the resolution of the motion vector of the target block to be encoded is an integer-pixel resolution, and the resolution of the motion vector of the neighboring block is a sub-pixel resolution, map the motion vector of the neighboring block to a value corresponding to a quotient for values in a sub-pixel unit of the motion vector of the neighboring block. 
     
     
         4 . The video encoding apparatus of  claim 2 , wherein the motion vector encoding unit is configured to, when the resolution of the motion vector of the target block to be encoded is a sub-pixel resolution and the resolution of the motion vector of the neighboring block is an integer-pixel resolution, map the motion vector of the neighboring block to a value obtained by scaling values in an integer unit of the motion vector of the neighboring block to values in a sub-pixel unit. 
     
     
         5 . The video encoding apparatus of  claim 1 , wherein the header information is configured to, when the unit image includes regions, each composed of blocks, for which resolutions of motion vectors are not integer-pixel resolutions, include information about a number and positions of the regions. 
     
     
         6 . The video encoding apparatus of  claim 5 , wherein the information about the positions of the regions includes index information of a start block and index information of an end block of the blocks, for which resolutions of the motion vectors are not integer-pixel resolutions. 
     
     
         7 . The video encoding apparatus of  claim 1 , wherein the header information is configured to, when the unit image includes regions, each composed of blocks, for which resolutions of motion vectors are integer-pixel resolutions, include information about a number and positions of the regions. 
     
     
         8 . The video encoding apparatus of  claim 7 , wherein the information about the positions of the regions includes index information of a start block and index information of an end block of the blocks, for which resolutions of the motion vectors are integer-pixel resolutions. 
     
     
         9 . A video decoding apparatus, comprising:
 a parsing unit for extracting information about resolutions of motion vectors of each unit image from header information included in a target bitstream to be decoded; and   a decoding unit for decoding the unit image based on the resolution information,   wherein the header information includes flag information indicating whether resolutions of all motion vectors included in the unit image are integer-pixel resolutions.   
     
     
         10 . The video decoding apparatus of  claim 9 , wherein the decoding unit performs decoding on the corresponding unit image on a per-integer-pixel basis based on the flag information indicating that resolutions of all motion vectors included in the unit image are integer-pixel resolutions. 
     
     
         11 . The video decoding apparatus of  claim 9 , wherein the decoding unit reconstructs a target block based on a difference signal between a predicted block and an original block and a motion vector,
 wherein the decoding unit is configured to, when a resolution of a motion vector of a target block to be decoded is different from a resolution of a motion vector of a neighboring block, scale the motion vector of the neighboring block with respect to the resolution of the motion vector of the target block to be decoded.   
     
     
         12 . The video decoding apparatus of  claim 11 , wherein the decoding unit is configured to, when the resolution of the motion vector of the target block to be decoded is an integer-pixel resolution, and the resolution of the motion vector of the neighboring block is a sub-pixel resolution, map the motion vector of the neighboring block to a value corresponding to a quotient for values in a sub-pixel unit of the motion vector of the neighboring block. 
     
     
         13 . The video decoding apparatus of  claim 11 , wherein the decoding unit is configured to, when the resolution of the motion vector of the target block to be decoded is a sub-pixel resolution and the resolution of the motion vector of the neighboring block is an integer-pixel resolution, map the motion vector of the neighboring block to a value obtained by scaling values in an integer unit of the motion vector of the neighboring block to values in a sub-pixel unit. 
     
     
         14 . The video decoding apparatus of  claim 9 , wherein the header information is configured to, when the unit image includes regions, each composed of blocks, for which resolutions of motion vectors are not integer-pixel resolutions, include information about a number and positions of the regions. 
     
     
         15 . The video decoding apparatus of  claim 14 , wherein the information about the positions of the regions includes index information of a start block and index information of an end block of the blocks, for which resolutions of the motion vectors are not integer-pixel resolutions. 
     
     
         16 . The video decoding apparatus of  claim 14 , wherein the decoding unit performs decoding on regions, other than a region composed of blocks that are not integer-pixel units, in the corresponding input image on a per-integer-pixel basis, and performs decoding on the region composed of the blocks that are not integer-pixel units, depending on resolution information of motion vectors of respective blocks for the region. 
     
     
         17 . The video decoding apparatus of  claim 9 , wherein the header information is configured to, when the unit image includes regions, each composed of blocks, for which resolutions of motion vectors are integer-pixel resolutions, include information about a number and positions of the regions. 
     
     
         18 . The video decoding apparatus of  claim 17 , wherein the information about the positions of the regions includes index information of a start block and index information of an end block of the blocks, for which resolutions of the motion vectors are integer-pixel resolutions. 
     
     
         19 . The video decoding apparatus of  claim 17 , wherein the decoding unit performs decoding on a region composed of blocks that are integer-pixel units on a per-integer-pixel basis, and performs decoding on regions other than the region composed of blocks that are integer-pixel units depending on resolution information of motion vectors of respective blocks. 
     
     
         20 . The video decoding apparatus of  claim 15 , wherein the decoding unit calculates coordinate values of an upper-left vertex of the start block and coordinate values of a lower-right vertex of the end block, based on the index information of the start block and the index information of the end block.