Image decoding device and an image encoding device

Abstract

An image decoding device includes an illumination compensation flag derivation section that derives an illumination compensation flag indicating whether illumination compensation is executed and an illumination compensation section ( 3093 ) that generates a predicted image of a target prediction unit using illumination change parameters derived from an image in a neighbor of the target prediction unit on a target image and a reference region image of a reference image corresponding to the target prediction unit in a case where the illumination compensation flag is a value indicating validity. In a case where a prediction unit which is a generation target of the predicted image is in a merge mode, the illumination compensation flag derivation section decodes the illumination compensation flag from coded data.

1 . (canceled) 
     
     
         2 . An image decoding device comprising:
 a processor, and   a memory associated with the processor; wherein   the processor executes instructions stored on the memory to perform:   deriving an illumination compensation flag indicating whether illumination compensation is executed; and   generating a predicted image of a target block by using illumination change parameters derived from pixels in the neighbor of the target block on a target image and pixels in the neighbor of a reference block which corresponds to the target block in a case where the illumination compensation flag is a value indicating that illumination compensation is executed,   wherein the illumination change parameters are derived from a first parameter and a second parameter,   the first parameter is derived from (i) a sum of a products of the pixels in the neighbor of the reference block and the pixels in the neighbor of the target block, and, (ii) a product of a sum of the pixels in the neighbor of the reference block and a sum of the pixels in the neighbor of the target block,   the second parameter is derived from (i) a sum of a square of the pixels in the neighbor of the reference block and (ii) a square of a sum of the pixels in the neighbor of the reference block, and   a same regularization term is added to the first parameter and the second parameter, or, the same regularization term is added to a parameter which are used to derive the first parameter and a parameter which are used to derive the second parameter.   
     
     
         3 . The image decoding device according to  claim 2 ,
 wherein the regularization term is derived from a value which is a right shift of the sum of a square of the pixels in the neighbor of the reference block.   
     
     
         4 . An image encoding device comprising:
 a processor, and   a memory associated with the processor; wherein   the processor executes instructions stored on the memory to perform:   deriving an illumination compensation flag indicating whether illumination compensation is executed; and   generating a predicted image of a target block by using illumination change parameters derived from pixels in the neighbor of the target block on a target image and pixels in the neighbor of a reference block which corresponds to the target block in a case where the illumination compensation flag is a value indicating that illumination compensation is executed,   wherein the illumination change parameters are derived from a first parameter and a second parameter,   the first parameter is derived from (i) a sum of a products of the pixels in the neighbor of the reference block and the pixels in the neighbor of the target block, and, (ii) a product of a sum of the pixels in the neighbor of the reference block and a sum of the pixels in the neighbor of the target block,   the second parameter is derived from (i) a sum of a square of the pixels in the neighbor of the reference block and (ii) a square of a sum of the pixels in the neighbor of the reference block, and   a same regularization term is added to the first parameter and the second parameter, or, the same regularization term is added to a parameter which are used to derive the first parameter and a parameter which are used to derive the second parameter.