Image processing device and image processing method

Abstract

A decision unit decides whether or not a deblocking filter is applied to color difference components of pixels belonging to a line orthogonal to a block boundary in two adjacent blocks adjacent to each other sandwiching the block boundary of the decoded image, by using color difference components of pixels belonging to a line identical to a line used to decide whether or not the deblocking filter is applied to luminance components of the pixels belonging to the line orthogonal to the block boundary. The filtering unit applies the deblocking to the color difference components of the pixels for which it is decided that the deblocking filter is applied. The present technology can be applied to, for example, a case where encoding and decoding of an image are performed.

1 . An image processing device comprising:
 a decoding unit that decodes a bitstream to generate a decoded image;   a decision unit that decides whether or not a deblocking filter is applied to color difference components of pixels belonging to a line orthogonal to a block boundary in two adjacent blocks adjacent to each other sandwiching the block boundary of the decoded image generated by the decoding unit, by using color difference components of pixels belonging to a line identical to a line used to decide whether or not the deblocking filter is applied to luminance components of the pixels belonging to the line orthogonal to the block boundary; and   a filtering unit that applies the deblocking to the color difference components of the pixels for which it is decided by the decision unit that the deblocking filter is applied.   
     
     
         2 . The image processing device according to  claim 1 , wherein
 in a case where a color format of the decoded image is a YUV422 format, the decision unit performs decision by using color difference components of pixels belonging to two horizontal lines located at both ends of a partial vertical block boundary in the adjacent blocks, among horizontal lines orthogonal to the partial vertical block boundary that is a unit of processing when it is decided whether or not the deblocking filter is applied to a vertical block boundary that is a block boundary in a vertical direction.   
     
     
         3 . The image processing device according to  claim 2 , wherein
 a length of the partial vertical block boundary is four pixels, and   the decision unit decides whether or not the deblocking filter is applied to color difference components of pixels belonging to four horizontal lines of from first to fourth horizontal lines orthogonal to the partial vertical block boundary, by using color difference components of pixels belonging to the first and fourth horizontal lines.   
     
     
         4 . The image processing device according to  claim 2 , wherein
 the decision unit decides whether or not the deblocking filter is applied, by using color difference components of pixels belonging to two horizontal lines located at both ends of the partial vertical block boundary in the adjacent blocks and two horizontal lines adjacent to each other at a center of the partial vertical block boundary in the adjacent blocks, among horizontal lines orthogonal to the vertical block boundary that is a block boundary in the vertical direction.   
     
     
         5 . The image processing device according to  claim 4 , wherein
 a length of the vertical block boundary is eight pixels, and   the decision unit decides whether or not the deblocking filter is applied to color difference components of pixels belonging to eight horizontal lines of from first to eighth horizontal lines orthogonal to the vertical block boundary, by using color difference components of pixels belonging to the first, fourth, fifth, and eighth horizontal lines.   
     
     
         6 . The image processing device according to  claim 1 , wherein
 in a case where a color format of the decoded image is a YUV444 format, the decision unit decides whether or not the deblocking filter is applied, by using color difference components of pixels belonging to two horizontal lines located at both ends of a partial vertical block boundary in the adjacent blocks, among horizontal lines orthogonal to the partial vertical block boundary that is a unit of processing when it is decided whether or not the deblocking filter is applied to a vertical block boundary that is a block boundary in a vertical direction.   
     
     
         7 . The image processing device according to  claim 6 , wherein
 the decision unit decides whether or not the deblocking filter is applied, by using color difference components of pixels belonging to two horizontal lines located at both ends of the partial vertical block boundary in the adjacent blocks and two horizontal lines adjacent to each other at a center of the partial vertical block boundary in the adjacent blocks, among horizontal lines orthogonal to the vertical block boundary that is a block boundary in the vertical direction.   
     
     
         8 . The image processing device according to  claim 1 , wherein
 in a case where a color format of the decoded image is a YUV444 format, the decision unit decides whether or not the deblocking filter is applied, by using color difference components of pixels belonging to two vertical lines located at both ends of a partial horizontal block boundary in the adjacent blocks, among vertical lines orthogonal to the partial horizontal block boundary that is a unit of processing when it is decided whether or not the deblocking filter is applied to a horizontal block boundary that is a block boundary in a horizontal direction.   
     
     
         9 . The image processing device according to  claim 8 , wherein
 the decision unit decides whether or not the deblocking filter is applied, by using color difference components of pixels belonging to two vertical lines located at both ends of the partial horizontal block boundary in the adjacent blocks and two vertical lines adjacent to each other at a center of the partial horizontal block boundary in the adjacent blocks, among vertical lines orthogonal to the horizontal block boundary that is a block boundary in the horizontal direction.   
     
     
         10 . An image processing method comprising:
 decoding a bitstream to generate a decoded image;   deciding whether or not a deblocking filter is applied to color difference components of pixels belonging to a line orthogonal to a block boundary in two adjacent blocks adjacent to each other sandwiching the block boundary of the decoded image, by using color difference components of pixels belonging to a line identical to a line used to decide whether or not the deblocking filter is applied to luminance components of the pixels belonging to the line orthogonal to the block boundary; and   applying the deblocking to the color difference components of the pixels for which it is decided that the deblocking filter is applied.   
     
     
         11 . An image processing device comprising:
 a decision unit that decides whether or not a deblocking filter is applied to color difference components of pixels belonging to a line orthogonal to a block boundary in adjacent blocks adjacent to each other sandwiching the block boundary of a locally decoded image locally decoded when an image is encoded, by using color difference components of pixels belonging to a line identical to a line used to decide whether or not the deblocking filter is applied to luminance components of the pixels belonging to the line orthogonal to the block boundary;   a filtering unit that applies the deblocking to the color difference components of the pixels for which it is decided by the decision unit that the deblocking filter is applied, to generate a filter image; and   an encoding unit that encodes the image by using the filter image generated by the filtering unit.   
     
     
         12 . An image processing method comprising:
 deciding whether or not a deblocking filter is applied to color difference components of pixels belonging to a line orthogonal to a block boundary in adjacent blocks adjacent to each other sandwiching the block boundary of a locally decoded image locally decoded when an image is encoded, by using color difference components of pixels belonging to a line identical to a line used to decide whether or not the deblocking filter is applied to luminance components of the pixels belonging to the line orthogonal to the block boundary;   applying the deblocking to the color difference components of the pixels for which it is decided that the deblocking filter is applied, to generate a filter image; and   encoding the image by using the filter image.