Image processing device and method

Abstract

The present disclosure relates to an image processing device and method that enable suppression of an increase in the amount of coding of a quantization matrix. An image processing device of the present disclosure includes an up-conversion unit configured to up-convert a quantization matrix limited to a size less than or equal to a transmission size that is a maximum size allowed for transmission, from the transmission size to a size that is identical to a block size that is a processing unit of quantization or dequantization. The present disclosure is applicable to, for example, an image processing device for processing image data.

1 . An image processing device, comprising:
 a setting unit configured to set a 16×16 quantization matrix corresponding to a 16×16 transform unit by performing a nearest neighbor interpolation process in which each element of the 8×8 quantization matrix is copied as a value for its 3 neighboring elements in a case where the 16×16 transform unit is selected when the image data are to be orthogonal transformed;   a quantization unit configured to quantize transform coefficient data generated by orthogonal transforming the image data in 16×16 transform unit using the 16×16 quantization matrix set by the setting unit to generate quantized data; and   an encoding unit configured to encode the quantized data generated by the quantization unit to generate a bitstream including the 8×8 quantization matrix obtained by thinning out 3 neighboring elements copied with each element of the 8×8 quantization matrix from the 16×16 quantization matrix set by the setting unit.   
     
     
         2 . The image processing device according to  claim 1 , wherein the setting unit sets a 32×32 quantization matrix corresponding to a 32×32 transform unit by performing a nearest neighbor interpolation process in which each element of the 8×8 quantization matrix is copied as a value for its 15 neighboring elements in a case where the 32×32 transform unit is selected when the image data are to be orthogonal transformed;
 the quantization unit quantizes the transform coefficient data generated by the orthogonal transforming the image data in the 32×32 transform unit using the 32×32 quantization matrix set by the setting unit; and 
 the encoding unit generates a bitstream including an 8×8 quantization matrix obtained by thinning out 15 elements from every  4 ×4 elements of the 32×32 quantization matrix set by the setting unit. 
 
     
     
         3 . The image processing device according to  claim 2 , wherein the encoding unit sets the 8×8 quantization matrix obtained by thinning out elements from the 32×32 quantization matrix as a picture parameter set of the bitstream. 
     
     
         4 . The image processing device according to  claim 1 , wherein the encoding unit sets the 8×8 quantization matrix obtained by thinning out elements from the 16×16 quantization matrix as a picture parameter set of the bitstream. 
     
     
         5 . The image processing device according to  claim 1 , further comprising an orthogonal transforming unit configured to orthogonal transform the image data in a 16×16 transform unit to generate the transform coefficient data. 
     
     
         6 . An image processing method, comprising:
 setting a 16×16 quantization matrix corresponding to a 16×16 transform unit by performing a nearest neighbor interpolation process in which each element of the 8×8 quantization matrix is copied as a value for its 3 neighboring elements in a case where the 16×16 transform unit is selected when the image data are to be orthogonal transformed;   quantizing transform coefficient data generated by orthogonal transforming the image data in 16×16 transform unit using the set 16×16 quantization matrix to generate quantized data; and   encoding the generated quantized data to generate a bitstream including the 8×8 quantization matrix obtained by thinning out 3 neighboring elements copied with each element of the 8×8 quantization matrix from the set 16×16 quantization matrix.   
     
     
         7 . The image processing method according to  claim 6 , wherein setting a 32×32 quantization matrix corresponding to a 32×32 transform unit by performing a nearest neighbor interpolation process in which each element of the 8×8 quantization matrix is copied as a value for its 15 neighboring elements in a case where the 32×32 transform unit is selected when the image data are to be orthogonal transformed;
 quantizing the transform coefficient data generated by the orthogonal transforming the image data in the 32×32 transform unit using the set 32×32 quantization matrix; and 
 generating a bitstream including an 8×8 quantization matrix obtained by thinning out 15 elements from every  4 ×4 elements of the set 32×32 quantization matrix. 
 
     
     
         8 . The image processing method according to  claim 7 , wherein the 8×8 quantization matrix obtained by thinning out elements from the 32×32 quantization matrix is set as a picture parameter set of the bitstream. 
     
     
         9 . The image processing method according to  claim 6 , wherein the 8×8 quantization matrix obtained by thinning out elements from the 16×16 quantization matrix is set as a picture parameter set of the bitstream. 
     
     
         10 . The image processing method according to  claim 6 , wherein
 the image data is orthogonal transformed in a 16×16 transform unit to generate the transform coefficient data.