Image processing device and image processing method

An image processing device comprising:

• an estimating module configured to estimate boundaries of blocks in an input image, the blocks being utilized as units of in-frame transform when the input image was coded;
• a dividing module configured to generate a plurality of sections having boundaries different from the block boundaries estimated by the estimating module;
• a characteristic value calculating module configured to calculate a characteristic value of a subject pixel group having constituent pixels including a pixel in one of the sections and at least one pixel that is adjacent to the pixel by calculating:
• (a) a degree of pixel value dispersion between the constituent pixels of the subject pixel group if all the constituent pixels belong to the same block;
• and
• (b) degrees of pixel value dispersions each obtained between each of the constituent pixels of the subject pixel group and a pixel that is adjacent to the constituent pixels and belongs to the same block as the constituent pixels if the constituent pixels belong to two or more distinct blocks;
• a strength value calculating module configured to calculate a strength value indicating strength to control the strength of smoothing between the constituent pixels of the subject pixel group, the strength value being calculated to be a smaller value as the difference increases;
• a smoothing module configured to perform pixel value smoothing between the constituent pixels with strength corresponding to the strength value calculated by the strength value calculating module to obtain output pixel values;
• and
• a combining module configured to combine sets of output pixel values output by the smoothing module for the respective sections into a single frame.

A method for processing image, the method comprising:

• estimating boundaries of blocks in an input image, the blocks being utilized as units of in-frame transform when the input image was coded;
• calculating a characteristic value of a subject pixel group having constituent pixels including a pixel in the frame and at least one pixel that is adjacent to the pixel by calculating:
• (a) a degree of pixel value dispersion between the constituent pixels of the subject pixel group if all the constituent pixels belong to the same block;
• and
• (b) degrees of pixel value dispersions each obtained between each of the constituent pixels of the subject pixel group and a pixel that is adjacent to the constituent pixels and belongs to the same block as the constituent pixels if the constituent pixels belong to two or more distinct blocks;
• calculating, from the characteristic value, a strength value to control the strength of smoothing between the constituent pixels of the subject pixel group;
• and
• performing pixel value smoothing between the constituent pixels of the subject pixel group according to the strength value.