Patent ID: 8253817
Filing Date: 2012-08-28
Classification: H04N

Abstract:
1. An image compression method compressing data of an image data group, comprising: obtaining a motion vector between the sets of image data for a plurality of positions on an image; determining whether variation of the motion vector on the image (hereinafter, called spatial variation) is large or small; selecting an image area A, which is determined to have the large spatial variation of the motion vector, from the image data to be compressed, and subjecting the selected image area A to intra-frame compression; selecting an image area B, which is determined to have the small spatial variation of the motion vector, from the image data to be compressed, and subjecting the selected image area B to inter-frame prediction differential compression; wherein obtaining the motion vector includes: terminating the block sectionalization in the lower hierarchy under a termination condition that a motion vector variation of the block between the hierarchies is stabilized within a predetermined acceptable amount; selecting a block with a final section size being smaller than a block size of a minimum unit to carry out a motion vector detection, setting the block being selected as the image area A, and subjecting the image area A to intra-frame compression; and selecting a block with a final section size being larger than the block size of the minimum unit to carry out the motion vector detection, setting the block being selected as the image area B, and subjecting the image area B to inter-frame prediction differential compression, wherein the determination section terminates further sectionalization of the block before a hierarchical block section size becomes smaller than the block size of the minimum unit to carry out the motion vector detection, the intra-frame compression section assumes that a block in which block sectionalization being terminated without satisfying the termination condition is the block with the final section size being smaller than the block size of the minimum unit to carry out the motion vector detection, and subjects the block to intra-frame compression, and the inter-frame compression section subjects the block in which the block sectionalization being terminated by satisfying the termination condition to inter-frame prediction differential compression.