Patent ID: 8340454

Claim:
An information processing device comprising: block level information obtaining means: to detect block levels, each of the block levels being detected based on differences in pixel values between a predetermined pixel of an image and nearby pixels near to the predetermined pixel, and to obtain distribution information by accumulating said block levels in a predetermined direction; short cycle measuring means to: measure, from said distribution information, short cycle information, which includes the distribution information for each phase in a plurality of predetermined short cycles corresponding to a plurality of block sizes including an integer pixel count, and obtain a distribution for each interval between peak values from said distribution information, as occurrence frequency; and determining means: to determine one of the plurality of predetermined short cycles whose phase distribution takes a maximum value, and to set a block size corresponding to the short cycle information of the identified short cycle as an image block size of said image, wherein said determining means is configured to: divide the short cycle information corresponding to the block sizes of said integer pixel count into a plurality of segments, obtain the position for the maximum value to take for each segment, determine the block border position corresponding to the block size below the decimal, based on the positional relation of said plurality of maximum values, determine the block size wherein the distribution count is the maximum count of said short cycle information, and corresponds to a cycle having a high occurrence frequency, as said image block size, and determine the phase to take the maximum value in said short cycle information as the block border position, wherein said determinations are performed based on the distribution count of said short cycle information, and occurrence frequency corresponding to the interval between peak values.