Patent ID: 7130472

Claim:
An image distribution apparatus that divides image data for a single frame into a plurality of blocks, orthogonally transforms the blocks and calculates transformation coefficients, quantizes the calculated transformation coefficients, codes the quantized transformation coefficients, and distributes the coded image data to an external apparatus, comprising: a) an acquiring unit for acquiring the quantized transformation coefficients; b) a storage unit for storing the quantized transformation coefficients acquired by said acquiring unit; c) a calculation unit for calculating differences between quantized transformation coefficients of a first frame stored in said acquiring unit and quantized transformation coefficients of a second frame stored in said acquiring unit; d) a changing block count unit for counting the number of blocks whose difference values calculated by said calculation unit are equal to or greater than a predetermined value, as changing blocks of the first frame; and e) a detection unit for detecting a changing frame by determining that the first frame has changed when the number of blocks counted by the changing block count unit is equal to or greater than a predetermined value.