To provide a compression method of dynamic picture information, which can perform compression processing for a data permitting a forecasting code of an image information at a high compression rate and a high speed, as well as helps improvement in image quality, and to provide its system.

A first mode of the present invention performs block dividing of an image in a frame, before an inter-frame compression processing and approximates (replaces) the each split block as a single plane defined by three elements of a pixel in the block. A second mode mutually compares a pixel, in an original image with a pixel in an image extended, after compression to output a difference information on each pixel; and if a pixel element which generates a larger difference than a parameter exists, a smaller block size is applied. A third mode, when making each spatially block-split I block distributed along a time base between each frame, does not insert the I block into a block position in a frame updated due to the occurrence of the difference between the frames with in a specified time period.