Image data coding and restoring method and apparatus for coding and restoring the same

摘要

When encoding the continuous image by dividing the respective frames into a plurality of blocks, the image in the block in the present frame is compared with a corresponding image in the block in the same position of the reference frame and the amount of the changes of the predetermined image element within respective blocks it calculated. Only when the amount of change exceeds the predetermined threshold value, the image data of respective blocks is coded. A plurality of threshold values can be adapted and appropriately changed by considering spatially changing pattern of the amount of the change of the image with regard to the reference frame and a refreshing operation.