Patent ID: 7260275

Claim:
An image processing device for forming a composite image by superimposing an overlay image on a base image, said image processing device comprising: a fixed length data forming section for forming fixed length compressed data of the base image and fixed length compressed data of the overlay image by dividing data of the base image and data of the overlay image respectively into a plurality of blocks and by encoding a statistical parameter of each block, including a gray level representing the block, and quantization levels of respective pixels in the block; and an image composing section for forming fixed length compressed data of a composite image by, while checking the fixed length compressed data of the base image and the fixed length compressed data of the overlay image in a block-by-block manner, taking in the fixed length compressed data of the base image if the gray level of the block of the overlay image is 0 and taking in the fixed length compressed data of the overlay image if the gray level of the block of the overlay image is not 0.