Patent ID: 8325802

Claim:
An image data compression device to compress image data of a motion image, the image data compression device comprising: a motion estimation part that receives input image data of a present frame of the motion image and that generates motion vector data based on a difference between the input image data of the present frame and previous image data of a previous frame of the motion image; a quantization part that generates quantized image data, based on the motion vector, with a quantization step that varies based on a quantization parameter; a coded data formation part that generates coded data by encoding the quantized image data; a FIFO buffer part buffering the quantized image data generated by the quantization part; a rate control part that controls a data size of the coded data by changing the quantization parameter of the quantization part, the rate control part calculating a predicted data size of the coded data based on a number of accesses being made to the FIFO buffer part, calculating the quantization parameter of the quantization part based on the predicted data size, and controlling a bit rate of the image data compression device based on the predicted data size; the motion estimation part halting the generation of the motion vector data when a predetermined bit rate cannot be realized.