Patent ID: 7369705

Claim:
An image data compression device for compressing image data, the image data compression device comprising: an image data processing section which includes a quantization section which quantizes image data by a quantization step which changes based on a quantization parameter; a FIFO buffer section in which quantized data for at least N frames (N is an integer larger than one) quantized by the quantization section is buffered; an encoded data generation section which reads the quantized data from the FIFO buffer section asynchronously from writing into the FIFO buffer section, and generates encoded data by encoding the quantized data; a rate control section which calculates the quantization parameter by using a data size of the encoded data, and controls a data size of encoded data to be processed by changing the quantization step of the quantization section; and a frame skip section which performs skip processing of causing the image data processing section to skip processing of image data in a frame processed by the image data processing section or image data in a frame subsequent to the processed frame, wherein the rate control section calculates the quantization parameter by using an average data size obtained by averaging the data size of the encoded data for N frames before a frame of the image data quantized by the quantization section, and wherein the frame skip section performs the skip processing when a frame in which the quantization parameter calculated for each frame is greater than a skip threshold continues a number of times equal to or greater than a number of times set as a skip continuous number threshold.