IMAGE CODING DEVICE AND METHOD, AND IMAGE DECODING DEVICE AND METHOD

摘要

PROBLEM TO BE SOLVED: To decrease the information content when the same image data are encoded at the same level of picture quality by adding or subtracting the existing range of the original pixel value to and from an estimation error if the absolute value of the estimation error exceeds the half of the said existing range. SOLUTION: A blocking part 11 divides a 1-frame image of input image signals into a prescribed number of blocks and outputs the pixel data on every divided block to a memory 12 and an adder 13. The memory 12 successively stores the 1-frame preceding image signals of video signals inputted to an image encoder 10. The adder 13 calculates the difference between the pixel value of every block of each frame of video signals received from the part 11 and the value of the 1-frame preceding corresponding pixel that is sent from the memory 12 and then converts the current frame pixel value into the value that is estimated based on the 1-frame preceding image. An encoding part 15 and a quantization part 16 encode the pixel data on the image data corrected at a difference correction part 14 in every block and then integrate the data on every block which are encoded at a framing part 17 to generate and output the encoding data on each frame.