Patent US 6,339,657

An image data coding and/or decoding system according to the present invention has an input terminal for inputting an image data signal, a screen-area determining section for determining the area of the produced screen by analyzing the image data signal, a code amount assigning section for assignment of the screen on the basis of the determined results from the screen-area determining section, and a coding section for coding the image data signal inputted using the control signal from the code amount assigning control section.