ENCODING DEVICE AND METHOD, DECODING DEVICE AND METHOD, STORAGE MEDIUM, PRINTER DRIVER AND STORAGE MEDIUM FOR STORING THE SAME

摘要

PROBLEM TO BE SOLVED: To reversibly encode a multi-level image with high compressibility or to efficiently decode this encoded multi-level image. SOLUTION: A printer driver 4 encodes multi-level image data based on print data indicated by a computer application and outputs the encoded multi- level image data to a printer 6 through a port driver 5. In this case, the printer driver 4 generates a code corresponding to the number of values of the preceding pixel which continues, a code corresponding to a difference value with respect to a previous pixel, and a code showing how many pieces of data that continue from the same position in a scan direction in the preceding line are used and outputs those codes.