FACSIMILE-BASED VIDEO COMPRESSION METHOD AND SYSTEM

摘要

A method and system (10) for compressing and decompressing video image data in real time employs thresholding and facsimile-based encoding to eliminate the need for computationally intense two-dimensional transform-based compression techniques. The method operates first by forming a difference frame which contains only information pertaining to the difference between a current video image frame and a computed approximation of the video image frame. The difference frame is fed to a thresholder (32) which categorizes each pixel in the frame as being either in a first set having intensities above or at a preset threshold, or a second set having intensities below a preset threshold. A facsimile-based compression algorithm in an encoder (44) is then employed to encode the first set of above or at threshold pixel locations. To compress the intensity data for each above or at threshold pixel, a quantizer (40) and a lossless encoder (50) are preferably employed.