A CMOS facsimile video signal processor

A CMOS image scanning signal processor which can be used for CCITT Group-4 facsimile has been developed. To obtain high-speed processing (5 MHz) and high-precision shading distortion correction (up to 70%), hybrid architecture of digital and analog techniques and parameter setting by software are combined. Image sensor and printer interfaces and a digital processor which can do linear zooming and data format conversion are built into a chip. The 6.5/spl times/7.8-mm chip is fabricated using 2.5 /spl mu/m CMOS technology and contains 25000 transistors.