A digital image processing system for slow scan television

This paper describes a low cost, but powerful, digital image processing system. Although general purpose, it was designed for experimentation with amateur radio slow scan television (SSTV). The project involved conceptualizing, designing, building, programming, and operating the complete integrated system. The image format is the SSTV standard: 128 picture elements (pixels) per line, 128 lines, 4 bits per pixel. The IEEE Standard 696 (S-100) microcomputer bus was used for system interconnect to provide flexibility and expandability. Several microcomputer boards were purchased, and two image interface boards were designed and built by the author. One image interface board provides for transmitting and receiving images at SSTV rates. The other board can accept a single frame image from a standard TV camera, store it in memory, and continuously output an image from memory to a video monitor. Any image in memory can be analyzed or modified, pixel by pixel, by programs running on the system\u27s Z80 micro processor. Simple keyboard commands can initiate many digital image processing programs that were written for the system, including the powerful point processing and two dimensional convolution functions