X-ray image compression using run length coding

The recent availability of a special-purpose IC implementing the standard CCITT run length coder/decoder has made it possible for distortion free image compression to be done economically and quickly with a personal computer plug-in circuit card. Although the code table implemented is designed for bit-mapped document images at one bit per pixel, an experiment has been undertaken to investigate its role in compressing multiple bit per pixel images such as radiographs. Representative x-ray images of various body parts are processed; the average compression ratio and standard deviation is 2.37 and 0.28, respectively, for CCITT group 4 compression, and 2.21 and 0.29, for CCITT group 3 compression.