Compression of binary facsimile images by preprocessing and color shrinking

Algorithms for preprocessing, global modeling and segmentation, local modeling and representation, and binary encoding of facsimile images are proposed, and their performance is examined. Some binary morphological operations that can be used to improve the quality and increase the compressibility of binary images and the modeling of binary images are discussed. The techniques are incorporated into a set of comprehensive encoding schemes, the PCSE codes. Their effectiveness in compressing the International Telegraphy and Telephony Consultative Committee (CCITT) binary images is demonstrated. The PCSE code using preprocessing and color shrinking prior to encoding is shown to outperform the READ code by from 7 to 42% for the standard CCITT test images with a very small change in image quality