JPS5617486A - Thinning-out unit - Google Patents

Abstract

PURPOSE:To thin out a binary pattern without distortion even at the intersection of a character part by forming an internal pattern at each point of an original pattern from upper and lower, and right and lower areas and areas at respective points and then by forming a frame pattern of the original pattern and internal pattern. CONSTITUTION:Input pattern quantization part 1 scans an input pattern in a two- dimensional array shape and binary-codes and outputs shade at each pattern position to thinning-out part 2. Thinning-out part 2 deletes bits, one by one, in one run without losing linkages from the circumference of the pattern and continues to thin out the pattern until the line width of the input pattern reaches one or two bits, thereby transmitting the result to final thinning-out part 3. Control part 5 receives control signal 52 for thinning-out part 2 to exercise operation control over quantization part 1 and thinning-out parts 2 and 3 with control signal 52. Through the thinning-out processing of thinning-out part 2, an internal pattern is formed from circumferential areas of each point of the original pattern and this pattern and original pattern are used to form a frame pattern which can not be deleted, so that bit-by-bit delection processing will be carried out under deletion conditions symmetrical vertically and horizontally and obliquely at angles of 45 deg..