JPS6441377A - Area identification method for picture processing unit - Google Patents

Abstract

PURPOSE:To obtain a picture with high picture quality by detecting an edge component from a kind of signal formed from plural color signals, comparing the detected result with a threshold value corresponding to a hue signal obtained from a hue identification means so as to identify a halftone region and a binary picture region. CONSTITUTION:A binary picture filter processing circuit 7 applies high frequency emphasis processing to correct the deterioration of the edge component such as a character due to the optical system. A binarizing circuit 8 uses fixed threshold values B1-B3 so as to binarize each of picture data B, G, R only when hue signals b1, g1, r1 from a hue identification circuit 10 are set and outputs the picture data R, G, B as they are when the signals b1, g1, r1 are reset. That is, a contrast data is compared with the fixed threshold value B to apply data conversion. Then the halftone picture data from the obtained halftone picture filter processing circuit 6 and the binary picture data from the binarizing circuit 8 are switched by a selection circuit 9 by using a discrimination signal from the area identification circuit 17 and the result is outputted to the post-stage processing circuit. Thus, even an original having a halftone area and a binary picture area existence in mixture is reproduced with high quality.