Abstract: A block judgment section judges whether a subject block including a plurality of subject pixels is a white block, a black character block or a graphic/color block, on the basis of the frequency of white subject pixels and the density distribution of grey subject pixels. A macro-correction section corrects a judgment value of a character block to that of a graphic block, or vice versa on the basis of a first judgment whether there exists a graphic area larger than a predetermined size in the blocks surrounding the subject block, and a second judgment on the ratio between character blocks and graphic blocks in the blocks directly adjoining the subject block. The macro-corrected judgment value of the subject block is used to select image data of a development color or colors required for reproducing the subject block.

Abstract: A color image recognition apparatus capable of judging whether an original is monochromatic or color comprises an image reader for rapidly scanning the original to develop image data and a color display coordinate system for converting the image data to luminance data and color difference data. A pixel color judging unit judges the color of each pixel based upon the luminance data and the color difference data, and a block color judging unit compares the number of color pixels with the number of black pixels contained in each of the plurality of blocks of pixels. An original color judging unit then counts the number of color blocks in the original to judge the color of the original.

Abstract: An image quality control system for an image processing system for producing an image of high quality by removing noise and mesh-dot components from image input signals representing a scanned original image, the image quality control system comprises a low-pass smoothing filter adapted for removing from image input signals representing a halftone image substantially all of any mesh-dot component, for smoothing the image input signals representing the halftone image, and for producing smoothed output signals representing the smoothed image input signals, a smoothing modulation table for modulating the smoothed output signals of the smoothing filter to produce modulated smoothed output signals, a bandpass edge detect filter for detecting edge component signals of the image input signals, the edge component signals comprising a high frequency component of the image input signals, the edge detect filter producing edge output signals, an edge emphasis modulation table for modulating the edge output signals to prod