Abstract: An image processing method and apparatus for converting image data for use in a color CRT and an image processing device each having a different color reproducible range, for example, a color printer. Color component data of color image data corresponding to a most parts of a color reproducible range of the color printer having a color reproducible region which is narrower than that of the color CTR is not converted. The hue and the brightness of color component data of color image data exceeding the color reproducible range of the color printer are not substantially converted but only chromaticness is converted. A part deviated from the color reproducible range can be approximated to the outer periphery of the reproducible range. Furthermore, the most part of the color reproducible range is correctly color-reproduced and the color image is converted so as to make a portion of the same to be a compressed space of an all color space.

Abstract: A method of discriminating pictures, wherein a picture is binary-coded. The variation in the number of foreground pixels constituting foreground pixel regions within a discrimination unit area is determined. Alternatively the variation in the distance between said foreground pixel regions is determined. It is then determined by a known relationship whether the discrimination unit area is of a dot gradation picture or not. If the picture is not a dot gradation picture, the rate of background is measured to determine whether the above discrimination unit area is of a line picture or of a continuous tone picture.