| 摘要 |
PURPOSE:To express area blocks of a color original such as a map to be easily observed by printing an image in a mono-tone based on image data converted from original image data so that a density histogram obtained from the original image data forms plural separated and flat areas. CONSTITUTION:When the map mode is selected, a CCD section 51a of an image data input section 51 reads an image and a histogram(Hg) processing section 51b generates a density Hg. Furthermore, image data are stored in a memory 61 via an error spread processing section 51c. Then the image data are subject to multi-value processing by a multi-value processing section 2, subject to density conversion by a density conversion section 52d, an image process section 52f detects a peak and a notch of the Hg at the input to make separation and flat processing. The image data are subject to 4-value processing again by an error spread processing section 52g and a compression processing section 52g, compressed by the compression processing section 52h, the result is stored in the memory 61 and the data are read by an image data output section 53 and printed out. Thus, the area block of a color original is printed out to be easily observed. |
