An image information processor for producing a high-quality output image by emphasizing the contour portions of a character, a photograph and others and by preventing the generation of a Moire patterns in a dot region, for preventing an increase in the amount of codes, and for making it unnecessary to set desired binarization processing for each original, is provided. The processor includes a unit for scanning the original to convert each pixel data into an electric signal, a unit for controlling the start of image processing, a filter for carrying out enhancement processing among a plurality of pixels arranged in oblique directions after smoothing processing has been carried out among a plurality of contiguous pixels arranged in scanning and traverse directions, and a unit for carrying out at least one of binarization and binarization capable of realizing pseudo tone expression. According to the above construction of the image information processor, a unit for preventing the generation of a Moire pattern in the dot region of an original and for carrying out contour enhancement for the character/photograph region of the original can be formed of simple hardware capable of performing a high-speed operation, a clear binary output is obtained, and an increase in transmission time is prevented.