IMAGE READER

PURPOSE:To realize the extraction processing of a character and a symbol. etc., realized by a digital filter in a conventional system with simple and inexpen sive constitution. CONSTITUTION:Light projected by a light source 12 and reflected from almost the same position on an original 11 is converged by an optical system 13, and is image-formed on a one-dimensional image pickup element 16 with high resolution consisting of a fine optical detector, and one-dimensional image pickup devices 15, 17 with low resolution consisting of optical detectors with comparatively large areas arranged at both sides of the detector 16. Output 18, 20 from the one-dimensional image pickup elements 15, 17 with low resolution are added. and after that, the high frequency component is cut, and it goes to data representing the mean brightness of the peripheral area of a picture element targeted to read. Thence, difference between the data and the data representing the brightness of the picture element targeted to read itself outputted from the one-dimensional image pickup element 17 with high resolution is found, and the change part of the brightness of the image is emphasized and outputted based on the difference, thereby, the character and the symbol, etc., can be accurately extracted.