BINARIZING SYSTEM OF PICTURE IMAGE SIGNALS

摘要

In a binarizing system wherein analog picture image signals produced by scanning a manuscript picture image is quantized and the quantized signals are converted into digital picture image signals which are binarized into signals representing black or white according to a predetermined threshold value, some picture image signals of picture elements on the same main scanning line as a picture element to be corrected and positioned before the picture element to be corrected among the digital picture image signals are selectively extracted, and at least one of the picture image signals whose level becomes a maximum or a minimum is further selected from the extracted picture image signals. The picture image signal thus selected is used as a reference signal showing the nature of tone of the manuscript picture image for subjecting the picture image signal of the picture image to be corrected to a calculation emphasizing the nature of tone of the picture image to be corrected in the manuscript picture image.