JPS6037952B

PURPOSE:To make binary for the video signal read out from the video buffer, by obtaining the rate of line width indication through the division of number of black points with the number of surrounding, comparing the rate with the reference rate, and obtaining the slice level. CONSTITUTION:The multi-value video signal is stored in the video buffer 1, and the slice circuits 2-0...2-3 binarizes the video signal from the buffer 1. In this case, as to a plurality of binary video signals formed with slicing by different slice level, the number of black points at the black point circuits 3-0...3-3 is respectively divided 5-0...5-3 with the number of surrounding of the surrounding point count circuits 4-0...4-3 to obtain the line width indicating rate. This is compared 6 with the reference rate to determine the slice level at the slice circuit 7. Thus, the multi- value video signal read out from the buffer 1 can be binarized.