| 摘要 |
PURPOSE:To binarize an edge of a contrast pattern and a minute pattern accurately, by binarizing an original picture signal at different three levels and obtaining a binary signal of each picture signal, taking a binary signal of an intermediate level as a reference. CONSTITUTION:Analog picture signals are binarized at three binarizing circuits as high, intermediate and low level, and signals H, M and L are outputted. The signals are applied to serial shift registers 100, 102 and 105 in 7-bit, and a picture element in 7 7-bit is cut out especially with the signal M and inputted to an AND circuit 110 and also to an AND circuit 111 via an inverter. The outputs of the said two AND circuits are ANDed and ORed with the three binarized signals of a center picture element in a cutout section W at an NOR gate 112, AND gates 113-115, and an OR gate 116, to obtain the final binarized picture signal. |
