| 摘要 |
PURPOSE:To obtain sufficient resolution even in a vertical direction by adding a random number signal, generated at a longer period than the horizontal pitch of picture elements, and a binary-coded signal, preceding by one scanning line, to an analog picture signal. CONSTITUTION:A radom-number waveform signal 4 for generating radom numbers at a longer period than the horizontal pitch of picture elements and a binary-coded picture signal one scanning line before from a line memory 7 are added to an analog picture signal 1, and the resulting signal is compared with a threshold value 3 by a threshold value circuit 5, thereby performing quantization. Then when a picture element right above is quantized into 0 (white), a feedback signal from the line memory 7 varies an analog image input 1 to the positive side, so that the level at which the output is quantized into 1 (black) becomes lower than that when the feedback is not provided. Namely, when the picture element right above is 0, quantization into 1 tends to be performed, reducing deterioration in vertical resolution. Further, the picture element right above having 1 is the same. |
