| 摘要 |
PURPOSE:To increase a dynamic range and to facilitate assuredly the binary coding with a simple circuit constitution, by amplifying the picture signal by an amount equivalent at least to the ground density after removing the ground density component out of the picture signal. CONSTITUTION:A picture reader 1 converts the picture information obtained from an original picture into electric signals and then delivers them. This picture signal is applied to a ground information removing circuit 4 after amplification 2. The circuit 4 removes the ground density component detected by a ground information detecting circuit 3 out of the picture signal. The picture signal free from the ground density component is amplified by an amount equivalent at least to the ground density component through an amplifier 5 having its variable amplification degree on the basis of the output of the circuit 3. This amplified signal is binary coded by a binary coding circuit 6 to be stored temporarily in a memory 7 and then recorded by a picture recorder. Thus the picture signal can be binary coded easily and assuredly, and therefore a recorded picture having a high contrast is obtained. |
