BINARY CODING METHOD OF STILL PICTURE TV SIGNALS

PURPOSE:To obtain a binary coding device enabling picture signals from a television camera to be binary coded with high quality by executing the calculation of the binary coding threshold level using a simple high-speed circuit. CONSTITUTION:Picture signals in the first frame of a television camera 1 are integrated in an integral circuit 9, converted into digital signals by an A/D converter, and stored in gradation picture memory 3. Then after storing integral values of a frame is completed, a digital integral circuit 10 is operated to rewrite the values into digital integral values, which are applied to a bias voltage adjusting circuit 13 through a D/A conversion circuit 11, and a smoothing circuit 12. The digital integral values are almost the same as the average values of neighboring pixel densities, so almost optical binary processing can be performed with setup of a threshold a little to the black level in a picture with a white ground and that a little to the white level in a picture with a black ground.