| 摘要 |
PURPOSE:To improve transmission efficiency and to make the system suitable for privacy communication by comparing pictures in the unit of frames or fields and processing the signal so that only a difference part of the picture is sent as the picture signal of the frame or field. CONSTITUTION:When a 1st frame original signal (a0+b0) from a signal source 1 is AD-converted and inputted to a CPU 4, since no picture exists in the preceding frame and no picture data exists in a frame memory 3, the digital original signal (a0+b0) is written in the frame memory 3 and outputted. When a 2nd frame original signal (a0+b1) is inputted to the CPU 4, a read instruction is outputted from the CPU 4 to the frame memory 3 in which the picture data (a0+b0) is written and read to the CPU 4. Since the characters 'b0' and 'b1' differ from the picture data (a0+b0) and the original signal (a0+b1), the picture data (b1) is outputted as the comparison output of the CPU 4. |
