Abstract: A picture transmission system for compressing picture information to transmit compressed picture information is provided. The picture transmission system includes, on the transmitter side, circuitry for realizing scene change detecting function. This circuitry comprises a buffer memory for storing picture signal of one frame to output it in order of luminance signal Y, and chrominance signals C.sub.B, C.sub.

Abstract: A picture transmission system used in a picture remote surveillance system or a visual telephone, etc. is provided. This picture transmission system includes, on the transmitter side, an A-D converter for converting an analog video input signal into a digital picture signal, a moving picture converting section for converting the picture signal into a reduced moving picture, a video encoder for compression-encoding the reduced moving picture by the hybrid coding system. In this picture transmission system, on the transmitter side, a switch operative in response to a signal from the receiver side is provided between the A-D converter and the moving picture converting section, and a still picture converting section is inserted between the switch and the video encoder. A picture signal outputted from the A-D converter is permitted to be selectively inputted to either the moving picture converting section or the still picture converting section.