To provide the video signal encoder which can improve transmission efficiency and the picture quality of a video signal to be transmitted by adaptively encoding body and background data in a frame.

This encoder includes a control signal generator 303 which generates a 1st control signal based upon the body data in the frame and a 2nd control signal based upon the background data in the frame, a converting circuit 310 which converts and encodes pixel block data obtained by using one of both the data to generate a set of conversion coefficients, a quantization parameter control circuit 300 which generates a varied quantization parameter according to one of both the control signals, and a quantizer 320 which quantizes the set of conversion coefficients by using the quantization parameter to generate a set of quantization conversion coefficients. Then the set of conversion coefficients for pixel block data in the frame of the video signal is adaptively encoded by being quantized so that the data on the body are finer than the data on the background according to whether the pixel block data belong to the body in the frame or the background, thereby improving the picture quality more with a limited target bit rate.