Television receiver that provides gradation correction using a CPU

A television receiver comprising an information extracting circuit for extracting information from a format or content of an input video signal, a video signal processing circuit for processing this video signal by a program or data, a memory for storing the program and data, a CPU for controlling, operating or driving these elements, and a display device for displaying an image. The video signal processing circuit can, under the control of the CPU, decode the signal, correct or set the picture quality such as gradation and sharpness, or adaptively process an on-screen display based on the input video signal. The television receiver is also able to adaptively extend the functions of the television receiver corresponding to various signal formats.