Abstract: Apparatus for generating at least a selected area in a picture is disclosed herein. The picture and the selected area are displayed on a video display means, and the user can optionally adjust the position and size of the selected area. The apparatus including the following devices. A first converting device that is used to generate a digital signal and a pointer defining signal according to a computer video signal. The picture is transferred from the computer video signal, and the selected area is defined in the pointer defining signal. A first adapting device that is utilized to adapt the format of the computer video signal to suit a digital display format corresponding to the pointer defining signal. A storage device determines said display timing of all the pixels of the picture. A pointer generating device generates a plurality of edge of the selected area according to the pointer defining signal.