METHOD FOR LOWERING PICTURE QUALITY OF ILLEGAL COPY OF COLOR PICTURE

摘要

PROBLEM TO BE SOLVED: To prevent illegal copy of a DVD disk by connecting an RGB-NTSC converter between a computer monitor and an RGB output of a device and displaying a recognizable artifact to impair easy visibility by a recorded signal. SOLUTION: The DVD disk is reproduced by a DVD-ROM drive 10 for computer. Data stored on the DVD disk is compressed according to an MPEG standard. A picture distortion artifact is added to a video signal to be outputted from an RGB converter 16 to prevent occurrence of the illegal copy. A YUV component of the video signal is supplied to a digital signal processor(DSP) 18. The video signal to be outputted from the RGB converter 16 is delayed, and during the delay, detail analysis is performed to an area of the picture to be exposed by the YUV component of the video signal by the DSP 18. When a certain area of minimum detail is selected, the picture distortion artifact is generated from a ROM 24 by the DSP 18.