METHOD FOR PROTECTING COPYRIGHT OF COMPRESSED INFORMATION SIGNAL, SIGNAL PROCESSING METHOD, RECORDER AND RECORDING AND REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To surely and easily protect a copyright of a compressed information signal without taking a difference from the compression method and a difference from a signal format into account by uncompressing the compressed information signal, converting the uncompressed information signal into a base band signal and detecting copyright protection information. SOLUTION: A switching control signal SW throws a switch circuit 2 to a position R of an input terminal in the case of recording and to a position P of the input terminal in the case of reproduction respectively. Then any compressed digital video signal selected through the switching is fed to a decode section 23. The decode section 23 gives its decode output to a reproduction control section and also to an electronic watermark information detection section (WM detection section) 4. The WM detection section 4 uncompresses the compressed signal and detects copyright protection information of an electronic watermark from a video base band signal. A control section 1 controls a copy permission prohibit control section 12 and a reproduction control section 24 based on a discrimination output of copy control information as the copyright protection information.