发明名称 RAMP GENERATION FOR PREVENTING TRANSITIONS WITH INFINITE SHORT RISE TIME IN A VIDEO SCRAMBLING SYSTEM
摘要 A method and apparatus for generating a ramp at cutpoints in a cut and rotate video line scrambling system. The undesirable shortening of the active portion of the video line which typically occurs in cut and rotate scrambling to overcome the problem of abrupt transitions at the cutpoints is eliminated by providing a synthesized ramp between the video amplitude level at the cutpoint and the blanking level at each of the cutpoints. This synthesized ramp is calculated by digital logic in conjunction with a delay line for inserting the ramp at its proper temporal position in the video signal. The ramp approximates a sine2 function and is formed of three consecutive pixels, each pixel having an associated calculated video amplitude.
申请公布号 AU3176993(A) 申请公布日期 1993.06.07
申请号 AU19930031769 申请日期 1992.11.06
申请人 MACROVISION CORPORATION 发明人 K. HEINZ GRIESSHABER
分类号 H04N7/169 主分类号 H04N7/169
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