FACILITATED COPY-PROTECTION METHOD WHICH ADDS HORIZONTAL AND VERTICAL DISTORTIONS IN IMAGE

摘要

FIELD: protection against pirate copies. SUBSTANCE: according to one invention claim, method involves adding negative falling signal into piece of TV image which is located outside of visible screen area directly before pulses of line or frame synchronization but belongs to active video signal. This signal is treated by VCR or TV set as synchronization signal which cause premature horizontal or vertical reverse movement of scanning beam. According to one claim of invention method involves generation of lattice structure of alternating gray and black regions in right image corner outside of visible screen. This lattice structure causes premature reverse beam scanning in selected lines with subsequent horizontal movement of information from image in these line on TV receiver which displays illegal copy. This significantly decreases image quality. According to one claim of invention method involves generation of gray structure outside of visible screen region. This causes vertical instability of image. According to one claim of invention method involves narrowing of selected line synchronization pulses which alters start of vertical reverse beam scanning. EFFECT: anomalous low amplitude of video signal which is stored onto illegal copy, increased efficiency of protection against illegal copying. 89 cl, 107 dwg