Error compensation by a ramp waveform having high signal-to-noise ratio.

摘要

A signal processing circuit for a video recording and reproducing apparatus comprises a ramp inserting circuit (17) for inserting a ramp waveform at periodic intervals into a video signal during recording. The ramp waveform varies linearly as a function of time from the minimum to the maximum level of the video signal. On playback, the inserted ramp is periodically detected from a reproduced video signal by a ramp detector (56A, 56B). The waveform of the detected ramp is corrected to improve its signal-to-noise ratio by an averaging circuit (70, 70') and applied to a transfer circuit (71, 72,73) having a transfer function describing the relationship between the original ramp waveform and the corrected ramp waveform. The waveform of the reproduced video signal is transformed according to the transfer function.