Patent ID: 8248493

Claim:
A video signal processing apparatus, comprising: a section determination unit which detects a non-equidistant section having different intervals between a plurality of sample points set for a range from a minimum signal level to a maximum signal level of a video signal to be inputted; a correction level holding unit which holds a signal level of a video signal after correction for each sample point as a correction level; and an interpolation computation unit which obtains a signal level of the video signal after correction corresponding to the signal level of the inputted video signal by executing cubic interpolation computation with reference to the correction level held by the correction level holding unit, wherein, with a border point defined as a sample point to be a border between a first section located on a lower signal level side and having intervals of X (X>0) between sample points, and a second section located on a higher signal level side and having intervals of Y (Y>0, X.noteq.Y) between sample points, the signal level of the video signal after correction is obtained by use of the correction level of a sample point added or designated so as to form at least one of the second section on the lower signal level side and the first section on the higher signal level side of the border point, in a case where X≧nY (n is an integer larger than 1), a sample point is added on the lower signal level side of the border point and at a position having a distance Y from the border point, and another sample point is added on the higher signal level side of the border point and at a position having a distance X from the border point, and in a case where nX≦Y (n is an integer larger than 1), a sample point is added on the higher signal level side of the border point and at a position having a distance X from the border point, and another sample point is added on the lower signal level side of the border point and at a position having a distance Y from the border point.