Patent ID: 6266088
Filing Date: 2001-07-24
Classification: H04N

Abstract:
An edge crispening circuit comprising:comparator means and level-varying means, wherein a first arithmetic means for calculating a first ratio of a level of an input blue (B) signal to a level of an input green (G) signal;a second arithmetic means for calculating a second ratio of a level of an input red (R) signal to the level of the green (G) signal;a decision means for producing a coefficient, or a weighting factor, used to control a magnitude of an edge crispening signal added to said R, G, and B signals;means for producing a weighted edge crispening signal by multiplying said edge crispening signal by said coefficient and for adding said weighted edge crispening signal to said R, G, and B signals, respectively, andsaid first arithmetic means calculates a coefficient k1 from the level of said B signal and from the level of said G signal and produces said coefficient k1;said second arithmetic means calculates a coefficient k2 from the level of said R signal and from the level of said G signal and produces said coefficient k2;said comparator means compares the coefficients k1 and k2 in terms of magnitude and selects a greater one;said decision means compares the coefficient k1 or k2 produced from said comparator means with a reference value .alpha. and a produces a coefficient k; andsaid level-varying means varies the level of the edge crispening signal according to the coefficient k produced from said decision means.