Digital color encoder

Claim 1

A digital color encoder for synthesizing a composite color video signal of a modulated chrominance subcarrier, comprising: sampling signal generator means for generating a sampling clock signal having a frequency which is n times as high as a frequency of the chrominance subcarrier, where n is an integer greater than two, and for generating n-phase sampling signals respectively staggered in phase by 360/n degrees and having said subcarrier frequency; sampled primary color signal producing means for producing color image signals which are digital representations of respective primary colors, and are sampled at said frequency of said sampling clock signal; coefficient providing means for providing, in response to said n-phase sampling signals, predetermined coefficients which are digital representations of the respective staggered phases for the respective primary color image signals, said coefficients being determined as values which appear as coefficients to the respective primary color image signals as expressed in a formula indicative of the composite color video signal at the respective sampling phases; multiplying means for multiplying said sampled primary color image signals by said respective coefficients at the respective corresponding phases; and combining means for combining outputs from said multiplying means, thereby forming a synthesized color video signal.