Disclosed is a color signal processing apparatus in which at least three types of color signals corresponding to filters are received from a solid-state image pickup element on which at least three types of color filters are formed, and linear matrix conversion of the at least three types of color signals...http://www.google.co.uk/patents/US5202756?utm_source=gb-gplus-sharePatent US5202756 - Color signal processing apparatus using plural luminance signals
