Patent ID: 7932883

Claim:
A method of mapping a four-primary input signal (IS) to sets (Pij) of four sub-pixels (RPij, GPij, BPij, WPij) of a display device (DD), wherein the four-primary input signal (IS) comprises a sequence of input samples (Sij) each comprising a value for a first component (Rlij), a value for a second component (Glij), a value for a third component (Blij), and a value for a fourth component (Wlij), and wherein the sets (Pij) of the four sub-pixels comprise a first sub-pixel (RPij) for supplying light having a first primary color (R), a second sub-pixel (GPij) for supplying light having a second primary color (G), a third sub-pixel (BPij) for supplying light having a third primary color, and a fourth sub-pixel (WPij) for supplying fourth light having a fourth color (W), the first, second, third and fourth color all being different, and the fourth color being within the color gamut of the first, second, and third color, the method comprising sub-sampling (MAP) the input samples (Sij) of the four primary input signal (IS) (i) by assigning, via mapping, a first component (RI 11 ), a second component (GI 11 ), and a third component (BI 11 ) of a particular input sample (S 11 ) to the first (RP 11 ), second (GP 11 ) and third sub-pixel (BP 11 ) of a particular set (P 11 ) of four adjacent sub-pixels, respectively, and (ii) by assigning, via, mapping, a fourth component (WI 12 ) of a further input sample (S 12 ) to the fourth sub-pixel (WP 11 ) of said same particular set (P 11 ) of the four adjacent sub-pixels, wherein the particular input sample (S 11 ) and the further input sample (S 12 ) are associated with adjacent positions on the display device (DD), and wherein the further input sample (S 12 ) is adjacent to, separate and distinct from, the particular input sample (S 11 ) in the input samples (Sij) of the four primary input signal (IS).