Patent ID: 8223180

Claim:
A method for processing received image data for displaying an image in a display window of a display unit comprising some subpixels each of which is to emit just one of a plurality of primary colors and other subpixels each of which is to emit a white light where the subpixels are to each have a luminance depending on the subpixel's state defined using a supplied subpixel value for the respective subpixel, areas of the display unit each having a corresponding gamut which is associated with a range of luminances that can then be output by the subpixels of the respective area during a corresponding time period, the method comprising: (A) testing, by a circuit, the received image data representing a set of areas to be displayed and sharing a corresponding gamut, where the to be displayed set of areas includes a first area A1 comprising a respective first plurality of the subpixels, the set of areas also comprising respective second and third areas adjacent to and respectively located at opposite sides of the first area A1, said testing determining if a gamut condition holds, which condition comprises, at a minimum, that in the first area A1 all of the respective subpixel values of the respective first plurality of subpixels are within the corresponding gamut while in each said adjacent second and third areas, the one or more subpixel values are not all within the corresponding gamut; (B) if the gamut condition holds, then modifying, by the circuit, one or more of the subpixel values in at least one of said adjacent areas to thereby force all the subpixel values in said at least one of said adjacent areas into the corresponding gamut, and also reducing one or more subpixel values in the first area A1 to thereby prevent loss of displayed contrast as between the displayed luminance of the first area A1 and the displayed luminance of said adjacent areas; (C) if the gamut condition does not hold, then leaving, by the circuit, the one or more subpixel values in the area A1 unchanged or reducing, by the circuit, at least one of the subpixel values in the first area A1 by a smaller amount than if the gamut condition holds.