Patent ID: 7365720

Claim:
A calibration method for calibrating a fixed format emissive display device having a plurality of pixels, each pixel comprising at least three sub-pixels for emitting light of different real primary colors, the method comprising: determining, for each real primary color separately, a virtual target primary color, determining a color gamut defined by the determined virtual target primary colors, adjusting the drive currents to the sub-pixels to achieve a color inside the determined color gamut, and determining a target luminance for each virtual target primary such that the target luminance is set equal to the maximal luminance that can be achieved by all or substantially all of the real primaries able to realize the target luminance of the corresponding virtual primary wherein determining the color co-ordinates of a virtual target primary color comprises determining a center of gravity of a cloud formed by the color co-ordinates of the corresponding real primary colors of all pixels of the display device.