METHOD AND APPARATUS FOR CONVERTING RGB DATA SIGNALS TO RGBW DATA SIGNALS IN AN OLED DISPLAY

A method for converting input RGB data signals to output RGBW data signals for use in an OLED display is disclosed. In the OLED display, each pixel has three color sub-pixels in RGB and one W sub-pixel. Input RGB data signals in signal space are normalized and converted into input data in luminance space. A baseline adjustment level is determined from the input data and is used to compute baseline adjusted data in luminance space. After being converted from luminance space into signal space, baseline adjusted data in RGBW are represented by N binary bits presented to the four sub-pixels. To suit the color characteristics of the display, color-temperature correction to the output signals is also carried out. In luminance space, the maximum color-temperature corrected output data fall within the range of 0.4/k and 0.5/k, with k being the ratio of W sub-pixel area to the color sub-pixel area.