A
system is provided for using raw
grayscale image data, representing images to be displayed in successive frames, to drive a display having pixels that include a drive
transistor and an
organic light emitting device. The
system defines high and low ranges of raw
grayscale image data, and determines whether the raw
grayscale image data for each pixel falls within the high range or the low range. Raw grayscale image data that falls within the low range is converted to higher grayscale values, and the pixels are driven with currents corresponding to the higher grayscale values during time periods that are shorter than complete
frame time periods. Raw grayscale image data that falls within the high range is converted to higher grayscale values, and the pixels are driven with currents corresponding to the higher grayscale values during time periods that are shorter than complete
frame time periods and different from the time periods of the low range image data. When the raw grayscale image data is adjusted according to a preselected gamma curve before using that data to drive the pixels, the high and low ranges may be selected according to how well the gamma curve corrects the raw grayscale image data within the ranges.