AMOLED and driving method thereof

The present invention is a first step of performing gray-scale determination of the raw image data relates to a driving method and an organic electroluminescent display device; A second step of determining the one of the picture type of the low-gradation image, the image relay tank, the high gradation image according to the distribution of the determined gray level; And a third step of selecting each other one of the plurality of different gamma curves according to the determined image type; And a fourth step of converting the raw image data into data voltages using the gamma reference voltages corresponding to the selected gamma curve; For a driving method, and provides an organic light emitting display device for its realization, less many of the dark areas in the display image the bright portion image of the organic light emitting display device including a fifth step of displaying the image to the data voltage the further emphasize the bright portion and can improve the sharpness, it is also an advantage that a bright portion of the display image can be reduced more image power consumption by giving visibility to lower the light emission luminance in the range that does not inhibit cases.