Abstract: An organic light emitting display, and an image modification method may include an analog to digital image signal processor configured to output present digital image data, a frame data analysis unit electrically coupled to the image signal processor, the frame data analysis unit configured to receive the present digital image data and a present data summation value, and to output a new data summation value, a light emission time supply unit electrically coupled to the frame data analysis unit and configured to supply a light emission time in accordance with the new data summation value, and a light emission control driver electrically coupled to the light emission time supply unit and configured to output a light emission signal in accordance with the light emission time output from the light emission time supply unit.