1. A method of driving an organic light-emitting diode (OLED) display comprising a plurality of pixels, the method comprising: receiving input image data; calculating a load value corresponding to a driving amount of the input image data; calculating a luminance adjustment value for each of the pixels based at least in part on the load value and a voltage drop proportional value of each of the pixels, wherein the voltage drop proportional value corresponds to a ratio of a voltage drop value to a maximum voltage drop value; adjusting the input image data based on the luminance adjustment value; generating output image data based at least in part on the adjusted input image data; and displaying an, image corresponding to the output image data, wherein the luminance adjustment value is determined by multiplying the voltage drop proportional value by a ratio of the load value to a maximum load value.