The present invention provides an image compensation circuit generating output image data to drive a display panel having pixels. The image compensation circuit includes first/second control circuits and first/second compensation circuits. The first control circuit may receive input image data for the pixels and generate a plurality of first compensation values corresponding to compensation for voltage drop on the display panel according to the input image data. The first compensation circuit may compensate the input image data for the pixels with the first compensation values. The second control circuit may receive the first compensation values from the first control circuit and generate a plurality of second compensation values corresponding to compensation for channel length modulation (CLM) effect of the pixels according to the first compensation values. The second compensation circuit may compensate the input image data for the pixels with the second compensation values, to generate the output image data.