An image processing device includes a gatherer configured to receive image data and gather statistics of color data from the image data. The image processing device includes a processor configured to analyze the statistics of the color data to determine whether the image data includes single color data or multi color data, determine a first gain value to perform an automatic white balance if the image data includes multi color data, and determine a second gain value different from the first gain value using a gain table if the image data includes single color data. The image processing device includes a gain applier configured to apply the first gain value or the second gain value to the color data.