An apparatus for driving a liquid crystal display includes a picture quality improving unit that extracts a brightness component from first data, analyzes the brightness using the extracted brightness component, and generates second data having a contrast in accordance with the analyzed brightness. The contrast of the second data is extended from that of the first data. A timing controller rearranges the second data to supply the second data to a data driver. A backlight supplies the light to a liquid crystal panel in accordance with a driving current. An inverter supplies the driving current to the backlight.