A circuit for performing demura operation for a display panel of a computerized device is provided. The circuit includes an arithmetic unit for converting input luminance codes (e.g., grayscale codes) that correspond to a first group of pixels to output luminance codes by computation, and a lookup table unit having a storage module for mapping input luminance codes that correspond to a second group of pixels to output luminance codes. Such a configuration uses the lookup table unit to replace some computations for demura operation, thereby reducing time and power required for demura operation.