Patent ID: 8041144

Claim:
An apparatus for improving visibility of an image, the apparatus comprising: a LUT (lookup table) generating module to generate, using one or more processors, a LUT having image data in a high illuminance environment corresponding to image data of an input image set therein so as to increase lightness and chroma of the input image according to external illuminance; an image mapping module to map the image data of the input image into the image data in the high illuminance environment according to the generated LUT; and a local contrast increasing module to increase a local contrast of the mapped image data using a parameter for adjusting the local contrast according to the external illuminance, wherein the local contrast increasing module comprises: a lightness computing module to compute the lightness of the input image and a lightness of the image into which the input image has been mapped by the image mapping module; a low pass filter to filter luminance data of each of pixels constituting the input image and luminance data of each of pixels constituting the image into which the input image has been mapped; an index computing module to compute a contrast ratio index and a contrast index with respect to the input image according to the filtered luminance data and average luminance data with respect to all of the pixels constituting the input image; and a local contrast compensating module to increase a local contrast of a pixel region corresponding to the parameter according to the contrast index and the contrast ratio index.