Abstract: A method and apparatus for contrast control is provided. The apparatus includes a cumulative density function which provides a second cumulative density function modified from a first cumulative density function based on a first luminance histogram of an input image; a transformer function provider which provides a transform function based on the first cumulative density function and the second cumulative density function; a compensation unit which compensates the transform function based on a predetermined illumination level; and a transform unit which transforms a luminance distribution of the input image based on the compensated transform function.

Abstract: An image compensating system, medium, and method, including, a shadow area compensating system, medium, and method which may significantly increase the luminance of each pixel in a dark area with respect to pixels positioned in the vicinity of the corresponding pixel and slightly increase the luminance of each pixel in a bright area. The shadow area compensating method includes calculating a representative luminance Lav of each pixel having image information by reflecting the luminance of the corresponding pixel and the luminances of pixels positioned in the vicinity of the corresponding pixel, determining a compensation luminance ratio using the calculated representative luminance, and increasing an output luminance on the basis of the compensation luminance ratio.

Abstract: An image processing apparatus and method to reduce the deterioration of visibility of an image displayed on an image display device occurring under various lighting conditions when the brightness of ambient light is brighter than that of the image display device, and includes a sensor to sense the brightness of an external light, a unit to store a luminance-contrast model curve representing an optimal contrast value for a particular luminance for each brightness of the external light, a unit to determine a target luminance value according to the sensed brightness of the external light, to obtain a contrast value corresponding to the target luminance value with reference to the luminance-contrast model curve corresponding to the sensed brightness, and to adjust an input image to have the target luminance value and the obtained contrast value, and a unit to adjust the saturation of the adjusted input image according to the

Abstract: A method of enhancing contrast includes obtaining a first luminance histogram of an input image; generating a second luminance histogram through pixel redistribution for the first luminance histogram; computing a conversion function based on both a first cumulative density function based on the first luminance histogram and a second cumulative density function based on the second luminance histogram; and changing the luminance distribution of the input image based on the conversion function.

Abstract: A method and display device for correcting spatial non-uniformity in a display device are provided.. The method includes receiving color signals of a pixel to receive the pixel, extracting correction data for correcting adjacent representative color signals which represent areas adjacent to the received pixel, and correcting the adjacent representative color signals using correction data and correcting the color signals of the pixel using the corrected adjacent representative color signals.