Patent ID: 8049795

Claim:
A lens shading compensation apparatus comprising: a pixel value analyzing part generating luminance information from primitive image data, the primitive image data being color interpolated so that each pixel has red, green and blue components, the luminance information being generated for each color; an auto exposure value setting part measuring an average luminance of a portion of a pixel array through the luminance information and setting the average luminance as an auto exposure value, the portion of the pixel array being positioned around a first central pixel of the pixel array; a central pixel detecting part detecting a second central pixel from a lens shading image corresponding to the luminance information; a table generating part partitioning the pixels in units of blocks according to the distance from the second central pixel, generating and storing a compensation value per block corresponding to the auto exposure value; a pixel location calculating part calculating the distance between an object pixel and the second central pixel; a mask image generating part producing a compensation value for the object pixel by using the compensation value per block corresponding to the distance between the object pixel and the second central pixel, and creating a shading mask image per color; and a compensation part generating pixel compensation information by combining the primitive image data with the shading mask image, wherein the central pixel detecting part detects the second central pixel by using intersection points on a closed curve, the curve being produced by a luminance boundary value, the luminance boundary value set to be located between a minimum value and a maximum value of the luminance information on each pixel of the pixel array, the closed curve being intersected by a horizontal central line or a vertical central line both passing through the first central pixel at the intersection points.