| 摘要 |
Digital images often have undesired color casts due to unusual illuminant sources. A color correction method is provided that uses adaptive segmentation to identify the presence of such casts, estimate their chromatic strength, and alter the image's near-neutral-color regions to compensate for the cast. The method identifies most major objects in a scene and their average color. A color space having an achromatic axis is provided with a default gray radius that is used for establishing bins of neutral color in a chromatic plane. The bins are populated with the pixels of the digital color image based on pixel chromaticity. A color histogram computed with chromaticity peaks for the pixels in the bins within the default gray radius. The default gray radius is adjusted to a gray radius based on the chromaticity peaks in the color histogram. The color cast is detected from a dominant chromaticity peak, or two chromatic peaks in the same chromatic quadrant, within the gray radius and color cast distance from the distance thereof from the achromatic axis. The color cast is removed from the pixels by subtracting the color cast distance from the color image in the color space and outputting a color cast removed color image. |
