Apparatus and method for estimating and converting illuminant chromaticity using perceived illumination and highlight

摘要

A method and apparatus for estimating illuminant chromaticity and a method and apparatus for converting the estimated illuminant chromaticity into desired illuminant chromaticity using software are provided. The apparatus for estimating illuminant chromaticity includes an image input unit for receiving a color image, a highlight detector for extracting highlight regions from the color image, a highlight parameter calculator for mapping the highlight regions to chromaticity coordinates and calculating geometric presentation parameters of the shape of the distribution of chromaticity coordinates, a perceived illumination illuminant chromaticity estimator for estimating illuminant chromaticity in the color image using a perceived illumination estimate scheme, and a correct chromaticity calculator for selecting a predetermined number of geometric presentation parameters near the illuminant chromaticity estimated by the perceived illumination illuminant chromaticity estimator among the geometric presentation parameters and calculating final illuminant chromaticity using the selected geometric presentation parameters. The method for estimating illuminant chromaticity using perceived illumination and highlights is used for estimating illuminant chromaticity from a color image. This method, which is a combination of two kinds approaches, a perceived illumination estimate scheme and a highlight estimate scheme, considers the characteristics of highlights based on stable illuminant chromaticity estimated from perceived illumination, thereby improving accuracy.