Color image illumination compensation based on homomorphic filtering

Abstract

To eliminate the illumination influence to color image,an illumination compensation method based on homomorphic filtering is proposed.In frequency range,the homomorphic filtering is employed to process the image,and the Butterworth high pass filtering function is introduced into the homomorphic filter to design a new dynamic Gauss homomorphism filter.Then the luminance component of the image in YIQ color space is enhanced and the chrominance component maintains invariable,by which the high frequency component is increased while the low frequency component is reduced,the image quality drop caused by illumination insufficiency is relieved.Finally,the image illumination compensation is achieved.Experimental results demonstrate that the proposed method,which performs well in weakening illumination effect and improving image quality,is more effective to illumination compensation for color image than conventional Gauss high filtering and histogram equalization.