A Locally Tuned Nonlinear Technique for Color Image Enhancement

Abstract:- An innovative technique for the enhancement of digital color images captured under extremely non-uniform lighting conditions is proposed in this paper. The key contributions of this technique are adaptive intensity enhancement, contrast enhancement and color restoration. Simultaneous enhancement of extreme dark and bright intensity regions in an image is performed by a specifically designed Locally Tuned Sine Non-Linear (LTSN) function. The intensity of each pixel’s magnitude is tuned based on its surrounding pixels to accomplish contrast enhancement. Retrieval of the color information from the enhanced intensity image is achieved by a linear color restoration process which is based on the chromatic information of the input image. Experimental evaluations show that the proposed algorithm can be effectively used for improving the visibility of night time surveillance video sequences with frames having extreme bright and dark regions. Key-Words:- dynamic range compression, intensity transformation, image enhancement, adaptive intensit