Image Fusion with Contrast Enhancement Using DWT and SVD

Contrast is one of the important quality factors in image processing. Contrast is created by the difference in luminance reflected from two adjacent surfaces. In visual perception, contrast is determined by the difference in the colour and brightness of an object with other objects. If the contrast of an image is highly concentrated on a specific range, the information may be lost in those areas which are excessively and uniformly concentrated. This paper described a new contrast enhancement approach based on Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD) that results in quality improvement of low contrast images. The input image is decomposed into four sub bands using DWT and obtain singular value matrix of the low-low sub band image and finally reconstructs the enhanced image by applying IDWT.