ABSTRACT
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.
Keywords: - Contrast enhancement, DWT, Image equalization, SVD, Wavelet thresholding