Under Water Image Enhancement by Using Stationary Wavelet Transform

Abstract

This paper deals with a strategy to enhance underwater images based on a single image through fusion. This enhancement process involves three steps. In the first step, contrast adjustment is done on the degraded input image using histogram equalization in order to redistribute the lightness values, improve the local contrast and bring out the input image in more detail. In the second step white balancing algorithm is applied on the same degraded input image for the better exposedness of the dark regions and to improve global contrast while the finest details and edges are enhanced significantly. In the final step the outputs of step one and step two are fused using Stationary wavelet transform (SWT) algorithm.

Compare the performance of SWT technique with Wavelength Compensation and Image Dehazing (WCID) technique by determining the Peak-Signal to Noise Ratio (PSNR).