Paper Details

Devices which use underwater sound for communication or observation are generally mentioned to as SONARsystem. Basic principle for SONAR image formation is transmission of pulse energy into water medium and subsequentreception of any returned energy reflected from objects or seabed. But during this image formation considerable amount ofacoustic noise get added into sonar signals. The presence of acoustic noise distorts and degrades the accuracy of informationextracted from sonar images. Thus it is very essential to eliminate or reduce noise from sonar images before using thoseimages for various purposes. The main property of a good image denoising model is that it should completely remove noiseas far as possible as well as preserve edges. Discrete Wavelet Transform(DWT) is most powerful tool in image denoising.One of the most popular method in wavelet domain is thresholding the wavelet coefficients (using the Hard threshold or theSoft threshold) as introduced by Donoho. This paper presents a review of wavelet domain denoising techniques in non-linearcoefficient thresholding based methods. One of the key properties underlying the success of wavelet expansions tend toconcentrate the signal energy into a relatively small number of large coeffcients. This energy compaction property of thewavelet transform makes the wavelet domain attractive for signal processing.

Kharade Archana G, Prof. Rangole Jyoti V, “A Review on Wavelet Transform Based SONAR Image Denoising using Wavelet Thresholding”, International Journal of Advance Engineering and Research Development (IJAERD), Vol. 3, Issue 2, pp. 17-20, February 2016.