Sonar image preprocessing based on morphological wavelet transform

Sonar image preprocessing is the key step in the recognition and location system. In this paper we gave a new morphological wavelet for sonar gray image preprocessing. Firstly, made midpoint filter as the low-pass filter of morphological wavelet; then under the perfect reconstruction, constructed the morphological midpoint wavelet transform in the multiresolution analysis framework; finally enhance it by the lifting scheme. In the simulation experiment, we made its application to the sonar image preprocessing, and the performance of the proposed method is much superior to the existed wavelet transform both in high SNR or low SNR, also its edge-preserving effect is outstanding.