Morphological and wavelet filtering for shear-beam image restoration

Shear beam imaging is a coherent reflective imaging technique which inherently contains signal dependent speckle noise, and removal of the speckle using a minimal number of frames is the major concern of this paper. In the past, several methods have been used to eliminate this noise. The complexity of the algorithms ranged from a simple nonlinear median filter to complex linear and nonlinear models. Here, fast morphological and wavelet filters are proposed and are shown to remove speckle better than the previous methods. The morphological filters are non-linear in nature and computationally efficient, thus making them quite attractive. This paper describes the morphological and wavelet techniques used and demonstrates the superior performance of these filters as compared to the previously used ones.