Two-dimensional noise reduction in optical coherence tomography based on the shearlet transform

Image denoising is a very important step in image processing. In recent years, a lot of image denoising algorithms have been proposed, several of them are transform domain based methods, such as wavelet, contourlet, and shearlet. Shearlet is a new type of multiscale geometric analysis tool, which can obtain a sparse representation of the image and produce the optimal approximation. The transform generates shearlet functions with different features by scaling, shearing, and translation of the basic functions. In this paper, we introduced shearlet transformation into optical coherence tomography images to reduce noise, and proposed a multiscale, directional adapted speckle reduction method. Experiment results showed the effectiveness of the proposed method.