Adaptive wavelet transformation for speckle reduction in Optical Coherence Tomography images

This paper proposes a novel approach for speckle reduction and sharpness preservation of Optical Coherence Tomography (OCT) images based on adaptive wavelet filter. At the first step of our approach, 2-dimensional wavelet sub-band coefficient components are obtained by using wavelet decomposition. Then, coefficient suppression matrices for each sub-band image are determined according to the statistical properties of the sub-band component and corresponding components in different decomposition levels. Relying on this result, the new wavelet coefficient components are produced respectively. Finally, the estimated image is reconstructed by taking the inverse wavelet transform of the processed coefficients. The experimental results demonstrate a significant reduction of speckle noise and enhancement of OCT images.