Effective Speckle reduction and structure enhancement method for retinal OCT image based on VID and Retinex

Improving the quality of images is one of the key tasks in Optical Coherence Tomography (OCT) imaging technology. Low contrast and speckle noise are two major factors affecting the accuracy of OCT measurement. In this paper, an effective speckle reduction and structure enhancement method is proposed based on variational image decomposition (VID) and multi-scale Retinex (MSR). To be specific, we propose a new variational image decomposition model BL-G-BM3D to decompose the OCT image into background part, structure part and noise. Then the structure part is enhanced by MSR and the background part is used to generate a filter mask by fuzzy c-means clustering algorithm. Experimental results show that the proposed method performs well in speckle reduction and structure enhancement, with better quality metrics of the SNR, CNR, and ENL and better fine detail retention than shearlet transform method and BM3D method.