20 March 2015 Tchebichef moments based nonlocal-means method for despeckling optical coherence tomography images
Author Affiliations +
Speckle reduction in optical coherence tomography (OCT) images plays an important role in further image analysis. Although numerous despeckling methods, such as the Kuan’s filter, the Frost’s filter, wavelet based methods, anisotropic diffusion methods, have been proposed for despeckling OCT images, these methods generally tend to provide insufficient speckle suppression or limited detail preservation especially at high speckle corruption because of the insufficient utilization of image information. Different from these denoising methods, the nonlocal means (NLM) method explores nonlocal image self-similarities for image denoising, thereby providing a new method for speckle reduction in OCT images. However, the NLM method determines image self-similarities based on the intensities of noisy pixels, which will degrade its performance in restoring OCT images.

To address this problem, the Tchebichef moments based nonlocal means (TNLM) method is proposed for speckle suppression. Distinctively, he TNLM method determines the nonlocal self-similarities of the OCT images by computing the Euclidean distance between Tchebichef moments of two image patches centered at two pixels of interest in the prefiltered image. Due to the superior feature representation capability of Tchebichef moments, the proposed method can utilize more image structural information for the accurate computation of image self-similarities. The experiments on the clinical OCT images indicate that the TNLM method outperforms numerous despeckling methods in that it can suppress speckle noise more effectively while preserving image details better in terms of human vision, and it can provide higher signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), equivalent number of looks (ENL) and cross correlation (XCOR).
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Wanying Jiang, Wanying Jiang, Wenqi Xiang, Wenqi Xiang, Mingyue Ding, Mingyue Ding, Xuming Zhang, Xuming Zhang, "Tchebichef moments based nonlocal-means method for despeckling optical coherence tomography images", Proc. SPIE 9413, Medical Imaging 2015: Image Processing, 941327 (20 March 2015); doi: 10.1117/12.2082449; https://doi.org/10.1117/12.2082449

Back to Top