Speckle noise reduction of ultrasound knee biomarker with edge and detail preservation using improved diffusivity function

Anisotropic Diffusion (AD) is a well-known method for reducing the speckle noise, especially in an ultrasound (US) image. Nonetheless, its pertinent detail preservation ability remains insufficiently robust. We propose an AD method that poses emphasis both on edge and small detail preservation during speckle noise reduction of the US image. A new diffusivity function is proposed by having simultaneous concern on edge and important detail preservation of the US image. The diffusivity function is defined with the aid of comparison and scaling on top of the method of Black et al.. Mean absolute error (MAE) stopping criterion is used for automatic stopping of the diffusion process (number of iterations). For performance evaluation of the proposed AD method, ultrasound (US) image of knee joint cartilage is adopted. Qualitative analysis is performed by using human visual perception. Different performance metrics named as peak signal to noise ratio (PSNR), figure of merits (FOM), and structure similarity index measurement (SSIM) are computed for quantitative analysis of the proposed method.