Optimized-Bayesian-Nonlocal-means-with-block(OBNLM)

Optimized bayesian nonlocal-means algorithm for denoising ultrasound image

Description

• BayesianNLM.m : the OBNLM algorithm
• getPearsonDistance.m: compute the pearson distance based bayesian framework
• ImgNormalize.m: pre-processing the image (histogram stretching)
• testBayesianNLM.m: test our algorithm using the input (noisyImage.png) and get the output (despeckledImage.png)

Reference Paper

Coupé, Pierrick, et al. "Nonlocal means-based speckle filtering for ultrasound images." IEEE transactions on image processing 18.10 (2009): 2221-2229.

Basic Principle

The blockwise Nonlocal Means algorithm is completed. The basic principle is shown below:

Object Function: with

: the blockwise of image

:the pearson distance between blockwise

Results

The original ultrasound image (with speckle) vs the despeckled ultrasound image: