Denoising of x-ray imagery with spatially-varying estimates of noise variance

摘要

We described a way to use a block-matching 3-D denoising algorithm to reduce noise in x-ray imagery. We first filtered an image multiple times using different estimates of the noise variance. From a simple estimate of the denoised image, we then estimated the noise variance at each pixel of the image. Using this approach, we obtained improved results when compared to using a single value of estimate for the noise variance. Even a small number of quantization levels of the estimates of the noise showed improved results.