Patent ID: 9721329
Date: 2017-08-01
CPC Classifications: G06T

Claim:
1. A method of denoising an image represented by a digital signal representation, the method comprising the steps of: creating at least one approximation image at at least one scale by applying a multi-scale decomposition algorithm to the image wherein all details of the at least one approximation image at a scale representing grey values of pixels of the image have been omitted; creating translation difference images by pixel-wise subtracting values of the at least one approximation image at a scale s and values of a translated version of the at least one approximation image; applying a denoising operator to translation difference values of the translation difference images so that the translation difference values are modified as a function of an estimated local signal-to-noise ratio to provide denoised translation difference images; computing at least one denoised center difference image at a specific scale by combining the denoised translation difference images at scale s or a finer scale; and computing a denoised image by applying a reconstruction algorithm which reverses the multi-scale decomposition algorithm to the at least one denoised center difference image; wherein the estimated local signal-to-noise ratio is estimated by comparing a translation difference to a selection of translation differences in a local neighborhood of the translation difference.