[IPOL discuss] BM3D ready in dev. server

José Luis Lisani joseluis.lisani at uib.es
Thu Apr 28 23:26:09 CEST 2011

> I have a question:
> If I understand the demo, it adds noise to the input image,
> and then tries to remove it. Why can't we also ask
> the demo to remove just the noise that is already on the image?
the denoising algorithms (at least nl-means and dct denoising) assume 
known the noise level
(sigma) of the input images, which is a parameter of the algorithm.
The way to run the demos is:
- take a "clean" image (very low noise)
- add a known noise of level sigma
- denoise, using sigma as a parameter
- compare result and original image

Therefore, it doesn't make sense to use sigma=0 in the demo, because we are
asking the algorithm to denoise an image without noise.

In the future, a noise estimation algorithm will be used to estimate the 
of arbitrary input images, and this estimation will be used in the 
denoising algorithms.

José Luis

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