I mentioned in my original post that I am going to show results of comparing PCA/SVD, NNMF, and ICA over image de-noising. This blog post does that : "Comparison of PCA, NNMF, and ICA over image de-noising".
Below are given the most important comparison images.
Visual comparison of de-noised images
Next we visualize the ICA de-noised images together with the original images and the SVD and NNMF de-noised ones.
There are several ways to present that combination of images.
Comparison using classifiers
We can further compare the de-noising results by building digit classifiers and running them over the de-noised images.
We can see that with ICA we get better results than with PCA/SVD, probably not as good as NNMF, but very close.