I have been using Paint.net to crop and reduce the noise on some scanned old club handbooks, printed in late 1800 & early 1900.
Using effects > 'reduce noise' with radius 200 & strength 1 does the job perfectly. The problem I have is that I have about 60 books each of which is some 100 pages so doing this all manually is not really feasible.
I have found Imagemagick and it seems to do the batch processing of crop well, but I can't find the equivalent function to 'reduce noise'.
I think I should use the -blur function in Imagemagick but that requires radius & sigma. So my question is, assuming Blur is the right equivalent function, what is the sigma value that equates to strength 1 in paint.net?
Also if anyone uses Imagemagick and can suggest a better function to reduce noise that would be great.