olaeblue

Thanks Rick, Can you confirm whether the 'reduce noise' function is a specialist blur and the sigma values, or what is the underlying function(s), so I can try & recreate in imagemagick. Reduce noise is so effective that if I can do this with IM that would make my day :-) Andy

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. Thank you