Legacy ImageMagick Discussions Archive

I am scanning some old documents and need to pre-process before OCR. I have found in paint.net a function called reduce noise where with a radius of 200 and a strength of 1 (strength is range 0 to 1) I can move from image 1 to image 2 (these are low res versions of the large tif files I actually have but give the general impression) basically cleaning up the grey background to white.

http://www.yrc.org.uk/data/files/downloads/orig.jpg
Image 1

http://www.yrc.org.uk/data/files/downloads/clean.jpg
Image 2

I have about 600 of these to do! What is the equivalent function in Imagemagick. -despeckle doesn't seem to do it & I think -blur might be right, but can't get right effect.

Any help gratefully received.

To clean up grayscale scans of documents, I've been using this command - although I wasn't then running them through an OCR program: You would have to play with the threshold value to suit your images - it converts the image to black and white. The output file format should not be JPG because it will introduce compression artifacts which will probably confuse the OCR engine.

Pete

you might take a look at my bash script textcleaner at the link below

Thanks. Couldn't use bash script as windows person, but the explaination of what it does allowed me to build a suitable command line.