Search found 12 matches

by pchun
2018-02-01T07:47:03-07:00
Forum: Users
Topic: Syntax problem
Replies: 2
Views: 1210

Syntax problem

I am playing a bit with different examples from IM documentation and keep encountering a problem with all examples where this style of syntax is present (example directly copied from documentation) convert zelda_text.jpg \( zelda_text_mask.gif -background white -alpha shape \) -flatten zelda_mask_ov...
by pchun
2017-12-20T11:12:20-07:00
Forum: Users
Topic: Reproduce Book Restorer lighting correction
Replies: 13
Views: 5075

Re: Reproduce Book Restorer lighting correction

I did some additional research on this problem and I think managed to make some progress though in a somewhat circuitous way. Generally I tried to move forward with the idea outlined by Anthony here http://www.imagemagick.org/discourse-server/viewtopic.php?t=21906 , that is divide the image by a blu...
by pchun
2017-12-16T05:27:59-07:00
Forum: Users
Topic: Smoothly denoise an image of a scanned page
Replies: 11
Views: 3485

Re: Smoothly denoise an image of a scanned page

One more point. I sought more information about Paint.Net denoise filter my sample fragment had been processed with. Turns out it's just a simplified wrapper for Greycstoration algorithm. Is it by any chance available in IM?
by pchun
2017-12-14T07:48:54-07:00
Forum: Users
Topic: Smoothly denoise an image of a scanned page
Replies: 11
Views: 3485

Re: Smoothly denoise an image of a scanned page

I would like to ask Snibgo's help to clarify his XY approach. How do I actually go about it? I processed the page with slopeXY.bat, then put the .miff file through the transformations in the code snippet and produced the second .miff file. How do I get filtered page image from the second .miff then?...
by pchun
2017-12-12T10:42:00-07:00
Forum: Users
Topic: Smoothly denoise an image of a scanned page
Replies: 11
Views: 3485

Re: Smoothly denoise an image of a scanned page

Thank you Fred, actually I did try to roughshod it using several iterations of -enhance in a row, but it's awfully slow (at least on my system) if I process a whole page not just a fragment.
by pchun
2017-12-12T10:22:39-07:00
Forum: Users
Topic: Smoothly denoise an image of a scanned page
Replies: 11
Views: 3485

Re: Smoothly denoise an image of a scanned page

Thank you, I will try it. Though what is spm_sxy.miff spm_sxy2.miff in your code? I am not a professional so I didn't think of noise reduction in terms of it's scientific definition. May be what I am trying to get at shouldn't be called noise reduction from scientific point of view at all. My goal w...
by pchun
2017-12-12T08:54:09-07:00
Forum: Users
Topic: Smoothly denoise an image of a scanned page
Replies: 11
Views: 3485

Smoothly denoise an image of a scanned page

Here is a fragment of a scanned page image. The paper is rather grainy so I am trying to smoothly reduce background noise while keeping foreground text as much intact as possible. https://drive.google.com/file/d/1ts2IK75yKUqpbTN7Xnxqn3t-N31qLj4S/view?usp=sharing This task appears to be rather straig...
by pchun
2017-11-29T09:59:49-07:00
Forum: Users
Topic: Reproduce Book Restorer lighting correction
Replies: 13
Views: 5075

Re: Reproduce Book Restorer lighting correction

Thanks for your time, Fred. I will try it. To illustrate my point about complexities of working with book scans. Below is a sample page (low quality rough grainy paper and the print is smudged to boot). I textcleaner'ed it with textcleaner -f 20 -o 10 -b "image" -S 100. You can see it doesn't look n...
by pchun
2017-11-28T01:49:20-07:00
Forum: Users
Topic: Reproduce Book Restorer lighting correction
Replies: 13
Views: 5075

Re: Reproduce Book Restorer lighting correction

I don't want it to show through and would be glad to get rid of it altogether. The problem is sometimes I have to deal with much worse cases of bleed through effect when foreground text is not that different from background text. The whole problem with preserving background color of scanned pages in...
by pchun
2017-11-27T22:46:56-07:00
Forum: Users
Topic: Reproduce Book Restorer lighting correction
Replies: 13
Views: 5075

Re: Reproduce Book Restorer lighting correction

Thanks again, Fred. Book Restorer is a rather antiquated piece of software, developed in early 2000s by the French company i2s http://www.i2s-digibook.com/ . Their main line of business is producing professional book scanners, so they specifically designed Book Restorer for post-processing of scanne...
by pchun
2017-11-27T10:40:20-07:00
Forum: Users
Topic: Reproduce Book Restorer lighting correction
Replies: 13
Views: 5075

Re: Reproduce Book Restorer lighting correction

Thank you very much, Fred. I didn't pay attention to the -b key in textcleaner description. It works great. Probably it's the easiest way to even background after all. Though speaking of Book Restorer how do you think their specific effect was achieved? It somehow significantly reduces the differenc...
by pchun
2017-11-26T01:19:57-07:00
Forum: Users
Topic: Reproduce Book Restorer lighting correction
Replies: 13
Views: 5075

Reproduce Book Restorer lighting correction

Questions about improving images of scanned book pages were posted here many times before, but please bare with me. I scan books with a V-cradle photo-scanner (Internet Archive - style design). Unfortunately the lighting is not uniform, so brightness is uneven across the scanned page. I am aware of ...