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I know of several mobile apps designed to tidy up photos of documents, snapped directly from a phone camera, but I'd like a PC program to do the same thing. I already have a bunch of photos of documents as image files on my PC, which are at higher quality than my phone could ever take!

I can do this in Photoshop fairly easily but it takes time; I would like something more automatic, something that'll assume I have a photo of one rectangular thing, and work out the correct transform for me.

Absolute best form would be a program that can take image file paths as command line arguments and pump out fixed images without interaction, or a minimal GUI app with ability to work in batches. I don't want to have to spend ages setting up each conversion.

I would prefer for the output to be image files but PDFs would be fine too.

Platform needs to be Windows.

  • What's the difference between perspective correction and rotation? Also, what can't done automatically in Photoshop? – Franck Dernoncourt Nov 2 '14 at 14:28
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    By 'perspective correction' I mean that the camera is never perfectly flat on to the document so there's a little (sometimes a lot!) of perspective warping, which isn't as simple to correct as applying rotation - it's skew, plus a bit of magic. This kind of thing: photoshopessentials.com/photo-editing/keystoning – Ben Hymers Nov 2 '14 at 15:16
  • Thanks, I wasn't aware it was called keystone correction! – Franck Dernoncourt Nov 2 '14 at 15:26
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You can use ImageMagick (Free, open source, cross-platform, CLI) to post-process all your scanned images at once:

  • Ah, I've used ImageMagick for some format conversion before, didn't know it could do this kind of thing. I'll investigate - thanks! – Ben Hymers Nov 2 '14 at 15:19
  • ImageMagick is a great piece of software, but Adobe Photoshop is probably even better and can be scripted/automated as well :) – Franck Dernoncourt Nov 2 '14 at 15:28
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You could use python and OpenCV to detect the document orientation and perspective, assuming that the document will normally be rectangular and have the longest edges vertical quicker on a grey scale version - this will give you the transform values to use and then you can apply the same.

There is an example, (in C), on SO: https://stackoverflow.com/questions/22656698/perspective-correction-in-opencv-using-python

0

2 options I found so far:

1- Free Option: PerspectiveImageCorrection. https://sourceforge.net/projects/perspectiveimg/ 2- Paid Option: Perspective Pilot. https://www.colorpilot.com/perspective.html

and to cover all requirements, I would use option 1 and a free software called "PhotoScap" combined.

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