Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We have here a large industrial printer/copier that also scans pages into PDFs. Unfortunately it scans crookedly, just a little bit.

I know there is software out there that straightens out images. Is there something that will do the same for PDF files?

share|improve this question
Considering how PDF works at a programmatic level I say you are better off buying better hardware. There is no such thing as a line in PDF. Everything works off of coordinates. At best a programmatic solution would work in most cases, but not all. – P.Brian.Mackey May 31 '11 at 18:54
don't know how old this forum is. i was wondering the same thing and it turns out that you can "optimize scanned pdf" on acrobat pro. you can find that under the "document" menu. hope this helps. – user102364 Oct 21 '11 at 2:32
up vote 2 down vote accepted

I believe that Adobe Acrobat can rotate pages, otherwise I know Photoshop can, but that would be one page at a time.

share|improve this answer
perhaps in the pro version, not in the free – peter Aug 7 '12 at 8:25
Correct. Adobe Acrobat Pro or Standard will allow it. Adobe Acrobat Reader will not. – Alan Shutko Sep 15 '13 at 19:44

There is a setting in adobe acrobat that does OCR for the pages. Part of the OCR process is straightening. I do not know if it exists as its own process/program.

  1. if it's a scanned document then 'Optimise Scanned PDF' under the Document menu will attempt to correct (only if there's just one scanned object on the page)

From the Adobe forums, might still work, at least worth a shot.

share|improve this answer

"Optimize Scanned PDF" under Document will straighten out the pages.

share|improve this answer
What do you mean "under Document"? The "Document" menu of some piece of software? What piece of software? – David Richerby Oct 2 '15 at 9:32

I personally would export the images (Acrobat Standard or Pro can export all bitmaps from a PDF, or use pdftk.

Correct the images using whatever photo editor you normally use, then create a new PDF (using either of the tools above).

share|improve this answer
This should work, but the OP seems to be looking for an automated solution rather than a manual process. – P.Brian.Mackey May 31 '11 at 20:16
There are various image editors that can batch-fix slightly rotated images. There are also ways to batch-import pics and make a new PDF. Granted it's not a perfect solution. – CarlF Jun 1 '11 at 12:57

For ones that stumble upon this I had success using unpaper

A script I quickly come up for my needs to extract text can be customized and improved. (For sure the crop values will differ;)

Overall I can say unpaper it's definitely useful tool to have but you need to fiddle a little with the parameters and doesn't fix pages that start to bend in the middle.

share|improve this answer

The best software that I've seen for this is BlueBeam Revu, which allows you to draw a line that should be horizontal. I wasn't able to produce the same result with Acrobat Pro.

The software can be purchased here:

The cost is currently $219 for the standard version.

share|improve this answer
Could you please at least include a link to said piece of software? A description on how to achieve it would also be nice. – slhck Jun 26 '14 at 5:40

For scanned hard copies that were skewed when converting to .pdf the OCR function under Documents > OCR Text Recognition > Recognise Text Using OCR works very well.
This is an Acrobat Pro 9 menu path.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.