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_JGreg77_
Participant
June 3, 2008
Answered

Low contrast on scanned pdf

  • June 3, 2008
  • 7 replies
  • 169739 views
I have a large number of documents that appear to have been scanned on grayscale. The background is white, but the text is gray and difficult to read.

Is there an easy way to increase the contrast of the document in pdf form?

So far, I have been able to print the document, and using the printer settings I can print high contrast, and darken the image, but then I have to re-scan it. This is a waste of paper and time.

I can also save it as a tiff, but it splits into multiple pages, then I have to fix each page and recombine into a pdf. very time consuming!
    Correct answer Admin_001

    You can generally enhance the contrast of a scanned document in Adobe Acrobat using the: PREFERENCES/ACCESSIBILITY / REPLACE DOCUMENT COLORS drop down menu.

    7 replies

    I
    Ismaciil_Maxamed7622
    Participant
    February 24, 2025
    1aad.pdf
    N
    Nathanael5E65
    Participant
    April 7, 2021

    I'm leaving this comment here for any future users needing help solving this problem as I did. Fortunately I found that some of the most common image editing software applications can open PDF's.

     

    If you open your PDF in GIMP you can then adjust contrast/brightness, curves, levels, you name it.

    A
    Admin_001Correct answer
    Participant
    August 3, 2020

    You can generally enhance the contrast of a scanned document in Adobe Acrobat using the: PREFERENCES/ACCESSIBILITY / REPLACE DOCUMENT COLORS drop down menu.

    D
    DOMoore
    Participant
    February 3, 2021

    Thanks!!!! Worked great to darken the text on my faded-looking scan!

    Mattee1960
    Mattee1960
    Inspiring
    March 27, 2020

    I found a way to do this but I bought a old version of Photoshop to do it.  If you have photoshop, let us know and I will attempt to explan the steps, Im a beginner learning to decrease book file size create a PDF library from my books, mostly from mixing all the good ideas other posters have made.... I have learned alot over the past 4-5 months, eventhough I only half way know what I am doing!

    Mattee

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    Bill12
    Inspiring
    June 4, 2008
    There is a color conversion under the TOOLS>Print Production. You could also try printing to a new PDF with the B&W option selected.
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      _JGreg77_Author
      Participant
      June 4, 2008
      Thank you for your response.

      I tried many of the existing options, the only thing that seems to work is going to tiff, fixing the color, then going back to pdf.

      It seems like a long way around, I was just hoping for a better way, or at least a way to automate this.
      B
      Bill12
      Inspiring
      June 3, 2008
      Not easy in Acrobat. That is a job best done by a graphics editor. You could try printing to B&W or using some of the color conversion options under the tools to convert it, but do not expect magic.
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