Cleaning up Scanned Images


I recently received this message from a legal technology consultant:

I have had several clients (and have wondered myself) why there’s no way to delete something from a PDF. For example, if I scan a document and want to delete the black marks made by the staple holes in the top left corner, I can’t do that without cropping the entire image.  What is the reasoning for not including a feature that would allow me to draw a box around those staple holes and delete them from the image? 

Actually, Adobe did include a feature to clean up scanned images!

You can easily clean up scanned images using the Redaction tool:
Mark for Redaction Tool
Normally, redactions appear as a black box which obscures the underlying document. Did you know that Acrobat can redact to “No Color” as well?

In this article, I’ll offer step-by-step instructions for cleaning up scanned PDFs using the Redaction tool in Acrobat Professional.

Using this workflow, you can easily delete staple marks, hole punches, shadows, dirt and more from PDFs.

Read on to learn how…

Using the Redaction Tool

I’ve written about using the Redaction tool before in my article, Acrobat 8 New Features: Redaction.

Redaction is the permanent deletion of data from a document. One little known Acrobat redaction feature is the ability to use “No Color” when redacting. This handy feature is great for cleaning up scanned images.

Follow these steps to use a “No Color” redaction for scanned image cleanup:

  1. Choose View—>Toolbars—>Redaction
    The Redaction toolbar will appear.

    Redaction Toolbar

  2. Click the Mark for Redaction tool

    Mark for Redaction tool

  3. Click and drag a rectangle around the items on the page you wish to remove. In this case, we’ll remove a hole punch.

    Mark the redaction area

    When you hover over the object, a black redaction mark appears:

    When hovering, the redaction mark will appear black.
    We’ll change the appearance from black to “no color”

  4. Right-click on top of the Redaction mark and choose Properties

    Getting to the Redaction Properties window

  5. The Redaction Properties window appears.
    (A) Change the fill color for the redaction mark to “No Color”
    (B) Optional: Check “Make Properties Default” to always redact to “No Color”

    Redaction Properties window

  6. Click OK.
    When you hover over your redaction mark, you will see a preview of the cleaned up area.

    The hole punch mark is gone!

    No more hole punch!

Using Acrobat 9? Use the Properties Bar

Instead of right-clicking on the redaction mark to set properties, you can use the context-sensitive Properties Bar to easily change the color of redaction marks.

To open the Properties Bar, choose View> Toolbars> Properties Bar or type CTRL-E.

With the redaction mark selected, you can easily change the mark to “no color”.


Applying the Redactions

Once you have marked up all the areas of the document to be cleaned, you need to apply the redactions to make final changes to your document.

  1. Click the Apply Redactions button on the Redaction toolbar.
  2. You’ll receive a stern warning. Redactions are permanent.

    Redaction Warning Dialog

  3. Acrobat will next ask if you would like to examine the document for metadata.

    Do you want to examine your document for metadata?
    You may skip this step depending on your workflow. Click the No button.

When you go to save the document, Acrobat will prompt you to rename the file.

While you may save over the original document, note that redactions are permanent and irrevocable. After you save over your original document, anything you marked is gone forever.

One Final Tip

If you regularly need to either redact or clean up documents, docking the Redaction toolbar can be convenient:

  1. Start Acrobat, but do not open any documents
  2. Choose View—>Toolbars—>Redaction
  3. Choose View—>Toolbars—>Dock Toolbars or Ctrl-F8 (Command-F8 on the Macintosh)
  4. Quit Acrobat

The Redaction toolbar will be docked for all future sessions.

9 Responses to Cleaning up Scanned Images

  1. Adonay hernandez says:

    I accidentally clicked No when it asks ” would you also like to examine your doc for additional doc information?” i checked the “always perform the selected action”…how do I revert this? or is the option redacted forever? thanks for the help.
    —- Rick’s Reply—
    You can use the Examine Document feature whenever needed.

  2. Lynn Crosbie says:

    Terrific!!! I was able to easily follow your directions and delete unwanted “sticky notes” from my pdf document.
    Thanks so much!

  3. John Deakin says:

    Redaction works as you suggest, but seems to leave a thin below, and to the left of the redaction. Any way to get rid of this, too?

  4. Biju says:

    thanks man that the thing i really need ,thanks for giving a nice tutorial tooo

  5. Steve Peacock says:

    If you have 50,000 documents that need holes ‘removed’? There must be an automated method that could work very much like Search and Remove that would prompt to remove similar images (ragged, larger, smaller holes), or all.

    • Rick Borstein says:

      ISI Toolbox is a plug-in that offers this feature. Otherwise, if the hole punches were all in the same place, you could write a little JavaScript action to place a redaction mark on all the pages, then bulk apply them.

  6. Steve Peacock says:

    Thanks Rick,

    I traced down what I thought would be a possible solution (for $60). for features and they give you a 15 day fly before you buy. Not having a lot of luck with the tech support (pre sales). First attempt resulted in a FLIPPED, MIRRORED image. Which they said to add FLIP along with using the HOLE REMOVE filters. It gets rid of the holes in as many documents as you identify including an entire folder’s worth, but the resulting file is very noticeably degraded. No response back on that surprise. It doesn’t seem to want to recognize Acrobat 10 generated files, either.

    Perhaps a more ingenious solution is at
    Solution includes the code and instructions. Have yet to venture that far though.

    It would be too easy to have them all the same size AND in the same place AND surrounded on all sides by white space. The scanner doesn’t help either. Because of the placement of the imaging light source, the holes look a bit like a crescent moon. Almost the entire hole is gone…but naaht quite.

    I’ll give isitoolbox a try this weekend.

    • Rick Borstein says:

      I can’t vouch for any third party products to remove holes and staple marks. Some of the higher end scanners do this at scan time in software.