How To CLEAN Your Scans

Every once in a while you come across some scans that are polluted by smears, streaks, dots (black snow), or extraneous markings, any of which make the scans look bad, sometimes even making them nearly unreadable. Sometimes the scans are printed to strangely-sized documents, nothing like the standard paper you print on, and sometimes the scans are skewed, sitting at a strange angle to the page.
This page discusses various methods for cleaning up and fixing these scans so they will look better, almost new. We know that not everyone has the same software, so we'll put here whatever solutions you send us or post to the forum. Well, we'll TRY to get them all, but no promises. After all, this is another volunteer gig.
You can scroll down the page, or use one of these links to go directly to the section you need:
- Getting Rid of Extraneous Smears, Marks, or "Snow"
- Correcting a Skewed Document
- Fixing Documents Printed to Oddball Sizes
- Fixing Margins
- (Re)Inverting Colors
- Removing Background Colors (or Grey Background)
The Starting Point
We're starting with some sort of imperfect PDF document. How you fix it depends on what's wrong with it. We'll try to discuss each of the problems, and at least one way to fix it, in the following paragraphs.
Getting Rid of Extraneous Marks, Smears, or "Snow"
If your document has markings on it you want to get rid of, there are several ways to do that.
One of the most straightforward ways to fix this is:
a. Save the document as an image file, either JPG or TIF
b. Use a paint program to paint over the extraneous marks with white
c. Print the cleaned-up document to a new PDF
We explain each of these steps in more detail next.
a. Save The Document As An Image File
Whichever PDF program you are using should have the capability to EXPORT the current document as an image file. Generally, this will be under the FILE menu, and may be called EXPORT or EXPORT AS. If given a choice, select JPG or TIFF (TIF). You will probably need to select the folder or directory to which to save it.
UPDATE: Feedback from group members tells us some of the software discussed on our PDF Tools page have this capability and some don't. As of this writing, we know that Adobe Acrobat Standard and Pro (not Reader) and PDFill have this capability.
b. Use a Paint Program To Paint Over The Extraneous Marks.
If you do not have a paint program, you can download Picasa for free. Read about other free paint programs here. (Thanks to Marc for the link.)
Simply open up the converted image program from step a. above, and set your "brush" to white, the same as your background color, and use it to "paint out" any extraneous marks.
You can change the size of your brush, large for big area painting, small for fine work. You can also zoom in for fine work to allow yourself a close-up view of the details.
You can also change your brush color to black and add any other markings you want to appear. You can use the text tool to add annotations to the image, if you wish.
Once you have finished painting out all marks that you do not want to appear in your final version, save the image file. It's okay to overwrite the original.
c. Print the Cleaned-up Document as a New PDF
Your PDF program should be installed on your computer as a printer driver. Once your document is cleaned up Print it (File/Print) and select whatever PDF driver you have as your "printer."
Unless you have a good reason to keep the old (dirty) PDF file, it's okay to overwrite the old one with the new one. However, since printing to PDF usually only works one page at a time, and since the protocol for scanned charts is to put all the pages into a single PDF file, you will probably want to save your image as an individual file, and combine the individual files into a single PDF file later on. (See the "Customary Protocols" page for more details on this.)
If you have Adobe Acrobat Pro, try this:
a. Open the PDF in Acrobat
b. Use the ADD TEXT BOX tool to draw a white box over anything you want to block out - this can be short and wide, long and tall, draw as many as you need. As long as your background is white, this box will totally disappear, taking the smudges and marks it covers with it.
c. When you're done, do not SAVE the document, but rather PRINT it to a new PDF.
I did this with an original scan of an 8-page score. The original scan was 4.1MB, but the newly saved (and clean) file was only 1.4MB.
Almost any art program will do for a SIMPLE clean-up. In fact, Microsoft may still include "MSPaint" with its operating systems. However, for specific features like "clone", I use an old chestnut, Paint Shop Pro, by JASC software. PSP (I use Version 9.01, published in 2004) has been around since 1989, and was an early precursor of Photo Shop. It was such a strong competitor that in 2006, JASC was bought by Corel. The program is still being upgraded yearly, but I personally prefer the old version. I expect that one of these days it will no longer work with the current operating system.
The newest version is "Paint Shop Photo Pro X5 Ultimate" ($60). A free-trial version is available here:
There is also an "ultimate" version ($100), but that only adds "features" that I don't need.
I grew up with PSP, and am so comfortable with it that I can run rings around Photo Shop for all of the PRE-PDF work (straightening, cleaning, dodging and burning, manipulating, as well as extras such as merging an entire clean title block from one page onto another, etc etc etc). Once I have all of that done, I then use Adobe Acrobat Pro to convert the images to PDFs. (I use Adobe because the school where I teach has a site license, but there are a number of free alternatives - - check CNET.COM)
There's also an excellent freebie, Picasa, available at picasa.google.com/ (they have recently releaed version 3.9). I don't use it myself, but I have heard glowing reports from some folks I respect.
Correcting a Skewed Document
If your document is not perfectly straight on the page, here are some ways you can straighten it out. (Check Arnie's writeup on PaintShop Pro, above. More information to come here as we receive it.) ...
Fixing Documents Printed To Oddball Sizes
Some scanners produce a PDF document sized exactly to the dimensions of the source document. I have an entire set of scans of which 90% are of sizes much different than the standard-sized sheets of paper I print to.
Here's how to convert these documents so they will print properly on standard-sized paper. We are bearing in mind here that the standard-sized paper in the U.S. (8 1/2" x 11") is a bit different than standard-sized paper in Europe and Asia, but these instructions should apply in any case.
1. Open the PDF file in Adobe Acrobat or the PDF viewer/printer of your choice.
2. Print each page as a new PDF file to your standard size paper. (You will need to have a PDF printer installed for this. Our page on PDF printing is here.)
Once you have your document re-printed to a standard size, you might consider whether you need to do additional repairs, as listed above.
Fixing Margins
Sometimes you have scans with the print too close to the margins of the page, such that when you print them, the edges of the music is cut off, or is otherwise difficult to read.
The easiest way to add margins (Thanks to Clark G) is to simply print the part at 94%. This will leave room for the margins. If you want PDFs with the margins, do the same, but print to pdf. If you don't have software to do this, you can use the free PDFill PDF Tools. Don't feel that you have to buy the upgrade. The free version does many things that you'll need on a daily basis. You can always upgrade later. Macs have a built in option to do this.
Inverting Colors
Occasionally, you'll get a scan with the colors reversed. That is, with white print on a black background. Not only is this irritating and hard to read, but it also uses a ton of ink or toner if you try to print it. Here are some ways to re-invert your colors so you'll have the standard black print on a white background scan.
Using PAPERPORT, open the file in image view. Select the page to change, then in page view click on Invert Colors. Crop the final page and you're done. (Thanks to Jerry J)
To use Adobe PHOTOSHOP: Right click on the PDF, open with Photoshop in greyscale; flatten the pages, clean it up a bit with the eraser, if necessary. Then use Ctrl-Shift-i inverse, save as PDF (ctrl-shift-s); I used "in smallest file size." Insert the saved pages into the original PDF. Then optimize and crop the PDF in Acrobat. (Thanks to Claudia H)
Removing Background Colors (or Grey Background)
Sometimes, you will receive a PDF scanned in color, or in black and white, in which the background is shaded, making it difficult to read and using up more toner/ink than you need to when you print.
To use Adobe PHOTOSHOP: First, open the PDF file in Photoshop. Next, use the THRESHOLD adjustment to remove the background shading. (To get to this command in Photoshop CS6, go to Image>Adjustments>Threshold.) Use the slider and the preview mode to adjust the image so its appearance is as you like it. Finally, save the image, either as a new file, or overwriting the old one. (From David M) Note: This will probably also work in Photoshop Elements, but hasn't yet been tested.
(We need directions for how to do this in other PDF packages, if anyone knows how.)
More to come as we receive well researched and well-written submissions.

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