How can I improve readability of a low-quality .pdf file?

January 15, 2007 8:45 PM

I'm attempting to transcribe some scanned documents. The quality of the .pdf files is low. Is there a way to play around with the images in order to help me make out the mangled words?

I've got the basic Mac software, plus Photoshop. I haven't got money to spend on extras. Any hot tips and tricks?

posted by moira to computers & internet (7 comments total)

try opening up the pdf is photoshop and using the "sharpen" filter. I did this today for something and it worked wonders.
posted by unexpected at 8:47 PM on January 15, 2007

Rescan the documents. An image shrunk to a certain quality level (where it is unreadable) cannot generally have quality "added" to it to restore readability.
posted by Blazecock Pileon at 9:11 PM on January 15, 2007

Rescan the documents. An image shrunk to a certain quality level (where it is unreadable) cannot generally have quality "added" to it to restore readability.

I'm guessing if moira had the documents it'd be easier to transcribe them from print rather than scanning them in.

Sometimes you can actually see things better if they are smaller rather than larger. Try moving away from the screen. Sometimes your eyes can "figure out" what the words are if you don't look at them too carefully.

Also, it might be useful to define "low quality." Are they just really low resolution? Are they muddy or too light/dark, not enough contrast? Each of these problems can probably be alleviated with different varieties of Photoshop techniques, I imagine.
posted by Deathalicious at 9:34 PM on January 15, 2007

To clarify, the text is readable with the exception of a few words. I'm afraid I don't have the original documents to work with. The issue is with low resolution scans of poor print quality text (very old documents).
posted by moira at 9:40 PM on January 15, 2007

You may get some milage out of Sharpen, Levels and (maybe) Threshold in Photoshop. Play with the settings and see what you can do. Check the different color channels to see if one of them is easier to read than another. Without a sample file I can't give much more specific advice.
posted by wemayfreeze at 9:53 PM on January 15, 2007

Adjusting the image "contrast" in Photoshop may yield results - particularly if you are having an issue with dark print blending unacceptably with a dark background.
posted by gaiamark at 3:26 AM on January 16, 2007

Levels did the trick; thanks. I'll keep all of these in mind as I work on more documents.
posted by moira at 8:53 PM on January 16, 2007