View Full Version : PDF document editing

November 7th, 2017, 09:15 AM
Hello Folks,

Recently I have come across some really grayish and shadow-filled
PDF documents. Any suggestions on how to remove the dark areas and
finish with a bright and glowing document still in PDF format.

Thank you

ziloo :mrgreen:

November 7th, 2017, 09:41 AM
Try this one:


Lately I've been getting into Portable Apps for convenience, ease-of-use and the simple fact that they don't add bloat to the Registry.

November 7th, 2017, 09:43 AM
use the redaction tools to fill the crazy area with white.

November 7th, 2017, 09:45 AM
If you're of a Linux inclination, remember that LibreOffice Draw has been able to edit PDFs for a couple of years now.

If you want to break a document down into essentials and change them in a CLI environment, there's also pdftk. There's a GUI frontend for it called PDFChain.

November 7th, 2017, 09:46 AM
Arrrrrraaaag. I hate messy unreadable PDF files.

However to properly correct them you would need the source images.

Most PDF files compress images with lossy JPG compression. There are tools that will extract PDF files to individual pages. Then you can use a tool like ImageMagick (mogrify) to adjust things like skew, cropping, highlight, midtone, saturation, contrast, and so on. But when you rebuild the PDF you will loose some image quality as it gets re-compressed. Now that I think of it, I believe ImageMagick itself can extract PDF files.

You will also need to re-run the images through an OCR tool, if you want searchability.

So if the images in the PDF have enough resolution, then it may clean up. But if they are really that bad to start with, I'm not sure I would hold out much hope.

November 7th, 2017, 09:46 AM
It depends on how the PDF was made and what tools you have. If the PDF is a bunch of scanned images and you have Adobe Acrobat Pro, you can use the "Optimize Scanned PDF" option (under View / Tools / Document Processing) to clean things up. If you prefer to clean up bitmap images in an external tool you can use "Export All Images" instead to make a bunch of individual files, use your bitmap cleanup application of choice (preferably one that has a batch or command-line mode), then make a new PDF from the cleaned-up images.