Scanned PDF is not displayed properly in DTTG

I have a couple of PDF files with scanned vintage books downloaded from the Internet. They display normally in Devothink on my Mac. However, when I try to browse them on my iPad in DTTG most of the pages are just blurry (not readable at all). I observed exactly the same behaviour also on my iPhone. Only some pages with little content display well. The files are displayed properly when I open them in Adobe Acrobat on the same iPad, i.e., the files in Devonthink database are not corrupted. Closing and reopening the application does not make any change.
What could be the problem?

the files in Devonthink database are not corrupted.

The odds of files being corrupted in a way that would visually distort the appearance is slim.

How large are the files and how many pages?

The files vary in size but they are rather compact. The one I tried to use last time is 12,5 MB/230 pages (common book size). Another one is 14,5 MB/133 pages.

Being rather compact with that number of pages suggests a high level of compression. Please ZIP one of the problematic PDFs, then start a support ticket, and send the ZIP along. Thanks.


This could be the same issue I’ve reported related to not showing PDF text in some PDF got from It seems PSPDFkit has resolved it in his own application but not in the SDK.

As a temporary workaround, @pvandas, you can install PDF Viewer from PSPDFkit (it is free) and use it from DTTG Files integrated file system. Don’t forget to go back into DTTG once you finish with PDF Viewer if you have modified the PDF.

It’s possible indeed. I have an issue filed on this as I reproduced the behavior here.