Blurry text in pdf viewer

I downloaded Collabora Office v. to my Android tablet, hoping to use it as an alternative to WPS. Unfortunately, the pdf viewer doesn’t appear to be all that good. The text in pdf files is blurry. The same files viewed in WPS or Firefox are crystal clear and razor sharp. So, it isn’t the files.
I really just want to know what I can expect…
Is there a setting in Collabora that I can change to improve the text resolution on the screen for these files?
Is it something to do with the Android settings?
Is it a bug that could be fixed in future?
Is the pdf viewer a bit of an afterthought with no plans to improve it?

Hello @hught,

Thank you for reaching out and welcome to the Collabora community! We’re sorry to hear that you’re experiencing issues with the PDF viewer in Collabora Office on your Android tablet.

Regarding your concerns:

  1. Settings in Collabora: Currently, Collabora Office doesn’t have specific settings to adjust text resolution within the PDF viewer. The quality you’re seeing is likely a result of the built-in PDF rendering engine.
  2. Android Settings: It’s unlikely that Android settings are causing this issue, as you’ve mentioned that other apps like WPS and Firefox display the PDFs clearly. However, you might want to check if there’s any system-wide display enhancement setting that could impact rendering, though this is a long shot.
  3. Potential Bug: This could be a rendering bug or limitation within the current version of the PDF viewer in Collabora Office. Such issues can be addressed in future updates if reported properly.
  4. Future Improvements: While Collabora Office is primarily focused on document editing, feedback from users like you is essential. If the PDF viewer doesn’t meet your expectations, reporting this issue will highlight the need for improvement.

I will submit a bug report through the Collabora Online GitHub repository.

Meanwhile, it would be very helpful for our development team if you could provide the following information:

  • The device model you are using.
  • The screen resolution of your device.

We appreciate your understanding and patience. Your feedback is invaluable If there’s anything else we can assist with or if you have further questions, please let us know.

@hught please feel free to add your comments in GH issue PDF Viewer Renders Blurry Text on Android Tablet (v23.05.5.2) · Issue #9462 · CollaboraOnline/online · GitHub :slight_smile:

@darshan Thanks, that’s very helpful and provides useful context.

The exact device I am using is the Alldocube iPlay 50 Mini and the screen resolution is 1920 x 1200.

I don’t know if Collabora uses the Android PdfRenderer class to view pdfs but this article might help or give some clues to what is going on:

We use a built in PDF-ium; and we render at a fixed resolution and then interpolate up and down - which causes your issue. Its possible to improve that of course - if you’d like some code pointers do get in touch =)

Well, it’s refreshing to get an answer that goes right to the root of the issue. Unfortunately, I’m not sure that I would have the skills to do anything about it. Rendering this way seems to have trade-offs between speed, memory use and resolution (at least). So, it looks like I’m stuck with it unless someone decides the answer to my fourth question is no.

Thank you, @hught, Improving the PDF viewer would be good but for now it’s not a priority, I think. Nevertheless I will try to keep tabs on the github issue.