Created attachment 128403 [details] screenshot at 150% zoom, and scaled to fit the document When a normal sized (DIN A4) document is resized to fit the window vertically, objects within a document are misaligned, causing certain documents such as music sheets to render unreadable. STEPS TO REPRODUCE 1. Open any DIN-A4 document with high detailed elements such as a music sheet. 2. Fit to window vertically 3. Observe the details (notes in a music sheet) be misaligned, rendering the sheet unreadable OBSERVED RESULT Elements of the PDF are misaligned, causing unreadable documents. EXPECTED RESULT Elements should be accurately aligned. SOFTWARE/OS VERSIONS Linux/KDE Plasma: (K)Ubuntu 18.04 and 20.04 tested KDE Plasma Version: 5.18 KDE Frameworks Version: 5.68.0 Qt Version: 5.12.8 ADDITIONAL INFORMATION Attached screenshot at 150% zoom, and scaled to fit the document
Can you share a sample PDF file for testing? BTW Okular does not produce the image itself (but its core library, poppler does. Can you try if Evince (also PDF-based) has the same bug? If so, this should be reported against poppler. Thanks in advance for your answers.
Created attachment 128405 [details] Screenshot comparing Okular, Evince and Zathura
I had tried reading these sheets with Evince and Zathura, both using poppler as backend, and none of them seem to have the same issue when scaling down. I use okular more comfortably due to the interface, but I am forced to switch to Zathura when this issue arises. I have attached a screenshot of the three, at matching document zoom (notice that evince and okular do not show the same document size on screen when the same zoom % is selected in the app, so different zooms levels were selected until both rendered same pixel sizes 1:1 on screen). Screenshots have not been scaled.
I just sent the PDF document from which I took the screenshots privately by e-mail, for debugging purposes. Unfortunately I cannot legally share the document here publicly due to copyright issues. Please do not redistribute the document. However, you can check the same bug on numerous open documents: e.g. , I can see certain notes swapped when scaling down on the 2nd page of: https://files.musopen.org/media/9c0cee4b-0287-439e-850a-396f66b35ac9.pdf?filename=Adagio%20in%20G%20minor%20-%20Complete%20Score%20%28Keyboard%20and%20Violin%29.pdf
Looks like a poppler-qt rendering bug (qpdfview shows an identical image).
As a workaround, you may try https://invent.kde.org/kde/okular/-/merge_requests/112 which selects a different render backend. (Apologies for still not having found the time to actually finish that).