Created attachment 125444 [details] screen photograph of sheet music with thick and thin staff lines SUMMARY sheet music staff lines are uneven STEPS TO REPRODUCE 1. Load a sheet music pdf file prepared by program Smartscore X2 2. save it as a pdf 600 dpi with any of three converters Scansoft PDF Create,Gaaiho PDF, PDF Creator 3. When I open any of these files in Okular The lines in the music staffs are thicker and thinner, the thick lines are difficult for musicians to read as they oclude some notes and look line music staff ends so that the interpretation of the notes are difficult These thick and thin lines occur on 7 of my other pdf readers but do not happen in Smartscore x2 and do not occur in PDF Studio, and when these pdf's are printed on a epson wf3640 the lines are all the same width and look clean and sharp. OBSERVED RESULT. When I use Okular and several other pdf readers these thick and thin staff lines show up on my 24, 25, 23" monitors operating HDMI 1029 1940, If I zoom in to 200+ percent, the staff lines look like two parrallel lines on the screen instead of the single staff line that they should be. I create the sheet music by scanning it at 400 dpi into Smartscore x2, it does OCR and I edit the sheet music leaving only the singer's line, then I save it as an enf file for further editing, and save it as a pdf file for display to play the music. The displays on Windows 10 and Raspberry Pi have the thick and thin lines in the music staff. I recently downloaded PDF Studio and it displays even lines. I would prefer to continue to use Okular on my RPI's as it is stable and has a good command set and nice display EXPECTED RESULT SOFTWARE/OS VERSIONS Windows: Windows 10 macOS: Linux/KDE Plasma: Raspian for RPI 3 and RPI 4 (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION my okular version is 1.3.2
When I change the zoom level from, for example, 92.6% to 93.7%, the thicker lines change positions. they are still there it is just that where they were lines for thick lines for nones e,g,b;thin line for d,f, thy will change to where the thin lines will be: e thin, g thick, b thick, d thick, f thick. I thought these might be interferrence patterns with the scan lines on the monitor, but changing resolutions of the monitor does not help clear it up and changing resolution of the pdf converter does not help and changing resolution of the epson v550 scanner does not help.
Can you attach a sample PDF file?
Created attachment 125533 [details] screen photograph of sheet music with thick and thin staff lines This is a set of sheet music, that we display on 24" monitors, two pages wide. This file shows the thick and thin lines in the staff. The next file I'll submit shows a potential work around where the pdf file is opened and printer to file using the MS xps printer. That resulting file shows satisfactory staff lines on my PC xps viewer. When I transfer these files to my RPI running raspian, I can view the xps file in evince with satisfactory staff lines just line on the pc, but Okular will not open the same xps file. I will include the xps file in the next addition to the bug report as I don't see how to send two files here. Thank you for your help. This represents a work around, but I would prefer to view my music in Okular as previously stated.
Created attachment 125534 [details] screen photograph of sheet music with uniform staff lines This file shows the same sheet music printed to file on my ms10 laptop to xpf printer. The uneven lines are abated and show a satisfactory improvement over the pdf files printed by the same program and file converters from Smartscore X2 .enf files through three different pdf file converters. When displayed on PC or on RPI on hdmi 24, 25,23" monitors, dell, aoc, hp brands they all show the uneven staff lines that make reading difficult. But, while evince reads these xpf files on the RPI, Okular does not. It stops with the message, " Could not open file///path/set list 2 xpf printer.oxps
Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information as soon as possible and set the bug status as REPORTED. Due to regular bug tracker maintenance, if the bug is still in NEEDSINFO status with no change in 30 days the bug will be closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging If you have already provided the requested information, please mark the bug as REPORTED so that the KDE team knows that the bug is ready to be confirmed. Thank you for helping us make KDE software even better for everyone!
Requested PDF was added with comment 3; changing status for inspection.
Changing status.
Hi John, are you able to compile your own Okular and try https://invent.kde.org/kde/okular/merge_requests/112 ? That patch allows to make Okular use the Qt rendering backend, which fixes the thin-line rendering for me. Beware that this alternative backend is much less mature than the default one, and you may observe other rendering problems. However, your sheet music example looks very good to me.
I'm having the exact same problem than here and for https://bugs.kde.org/show_bug.cgi?id=377493, I'm attaching the examples for my exact case. The music sheet I'm joining seems to be a transcript of music I don't own, and I don't have any permission from the author either so here is the link to the video that links to the said file (https://www.youtube.com/watch?v=HL4dLPhsFi0). As you can see in the comparison photos (librewolf/firefox on the left, okular on the right), it is very difficult to distinguish a note that's on a line and above the line in some cases (the document is at fault too, but it is especially troubling with okular). The problem arises as long as I try to arrange a page on half my monitor, that is 1600 x 600 aspect ratio, and disappears if I try to view the document with a bigger zoom. I could gladly test the proposed patch, but it seems unable to be merged, so I'll leave it to you until there's a new update on this. Thanks for your hard work !
Created attachment 154057 [details] Comparison between librewolf and okular for displaying sheet music