Created attachment 137037 [details] problematic document SUMMARY Wobbly fonts observed in some pdf files when viewed in Okular (refer to the attached screenshot). Issue not present in Firefox pdf viewer or any other pdf viewer tested. STEPS TO REPRODUCE 1. Open attached pdf file in Okular 2. Open attached pdf file in Firefox 3. Compare OBSERVED RESULT Wobbly fonts (refer to the attached screenshot). EXPECTED RESULT Normal font rendering. SOFTWARE/OS VERSIONS Operating System: EndeavourOS KDE Plasma Version: 5.21.3 KDE Frameworks Version: 5.80.0 Qt Version: 5.15.2 Kernel Version: 5.11.8-arch1-1 OS Type: 64-bit Graphics Platform: X11 Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz Memory: 7.7 ГиБ of RAM Graphics Processor: Mesa Intel® UHD Graphics 620 ADDITIONAL INFORMATION Issue only observed with the attached file, which was composed of several pdf's all coming from the same source. All of those individual files had this issue present.
Created attachment 137038 [details] screenshot from Okular
I guess it's the poppler bug with Type 3 bitmap fonts. https://gitlab.freedesktop.org/poppler/poppler/-/issues/981 The fonts look bad (or even worse) in Chromium/Chrome embedded reader as well. These fonts are never intended to be used for reading from a screen. Please install cm-super package and regenerate the PDF with the modern LaTeX or print (as intended) then read it.
okular doesn't do any pdf rendering, so not okular's fault.