Created attachment 88175 [details] rendering artifacts with antialias enabled When the option "Graphics Antialias" is enabled some PDFs show rendering artifacts. Please see the attached pictures for a comparison. The artifacts go away if the option is disabled (however that mean poor general rendering quality). Other readers not based on poppler are not affected (e.g. muPDF).
Created attachment 88176 [details] correct rendering with antialias disabled
Created attachment 88177 [details] original pdf
In case it is not clear, the problem is in the slight darker outline that can be seen at the end of the blurred region. It should be easy to spot the problem if you open the test pdf in okular first and then with mupdf
This is an issue with poppler the rendering library we use for pdf files. Please report the bug upstream at https://bugs.freedesktop.org/ Thanks for caring about okular :)
upstream bug: https://bugs.freedesktop.org/show_bug.cgi?id=82391