rasterisation issue when using TikZ's doube line
Submitted by yas..@..hjz.de
Assigned to poppler-bugs
Description
Created attachment 97915 Problematic PDF
Okular (the KDE document viewer) does not correctly rasterise the attached PDF at certain (resolution-dependant) zoom levels. The problem is probably an anti-aliasing issue when two rectangles with slightly different width are drawn on top of each other to produce an equal sign. It seems to be a poppler issue as Evince shows a similar bug, though not as drastic as Okular. I checked a few other viewers, in particular Adobe Acrobat, and none of them showed the issue. The LaTeX code to produce the PDF can be found here [1]. My Okular bug report can be found here [2]. There you may also find a few screenshots which illustrate the problem. I can confirm the bug on my KUbuntu 14.04 netbook with poppler version 0.24.5. However, the bug isn't new, it is at least 2 years old.
[1] http://tex.stackexchange.com/questions/168071/tikz-double-line-rasterisation-issue [2] https://bugs.kde.org/show_bug.cgi?id=332900
Steps to Reproduce: Load the PDF and try different zoom levels. (The 'bad' zoom levels seem to dependent on the screen resolution.) On my netbook (1024x600), the issue appears below 200%.
Attachment 97915, "Problematic PDF":
rast.pdf