Bitmap aliasing and coordinates precision
Submitted by Jorge Hernández Valiñani
Assigned to poppler-bugs
Created attachment 57904 PDF with bitmap aliasing and object placement inaccuracies.
(Note: I only know how to install Macports version, today 0.18.2; I do not know if this happens in a later version)
The following PDF has two problems when rendered with
pdftoppm -r 159 -f 27 -l 27 -tiff sample.pdf > output.tiff
Either the rendered bitmaps have aliasing problems or the output has some horizontal lines missing.
The placement of one bitmap layer (top black ink) with respect to the other one (bottom color) is inaccurate. As a result color seems displaced.
See embedded "output(pdftoppm).jpg" pointing out areas where this happens.
pdftocairo provides no bitmap antialias whatsoever (which I would consider a bug too), so it makes it difficult to see whether the two bugs above happen or not too.
None of these issues happen when rendering with Acrobat X (i.e. Acrobat renders this PDF flawlessly).
Attachment 57904, "PDF with bitmap aliasing and object placement inaccuracies.":