I have some figures I'm making that consist of tens of thousands of points. The PDF version of one of these figures is 1.1 MB, while the PNG version is 1.3 MB (both figures generated with the
matplotlib module of Python). I have dpi set to 400 for my PNG, overkill relative to the standard I know but I wanted to keep good resolution even if people zoom in on it.
Since the PDF version of the figure is slightly smaller, I figured that would be better to use as far as document load time is concerned. However, in my compiled document (compiled with pdflatex), the slightly larger PNG version of the figure appears virtually instantly, while it takes several seconds for the PDF version of the figure to load in the document.
Why is it that the smaller PDF figure takes so much longer to load?