Hardcoded DPI settings in PDF and Cairo backends


I'm currently doing my diploma thesis with matplotlib plots and I have a
problem there. Many of the plots include an imshow(), which is completly
blurred when I do a savefig() to PDF. The problem seems to be the
hardcoded DPI settings in the PDF and Cairo backends (dpi=72), which is
far too low for a printing quality image. When looking for the source of
this setting, I found
which does not make any sense to me. Why was the kwargs readout
disabled, even if the default setting was already 72dpi? If I
explicitely do a savefig(file, dpi=XX), it could be assumed that I
REALLY WANT a DPI setting of XX. And if I don't supply any dpi
parameter, the default of 72 will be used.

Best regards,