Bug report

Bug summary

savefig() with type='png' produces different image sizes, depending on the dpi argument when calling figure().

Code for reproduction

from pylab import *
%matplotlib tk

plt.figure(figsize=(1,1),dpi=100)
plt.savefig("100-300dpi.png",type="png",dpi=300)

plt.figure(figsize=(1,1),dpi=96) #96 is my screen DPI
plt.savefig("96-300dpi.png",type="png",dpi=300)

Actual outcome

100-300dpi.png is 654x300 pixels.
96-300dpi.png is 681x300 pixels.

Expected outcome

I would expect both to come out at 300x300 pixels, or at least equal size.

Matplotlib version

• Matplotlib 2.0.0
• Python 2.7.13
• IPython 5.1.0
• Jupyter Version: 4.4.1
• Platform: Linux