matplotlib/matplotlib — pull request #1291 by mgiuca-google (2012-09-21 00:08:13+00:00)
Title: Fix image comparison

Fixes the compare_image RMS calculation algorithm, so that it computes the RMS of the difference between corresponding pixels, as opposed to the RMS of the histograms between the two images.

See discussion on [Issue 1287](https://github.com/matplotlib/matplotlib/issues/1287).