matplotlib/matplotlib — Issue #674: alpha does not work in imshow() with 'none' as interp
Author: WeatherGod
Created: 2012-01-14 23:32:52+00:00
State: open

In both master and v1.1.x, if one uses the new 'none' interpolation on a backend that does support alpha blending, the 'alpha' value appears to be completely ignored. If one sets interpolation='nearest', then everything appears correct (alpha-blending-wise, that is).

The best I can figure out is that the _draw_unsampled_image() calls 'im.reset_matrix()', but the other approaches do not. This might be a red herring, though.