Case insensitive check for PNG extension

mdboom · mdboom · commit cd0e7e07024f · 2016-02-17T09:47:57.000-05:00
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
@@ -1161,7 +1161,8 @@ def imsave(fname, arr, vmin=None, vmax=None, cmap=None, format=None,
 
     # Fast path for saving to PNG
     if (format == 'png' or format is None or
-        isinstance(fname, six.string_types) and fname.endswith('.png')):
+        isinstance(fname, six.string_types) and
+        fname.lower().endswith('.png')):
         image = AxesImage(None, cmap=cmap, origin=origin)
         image.set_data(arr)
         image.set_clim(vmin, vmax)
