Bug report

Bug summary

matplotlib.pyplot.imshow definition alpha compositing is incorrect, references#3343.

Code for reproduction

frommatplotlibimportpyplotaspltplt.figure(figsize=(8,8))RGBA=plt.imread('RGB_Droplet.png')plt.imshow(RGBA)plt.show()

Actual outcome

Expected outcome

Composited in The Foundry Nuke:

The images used are available here:

• RGB_Droplet.png
• RGB_Droplet_Over_White_Reference.png

Matplotlib version

• Operating system:macOS
• Matplotlib version:'2.1.0'
• Matplotlib backend (print(matplotlib.get_backend())):'module://ipykernel.pylab.backend_inline'
• Python version:'2.7.13 |Continuum Analytics, Inc.| (default, Dec 20 2016, 23:05:08) \n[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)]'
• Jupyter version (if applicable):notebook 5.0.0 py27_0