Clipping input data to the valid range for imshow with RGB data ([0..1] for floats or [0..255] for integers)

Question

I tried to run the graph cut algorithm for a slice of an MRI after converting it into PNG format. I keep encountering the following problem:

Clipping input data to the valid range for imshow with RGB data ([0..1] for floats or [0..255] for integers).

This is even after setting vmin and vmax as follows:

plt.imshow(out,vmin=0,vmax=255)

Answer 1

Cast the image to np.uint8 after scaling [0, 255] range will dismiss this warning. It seems like a feature in matplotlib, as discussed in this issue.

plt.imshow((out * 255).astype(np.uint8))

Answer 2

If you want to show it, you can use img/255. I haven't figured out what's going on.

Or

np.array(img,np.int32)

Answer 3

Instead of plt.imshow(out), use plt.imshow(out.astype('uint8')). That's it!