Python, Display openCv image in Tkinter in Label
I think the problem is that the greyscale values given by rgb2gray(io.imread("asd.png")) are between 0 and 1 while PIL expects values between 0 and 255, so the result of Image.fromarray(image) is a black square since all values are smaller than 1.
Therefore image2 = Image.fromarray(image*255) should give the expected image.