Alpha Blend

Problem

Blend two grayscale images with alpha blending.

For each pixel compute clamp(round(alpha * a + (1 - alpha) * b), 0, 255). Both images have the same shape and alpha is in [0, 1].

case 1

in: [[[0,100],[200,255]],[[100,200],[0,255]],0.5]

expected: [[50,150],[100,255]]

case 2

in: [[[10,20]],[[30,40]],1]

expected: [[10,20]]

case 3

in: [[[10,20]],[[30,40]],0]

expected: [[30,40]]

case 4

in: [[[10]],[[20]],0.25]

expected: [[18]]

Starter codePython

def alpha_blend(a, b, alpha):
    # Your code here
    pass

4 test cases · run your code against them in the editor