Running-Average Background

Problem

Update a running-average background model with a new frame.

new_background = alpha * background + (1 - alpha) * frame per pixel, rounded to 4 decimal places. alpha is in [0, 1].

Hint

alpha weights the old background; 1 - alpha weights the new frame.

case 1

in: [[[0,10]],[[10,0]],0.9]

expected: [[1,9]]

case 2

in: [[[0,10]],[[10,0]],1]

expected: [[0,10]]

case 3

in: [[[0,10]],[[10,0]],0]

expected: [[10,0]]

case 4

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

expected: [[50,50],[150,50]]

Starter codePython

def update_background(background, frame, alpha):
    # Your code here
    pass

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