FPN Top-Down Add

Problem

Add a top-down feature map to a lateral feature map elementwise.

Both inputs are H x W x C grids of the same shape; return the per-pixel, per-channel sum rounded to 4 decimal places.

case 1

in: [[[[1,2]]],[[[3,4]]]]

expected: [[[4,6]]]

case 2

in: [[[[1,1],[2,2]]],[[[3,3],[4,4]]]]

expected: [[[4,4],[6,6]]]

case 3

in: [[[[5]]],[[[7]]]]

expected: [[[12]]]

Starter codePython

def top_down_add(up, lateral):
    # Your code here
    pass

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