image merge

from PIL import Image

def avTwo(t1, t2):
    return tuple([(a+b)/2 for a, b in [i for i in zip(t1, t2)]])

file1 = 'a.png'
file2 = 'b.png'
dimensions = (1920,1080)

pic1 = Image.open(file1).resize(dimensions)
pic2 = Image.open(file2).resize(dimensions)
p1dat = pic1.getdata()
p2dat = pic2.getdata()
p1dat = list(p1dat)
p2dat = list(p2dat)

total = [avTwo(a, b) for a, b in zip(p1dat, p2dat)]

img = Image.new('RGB', dimensions, "white")
img.putdata(total)
img.show()