Convert RGB to black OR white

Question

How would I take an RGB image in Python and convert it to black OR white? Not grayscale, I want each pixel to be either fully black (0, 0, 0) or fully white (255, 255, 255).

Answer 1

And you can use colorsys (in the standard library) to convert rgb to hls and use the lightness value to determine black/white:

import colorsys
# convert rgb values from 0-255 to %
r = 120/255.0
g = 29/255.0
b = 200/255.0
h, l, s = colorsys.rgb_to_hls(r, g, b)
if l >= .5:
    # color is lighter
    result_rgb = (255, 255, 255)
elif l < .5:
    # color is darker
    result_rgb = (0,0,0)