Functions to determine brightness of rgb/hex colours

colour_brightness.py

# Base on http://zoltanb.co.uk/how-to-calculate-the-perceived-brightness-of-a-colour/

import math, struct


def rgb_bright(r, g, b):
    return math.sqrt(r*r*0.241 + g*g*0.691 + r*r*0.068)
  
def hex_bright(hex):
    rgb_tuple = struct.unpack('BBB', hex.decode('hex'))
    return rgb_bright(rgb_tuple[0], rgb_tuple[1], rgb_tuple[2])
    
def check(hex_arr):
    result = []
    for hex in hex_arr:
        result.append(hex_bright(hex))
        print hex + ' -> ' + str(hex_bright(hex))
    return result
    

# these are the shades of green
# check(['64B21A', '7ABA40', '9DC974', 'B8D59F', 'D1E0C3'])

# these are ajiths colours
# check(['c0392b', '1abc9c', 'f1c40f', '3498db', '2ecc71'])

# these are amandas colours
# check(['EC008C', '009999', 'F7941D', '00AEEF', '0D9B39'])

# my revisions
# check(['E02F98', '2F9C9C', 'E5911B', '009ED9', '0D9E3A'])