python-gallery/onlylegs/utils/contrast.py
2023-04-12 16:58:13 +00:00

26 lines
763 B
Python

"""
Calculate the contrast between two colors
"""
def contrast(background, light, dark, threshold=0.179):
"""
background: tuple of (r, g, b) values
light: color to use if the background is light
dark: color to use if the background is dark
threshold: the threshold to use for determining lightness, the default is w3 recommended
"""
red = background[0]
green = background[1]
blue = background[2]
# Calculate contrast
uicolors = [red / 255, green / 255, blue / 255]
cont = [
col / 12.92 if col <= 0.03928 else ((col + 0.055) / 1.055) ** 2.4
for col in uicolors
]
lightness = (0.2126 * cont[0]) + (0.7152 * cont[1]) + (0.0722 * cont[2])
return light if lightness > threshold else dark