Python/digital_image_processing/change_contrast.py

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"""
Changing contrast with PIL
This algorithm is used in
https://noivce.pythonanywhere.com/ python web app.
python/black: True
flake8 : True
"""
from PIL import Image
def change_contrast(img: Image, level: float) -> Image:
"""
Function to change contrast
"""
factor = (259 * (level + 255)) / (255 * (259 - level))
def contrast(c: int) -> float:
"""
Fundamental Transformation/Operation that'll be performed on
every bit.
"""
return 128 + factor * (c - 128)
return img.point(contrast)
if __name__ == "__main__":
# Load image
with Image.open("image_data/lena.jpg") as img:
# Change contrast to 170
cont_img = change_contrast(img, 170)
cont_img.save("image_data/lena_high_contrast.png", format="png")