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Khushi TyagiChristian Clausspre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
a10a1ce2cd ty: un-ignore invalid-type-form (#15387)
* ty: un-ignore invalid-type-form

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Co-authored-by: Christian Clauss <cclauss@me.com>

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Christian Clauss <cclauss@me.com>
2026-09-21 12:30:25 +02:00

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846 B
Python

"""
Changing contrast with PIL
This algorithm is used in
https://noivce.pythonanywhere.com/ Python web app.
psf/black: True
ruff : True
"""
from PIL import Image
def change_contrast(img: Image.Image, level: int) -> Image.Image:
"""
Function to change contrast
"""
factor = (259 * (level + 255)) / (255 * (259 - level))
def contrast(c: int) -> int:
"""
Fundamental Transformation/Operation that'll be performed on
every bit.
"""
return int(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")