alien-glow

#!/usr/bin/env python

from PIL import Image, ImageFilter
import argparse

def add_alien_glow(input_path, output_path, glow_radius=2, glow_intensity=105):
    # Open image with transparency
    img = Image.open(input_path).convert("RGBA")

    # Extract alpha channel (transparency)
    alpha = img.split()[3]

    # Create a white base for the glow
    white_glow = Image.new("RGBA", img.size, (255, 255, 255, 0))
    glow_mask = alpha

    # Expand the alpha to create the "glow radius"
    for _ in range(glow_radius):
        glow_mask = glow_mask.filter(ImageFilter.MaxFilter(3))

    # Blur for a softer look
    glow_mask = glow_mask.filter(ImageFilter.GaussianBlur(glow_radius))

    # Put white into the glow area
    # Create a lookup table for the glow intensity
    # This resolves the "Operator > not supported" error with ImagePointTransform
    lut = [min(255, int(p * (glow_intensity / 255.0))) for p in range(256)]
    white_glow.putalpha(glow_mask.point(lut))

    # Composite the glow behind the original image
    final_img = Image.alpha_composite(white_glow, img)

    final_img.save(output_path, "PNG")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Add an alien glow effect to an image.")
    parser.add_argument("input_path", type=str, help="Path to the input image file (e.g., input.png).")
    parser.add_argument("output_path", type=str, help="Path to save the output image file (e.g., output_glow.png).")
    parser.add_argument("-r", "--glow_radius", type=int, default=3, help="Radius of the glow effect. Default is 25.")
    parser.add_argument("-i", "--glow_intensity", type=int, default=125, help="Intensity of the glow effect (0-255). Default is 255.")

    args = parser.parse_args()

    add_alien_glow(args.input_path, args.output_path, args.glow_radius, args.glow_intensity)

python alien-glow.py input.png output.png -r 5 -i 150