BW filter

from PIL import Image

image = Image.open('image.png')

rgb_im = image.convert('RGB')

width, height = image.size

output_image = Image.new('RGB', (width, height))

for row in range(height):
    for col in range(width):
        r, g, b = rgb_im.getpixel((col, row))
        if (r < 128):
            p = 0
        else:
            p = 255
        output_image.putpixel((col, row), (p,p,p))


output_image.save("bw.png")