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wyojustin/dither.py

Created October 11, 2020 16:37
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  1. wyojustin created this gist Oct 11, 2020.
    48 changes: 48 additions & 0 deletions dither.py
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,48 @@
    from PIL import ImageOps
    from PIL import Image
    import numpy as np
    import pylab as pl
    import sys

    usage = '''USAGE:
    python dither.py <input_image_fn> [dim]
    '''
    if len(sys.argv) < 2:
    print(usage)
    sys.exit()

    img_fn = sys.argv[1]

    DIM = 5
    if len(sys.argv) > 2:
    DIM = float(sys.argv[2])

    img = Image.open(img_fn)
    size = img.size
    ##max(size) / reduce = 1000
    reduce = min(size) / 1000


    print(size[0]//reduce, size[1] // reduce)
    img.thumbnail((size[0]//reduce, size[1]//reduce))
    img.convert('1').save('out_1.bmp')
    rgb = img.split()
    if len(rgb) == 3:
    r,g,b = img.split()
    else:
    r,g,b,a = img.split()

    zero = r.point(lambda i: 0)
    if True:
    r = r.point(lambda i:i/DIM)
    g = g.point(lambda i:i/DIM)
    b = b.point(lambda i:i/DIM)

    white = Image.merge('RGB', (r, g, b))
    neg = ImageOps.invert(white)

    one_neg = neg.convert('1')
    out_fn = '%s_1_neg.bmp' % img_fn[:-4]
    one_neg.save(out_fn)
    print('wrote', out_fn)