im2braille

from PIL import Image

def im2braille(im,thres=128):
    # converting PIL.Image image to braille pattern string
    w = (im.width+2)//3
    h = (im.height+4)//5
    # convert to braille
    im = im.convert('L')
    res = [[0x2800 for c in range(w)] for r in range(h)]
    ofs = {(0,0):1,(0,1):2,(0,2):4,(1,0):8,(1,1):16,(1,2):32,(0,3):64,(1,3):128}
    for r in range(im.height):
        for c in range(im.width):
            if im.getpixel((c,r)) >= thres:
                res[r//5][c//3] |= ofs.get((c%3,r%5),0)
    return '\n'.join(''.join(chr(i) for i in resr) for resr in res)