halftone.py

#!/usr/bin/python
import argparse, math

parser = argparse.ArgumentParser()
parser.add_argument(dest='width', type=int)
parser.add_argument(dest='height', type=int)
parser.add_argument('-s', dest='spacing', type=int, nargs='?', default=20)
parser.add_argument('-b', dest='blackness', type=float, nargs='?', default=0.75)
args = parser.parse_args()

max_distance = max(args.width, args.height)
half_width = args.width / 2
half_height = args.height / 2
half_max = max_distance / 2
circles = ''

scale_x = float(max_distance) / args.width
scale_y = float(max_distance) / args.height

x = args.spacing / 2
while (x < args.width):
	y = args.spacing / 2
	while (y < args.height):
		distance_x = abs(x * scale_x - half_max)
		distance_y = abs(y * scale_y - half_max)
		radius = math.sqrt(pow(distance_x, 2) + pow(distance_y, 2))
		size = (1 - (radius / half_max)) * args.spacing * args.blackness
		if size > 0:
			circles += '\t\t<circle cx="%s" cy="%s" r="%.2f" />\n' % (x, y, size)

		y += args.spacing
	x += args.spacing

print '<svg width="%d" height="%d">\n\t<g>\n%s\t</g>\n</svg>' % (args.width, args.height, circles)