Convert an image to drawing instructions

image_to_cs.py

"""
Convert an image to drawing instructions.

Dependencies:
* PIL, the Python Imaging Library


This basically write color values for each pixel, with minor cleverness to
reduce output size:

  im = Image.open("file.jpg")
  width, height = im.size
  
  pix = im.load()
  for x in xrange(width):
      for y in xrange(height):
          print "stroke(%s, %s, %s);" % pix[x, y]
          print "point(%s, %s);" % (x, y)
"""

import sys

from PIL import Image


def method_a(im):
    pix = im.load()
    for x in xrange(width):
        for y in xrange(height):
            print "stroke(%s, %s, %s);" % pix[x, y]
            print "point(%s, %s);" % (x, y)


def method_b(im):
    pix = im.load()
    colors = {}
    for x in xrange(width):
        for y in xrange(height):
            color = pix[x, y]
            if not color in colors:
                colors[color] = []
            colors[color].append((x,y))
    for color, points in colors.iteritems():
        print "stroke(%s, %s, %s);" % color
        for point in points:
            print "point(%s, %s);" % point


def method_c(im):
    print """
var p = function() {
    stroke(arguments[0], arguments[1], arguments[2]);
    for (var i = arguments.length - 1; i >= 4; i -= 2) {
        point(arguments[i - 1], arguments[i]);
    }
};

var d = function(arr) {
    for (var i = arr.length; i >= 0; i--) {
        p.apply(null, arr[i]);
    }
};
"""
    pix = im.load()
    colors = {}
    for x in xrange(width):
        for y in xrange(height):
            color = pix[x, y]
            if not color in colors:
                colors[color] = []
            colors[color].extend((x,y))
    first = True
    print "d(["
    for color, coords in colors.iteritems():
        if not first:
            sys.stdout.write(",\n")
        sys.stdout.write("[%s,%s,%s" % color)
        sys.stdout.write(",%s]" % ",".join(str(coord) for coord in coords))
        first = False
    print "]);"


if __name__ == "__main__":
    if len(sys.argv) < 1:
        print >>sys.stderr, "USAGE: image_to_cs.py FILENAME"
        sys.exit(-1)
    
    filename = sys.argv[1]

    im = Image.open(filename)
    #im = im.resize((400, 400), Image.ANTIALIAS)
    width, height = im.size
    print >>sys.stderr, "width:%s height:%s" % (width, height)

    method_c(im)

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