Converts black and white image to svg as vector pixels. Useful for converting bmp fonts. eg: `blackandwhite_to_vectorpixels.py ./bmp_glyphs/ ./svg_glyphs/ bmp`

blackandwhite_to_vectorpixels.py

from PIL import Image
import svgwrite
import os
import argparse


def bmp_to_svg(filename, multiply =1):

	img = Image.open(filename)
	w, h = img.size
	pixel_acc = img.load()

	generated_paths = paths_gen(pixel_acc, w,h, multiply=multiply)

	dwg = svgwrite.Drawing(profile='tiny')
	for path in generated_paths:
		options = path
		kwoptions = {} #{"fill":"black"}
		dwg.add(dwg.polygon(options, **kwoptions))

	#clip_path = dwg.defs.add(dwg.clipPath())
	#clip_path.add(dwg.Rect(insert=(0,0), size=((w*multiply)+1, (h*multiply)+1)))
	return dwg

def paths_gen(pixel_acc, w, h, multiply = 1):
	m = multiply
	paths = []
	for y in range(0,h):
		for x in range(0,w):
			pix = pixel_acc[x,y]
			brightval = sum(pix) /3
			if brightval < 128:
				paths.append([
						##top left
						(x * m, y * m),
						##top right
						((x+1) * m, y * m),
						##bottom right
						((x+1) * m, (y+1) * m),
						##bottom list
						((x) * m, (y+1) * m),
						##close back to top left
						#(x, y), 
					])
	return paths


def main():
	parser = argparse.ArgumentParser(
		description='Script to convert black and white images into vector art')
	parser.add_argument("input_dir")
	parser.add_argument("ouput_dir")
	parser.add_argument("in_ext", default="bmp", help="file extension of images in input folder")
	parser.add_argument("-m", "--multiply", default=1, type=int)
	## TODO
	#parser.add_argument("-u", "--union", store=True, help="unifies adjecent polgons")
	#parser.add_argument("-s", "--simplify", store=True, help="removes points that are part of a straight line")
	#parser.add_argument("-c", "--compress", store=True, help="same as '--union --simplify'")
	
	args = parser.parse_args()
	

	cdir = os.path.abspath(args.input_dir)

	fn_gen = ( x for x in os.listdir(cdir)
				 if x.endswith('.'+args.in_ext)
			 )

	for count, filename in enumerate(fn_gen):

		full_filename =  os.path.join(cdir, filename)

		new_fn = "{}_.svg".format(filename)
		new_fullfn =  os.path.join(args.ouput_dir, new_fn)


		svg = bmp_to_svg(full_filename, multiply=args.multiply)
		print "Converted file: '{}'".format(full_filename)
		svg.filename = new_fullfn
		svg.save()

if __name__ == '__main__':
	main()