HYTOS

#!/usr/bin/env/python3

# coding: utf-8

import numpy as np, cv2, subprocess

import os

# potrace command

POTRACE = os.path.dirname(os.path.realpath(__file__)) + '\\potrace.exe'

def passpotrace(image): 

    # convert to bmp binary so that potrace can handle it

    retval, buf = cv2.imencode('.bmp', image)

    if retval == False:

        raise ValueError('Failed to convert into BMP binary data')

    # convert buf from numpy.ndarray to bytes

    binbmp = buf.tobytes()

    args = [

        POTRACE,

        '-', '-o-', '--svg'

    ]

    p = subprocess.Popen(

        args,

        stdin=subprocess.PIPE,

        stdout=subprocess.PIPE,

        stderr=subprocess.PIPE,

        shell=False

        )

    stdout, stderr = p.communicate(input=binbmp)

    if len(stderr) != 0:

        raise RuntimeError('Potrace threw error:\n' + stderr.decode('utf-8'))

    return stdout

if __name__ == '__main__':

    execpath = os.path.dirname(os.path.realpath(__file__))

    testpic = cv2.imread(execpath + '\\res\\UY1-K-2007_P1_300dpi_black.png', cv2.IMREAD_GRAYSCALE)

    svg = passpotrace(testpic).decode('utf-8')

    file = open(execpath + '\\res\\UY1-K-2007_P1_300dpi_black.svg', 'w')

    file.write(svg)

    file.close()