passpotrace.py 文件源码

def passpotrace(image, optionargs=[]): 
    # potrace supports only pnm (pbm, pgm, ppm), bmp
    # and cv2.imencode() supports all of them.

    # convert to bmp binary so that potrace can handle it
    retval, buf = cv2.imencode('.bmp', image)
    if retval == False:
        raise ValueError('The Given image could not be converted to BMP binary data')
    # convert buf from numpy.ndarray to bytes
    binbmp = buf.tostring()
    #optionargs = []

    args = [
        POTRACE,
        '-', '-o-', '--svg'
    ] + optionargs

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

    return binsvg