'Check to see if a ImageMagickWriter is actually available.
Done by first checking the windows registry (if applicable) and then
running the commandline tool.'

@classmethod
def isAvailable(cls):

    bin_path = cls.bin_path()
    if (bin_path == u'convert'):
        cls._init_from_registry()
    return super(ImageMagickBase, cls).isAvailable()
