'given image index, find out full path
Parameters:
index: int
index of a specific image
Returns:
full path of this image'

def image_path_from_index(self, index):

    assert (self.image_set_index is not None), 'Dataset    not    initialized'
    name = self.image_set_index[index]
    image_file = os.path.join(self.image_dir, 'images', name)
    assert os.path.isfile(image_file), 'Path    does    not    exist:    {}'.format(image_file)
    return image_file
