utils.py 文件源码

def mask_for_polygons(
        im_size: Tuple[int, int], polygons: MultiPolygon) -> np.ndarray:
    """ Return numpy mask for given polygons.
    polygons should already be converted to image coordinates.
    """
    img_mask = np.zeros(im_size, np.uint8)
    if not polygons:
        return img_mask
    int_coords = lambda x: np.array(x).round().astype(np.int32)
    exteriors = [int_coords(poly.exterior.coords) for poly in polygons]
    interiors = [int_coords(pi.coords) for poly in polygons
                 for pi in poly.interiors]
    cv2.fillPoly(img_mask, exteriors, 1)
    cv2.fillPoly(img_mask, interiors, 0)
    return img_mask