import numpy as np
import cv2

def draw_grid(img: np.ndarray, grid_w: int, grid_h:int):
    """划格网"""
    img_h, img_w, _ = img.shape
    # 绘制横向网格线
    for i in range((img_h // grid_h)+1):
        cv2.line(img, (0, i*grid_h), (img_w, i*grid_h), (0, 255, 0), 2)
    # 绘制纵向网格线
    for i in range((img_w // grid_w)+1):
        cv2.line(img, (i*grid_w, 0), (i*grid_w, img_h), (0, 255, 0), 2)
    return img