直接用图说话
import cv2
import numpy as np
src = cv2.imread("9.jpg")
src = cv2.resize(src, (0, 0), fx=0.5, fy=0.5)
# 交互式,返回 (x_min, y_min, w, h)
r = cv2.selectROI('input', src, True)
# roi区域
roi = src[int(r[1]):int(r[1] + r[3]), int(r[0]):int(r[0] + r[2])]
# 原图mask,与原图等大小
mask = np.zeros(src.shape[:2], dtype=np.uint8)
# 矩形roi
rect = (int(r[0]), int(r[1]), int(r[2]), int(r[3])) # 包括前景的矩形,格式为(x,y,w,h)
后期会补全代码或者发布资料



