You need to perform the following steps:
- Import the modules we're going to use:
import cv2import numpy as np
- Define the function to display the optical flow:
def display_flow(img, flow, stride=40): for index in np.ndindex(flow[::stride, ::stride].shape[:2]): pt1 = tuple(i*stride for i in index) delta = flow[pt1].astype(np.int32)[::-1] pt2 = tuple(pt1 + 10*delta) if 2 <= cv2.norm(delta) <= 10: cv2.arrowedLine(img, pt1[::-1], pt2[::-1], (0,0,255), 5, cv2.LINE_AA, 0, 0.4) norm_opt_flow = np.linalg.norm(flow, axis=2) norm_opt_flow = cv2.normalize(norm_opt_flow, None, 0, 1, cv2.NORM_MINMAX) cv2.imshow('optical flow', img) cv2.imshow('optical flow magnitude', norm_opt_flow) k = cv2.waitKey(1) if k == 27: return 1 else:
