import cv2 import numpy as np blank_image = np.zeros([512, 512, 3], dtype=np.uint8) def draw_circle(event, x, y, flags, param): if event == cv2.EVENT_LBUTTONDOWN: cv2.circle(blank_image, center=(x, y), radius=20, color=(0, 0, 255), thickness=-1) elif event == cv2.EVENT_RBUTTONDOWN: cv2.circle(blank_image, center=(x, y), radius=20, color=(0, 255, 0), thickness=-1) cv2.namedWindow("image") cv2.setMouseCallback("image", draw_circle) while True: cv2.imshow("image", blank_image) # wait 5 seconds then wait for ESC key if cv2.waitKey(5) & 0xFF == 27: break cv2.destroyAllWindows()
References
https://github.com/mhdr/OpenCVSamples/tree/master/011