def draw_circle(event,x,y,flags,param): global ix,iy,drawing,mode,start_x,start_y if event == cv2.EVENT_LBUTTONDOWN: if drawing == False: start_x, start_y = x,y ix,iy = x,y drawing = True elif drawing == True: cv2.line(img,(ix,iy),(x,y),(0,255,0),3) ix, iy = x, y print(drawing) elif event == cv2.EVENT_MBUTTONDOWN: drawing = False cv2.line(img, (ix, iy), (start_x, start_y), (0, 255, 0), 3) print(drawing) # # elif event == cv2.EVENT_RBUTTONUP: # cv2.line(img,(ix,iy),(x,y),(0,255,0),3)# Next we have to bind this mouse callback function to OpenCV # # window. In the main loop, we should set a keyboard binding for# key ‘m' to toggle between rectangle and circle.img = np.zeros((512,512,3), np.uint8)cv2.namedWindow('image')cv2.setMouseCallback('image',draw_circle)while(1): cv2.imshow('image',img) k = cv2.waitKey(1) & 0xFF if k == ord('m'): # 切换模式 mode = not mode elif k == 27: breakcv2.destroyAllWindows() 
