PythonOpenCV第五课：响应鼠标事件画图

先看代码&＃xff1a;

import cv2
import numpy as npwindowname &＃61; &＃39;drawing&＃39;
img &＃61; np.zeros((512,512,3), np.uint8)cv2.namedWindow(windowname)def drawCircle(event, x,y,flags, params):if event &＃61;&＃61; cv2.EVENT_LBUTTONDOWN:cv2.circle(img, (x,y), 60,(0,0,255), -1)cv2.setMouseCallback(windowname, drawCircle)while(True):cv2.imshow(windowname, img)if cv2.waitKey(20) &＃61;&＃61; 27:breakcv2.destroyAllWindows()def main():while(True):cv2.imshow(windowname,img )if cv2.waitKey(0) &＃61;&＃61; 27:breakcv2.destroyAllWindows()if __name__ &＃61;&＃61; "__main__":main()

EVENT_LBUTTONDOWN是鼠标左键按下事件&＃xff0c;cv2.circle画一个圆&＃xff0c;记得按Esc退出程序。

运行看效果&＃xff1a;