Opencv mouse and keyboard events

1、 Window cycle read

import numpy as np
import cv2
import matplotlib.pyplot as plt

import os
from itertools import cycle

filename = os.listdir("../images")
img_iter = cycle([cv2.imread(os.sep.join(["../images",x]))for x in filename])
key = 0
while key != 27:
    cv2.imshow("img",next(img_iter))
    key = cv2.waitKey(42)

2、 Get keyboard value

import numpy as np
import cv2
import matplotlib.pyplot as plt

import os
from itertools import cycle

img = cv2.imread("../images/img.jpg")
key = 0
while key != 27:

    cv2.imshow("img",img)
    key = cv2.waitKey()
    msg = "{} if pressed!".format(chr(key) if key < 256 else key)
    print(msg)

3、 mouse

import numpy as np
import cv2
import matplotlib.pyplot as plt

import os
from itertools import cycle


def on_mouse(event,x,y,flags,param):

    if event == cv2.EVENT_LBUTTONDOWN:
        print(" Press the left mouse button , Location ({},{})".format(x,y))
    elif event == cv2.EVENT_LBUTTONUP:
        print(" Left mouse button raised , Location ({},{})".format(x,y))
    elif event == cv2.EVENT_LBUTTONDBLCLK:
        print(" Double click with the left mouse button , Location ({},{})".format(x,y))


    elif event == cv2.EVENT_RBUTTONDOWN:
        print(" Press the right mouse button , Location ({},{})".format(x,y))
    elif event == cv2.EVENT_RBUTTONUP:
        print(" Right click to lift up , Location ({},{})".format(x, y))
    elif event == cv2.EVENT_RBUTTONDBLCLK:
        print(" Double click with the right mouse button , Location ({},{})".format(x, y))


    elif event == cv2.EVENT_MBUTTONDOWN:
        print(" Press the mouse wheel , Location ({},{})".format(x, y))
    elif event == cv2.EVENT_MBUTTONUP:
        print(" Lift the mouse wheel , Location ({},{})".format(x, y))
    elif event == cv2.EVENT_MBUTTONDBLCLK:
        print(" Double click the mouse wheel , Location ({},{})".format(x, y))

    elif event == cv2.EVENT_MOUSEMOVE:
        print(" Mouse movement , Location ({},{})".format(x, y))


cv2.namedWindow("mouse event")
cv2.setMouseCallback("mouse event",on_mouse)
cv2.waitKey(0)