Python+OpenCV image processing (1) - read and display a picture

　　After configuring all the environments, start the first step of image processing using python+opencv.

　　Read and display an image:

import cv2 as cv
src=cv.imread('E:\imageload\example.png')       
cv.namedWindow('input_image', cv.WINDOW_AUTOSIZE)
cv.imshow('input_image', src)
cv.waitKey(0)
cv.destroyAllWindows()

　　Output effect:

　　

　　Code Explanation:

　　src=cv.imread('E:\imageload\example.png')   

　　#Read the picture of this path Note that the path here must be all in English, not Chinese, but the separator \ is optional, and it can also be in the form of / \\ // (at least in python3)

 

　　cv.namedWindow('input_image', cv.WINDOW_AUTOSIZE) 

　　 The #namedWindow function is used to create a window. The default value is WINDOW_AUTOSIZE, so in general, we can fill in the first variable for this function. Actually this

A line of code can be displayed normally without it (imshow will display it below)

　

　　cv.imshow('input_image', src) 

　　#Display an image in the specified window

　　　　　　　　　　　　

　　cv.waitKey(0)           

　　# Parameter=0: (It can also be a value less than 0) always displayed, and it will disappear when a key is pressed on the keyboard     

　　     Parameter > 0: how many milliseconds to display

 

　　cv.destroyAllWindows() 

　　 #Delete all created windows and release resources

 

　　Note: If the namedWindow and imshow functions are used at the same time, the first parameter name of the two functions must be the same

 　　An important point: Project Encoding must be set to utf-8 in pycahrm, otherwise Pycharm will report an error when commenting Chinese characters in the newly created py file

　　

　　

　　Of course, if you have created a new py file, to avoid errors, you should comment on the first line of the code: #encoding=gbk