Opencv waitkey specific key. See current snippet below; import cv2 key = cv2.
Opencv waitkey specific key what are the numbers for a,s,d,w respectively? Or is there something that says what each key is someplace? not sure what I mean? Nov 21, 2024 · The waitKey() function Before diving into the differences between waitKey(0) and waitKey(1), let’s first understand the purpose and behavior of the waitKey() function itself. startWindowThread () cv2. waitKey() which will wait indefinitely until there is a key press then it will resume the video. waitKey (0) means forever. 13 installed with Homebrew and OpenCV 3. Jan 27, 2020 · OpenCV has a very basic properties for the interface. when opening a video file). Aug 21, 2016 · I'd like to give waitkey commands for any given letter. waitKey (1) & 0xff == ord ('q') was one of the pieces that I toyed with multiple times. this simply looks like broken programming logic, to me ;) why do you need a cin AND a waitKey () there ? (they also work on different windows) Aug 28, 2024 · In OpenCV, the function used to check for key input is waitKey (). By default, it waits for a key press indefinitely (i. Another part of program is to give inputs using curses (curses do NOT wait/stop the other parts of program until user give an input ) So, when I open a camera AND then give an input the program sticks a little bit and this is very very bad. May 28, 2016 · I am working with OpenCV and I want OpenCV to not wait for any key being pressed (default behaviour of cv2. Nov 8, 2022 · if cv2. It only does the specified function when a key is presses. Guess that is also implementation specific. In the case of cv2. waitKey(500) after_display=currentTime() I also know that when you send a screen refresh instruction, yo have to wait for the next frame of the screen refresh rate to appear. time() img = np. detect that by checking waitKey 's result. Experiment with different delay values, explore alternative event handling methods, and always consider the unique requirements of your project. We would like to show you a description here but the site won’t allow us. com has expired and may be renewed by the owner. Dec 16, 2019 · You can implement a pause/resume feature by determining what key was pressed from the return value of cv2. The arrow keys work fine UNTIL I press the TAB key, then they stop working. The key code which is returned is implementation-specific and depends on the used backend: QT/GTK/Win32/etc. When running with pics or videos, you may want to open more than one show home windows, and this characteristic allows you to shut a specific window by way of specifying its name. The keycodes returned by waitKey change depending on which modifiers are enabled. imshow method for a specified period of time. Sep 28, 2021 · OpenCV 4. Jun 22, 2020 · Hello. A modified version of the script Tomasz posted is given Jun 14, 2025 · waitkey () function of Python OpenCV allows users to display a window for given milliseconds or until any key is pressed. waitKey (1) in your code. waitKey(3000) after using cv2. Learn how to efficiently manage key inputs with OpenCV's `cv2. I would like to show two superposed images using the command cv2. For example, if I use cv2. 7. Is there any better way than passing all the keys at ord ()? # Press 'q' to quit key = cv2. Second, it allows you to close an image window when a specific key is pressed. If you use the delay = 0, then your program waits for a key event infinitely, blocking the execution. waitKey (0) will wait forever for a key press. 2 (December 2016) with these two commits. OpenCV’s highgui doesn’t pass window closing events along, so it is a bad idea to close imshow windows using the [X] button or Alt+F4. waitKey (1) & 0xFF # if the `q` key was pressed, break from the loop if key == ord Apr 5, 2021 · I want to know that what actually cv2. If you have multiple windows open at the same time and you want to close then you would use this function. Note that it does not listen on stdin for console input. waitKey(0) until the 0 key is pressed properly whilst the window is in focus. It is similar to destroyWindow () function but this function only destroys a specific window unlike Sep 27, 2016 · It has a main thread that starts a second thread which capture frame from a . To remove the window, use cv::destroyWindow. created from cv::imshow()). This simple example shows how to handle different image formats and modes using OpenCV, providing flexibility for various image processing tasks. The smallest of these flags is Shift at 0x10000. it’s best to use the lowest wait time possible here, which is 1 (or use pollKey() ). Jun 10, 2025 · Remember that the key to success with waitKey() lies in finding the right balance for your specific application. Reading a video file requires processing each frame individually, and then displaying or storing it as needed. waitKey () but then the image doesn't show. Nov 6, 2024 · Explore various solutions to the common issue of cv2. waitKey () function which waits for a specific time for a key press (See here for more details). Otherwise, it returns -1. import cv2 import time image = cv2. waitKey() is a keyboard binding function. Is there any solution, so the program waits a keypress OR the window to be closed? Mar 26, 2025 · Image cropping is a fundamental operation in image processing that involves selecting a specific region of interest (ROI) from an image and discarding the rest. waitKey(1) cmra = cv2. Apr 22, 2016 · After loading an image, and then show the image, cv2. imread ('img1. I donot want to depend on a GUI Window. Or close by press “x” button. I wrote the following code: import random import cv2 img1 = cv2. I'm using this bit of code to wait for a specific key: if I know that it is required if you want to show changes in an image during a loop, or even the loop itself. Dec 30, 2023 · Understanding the Purpose of 0xFF in cv2. The code is Apr 12, 2023 · Explore the cv2. . Jan 29, 2022 · In this tutorial we will learn what is OpenCV cv2. zeros((400,400),dtype=np. From the docs: cv2. waitKey (0) cv2. whenever i press the "r" key the point on opencv image window is moving right direction, for "L" towards left ,for "u" upward direction as bellow. avi') This is my reference tutorial. The lowest byte is consistently the same, so 0xFF (0b11111111) is applied as a bitmask to extract only the values from the lowest byte, which is then compared to the ordinals that you get from the ord function. The waitKey () function waits for key input for a specified number of milliseconds, and if a key is pressed, it returns the ASCII Jan 6, 2023 · key = cv2. This is especially useful for coping with assets successfully during image processing tasks. waitKey ( [delay]) → retval The function waitKey waits for a key event infinitely (when delay <= 0 ) or for delay milliseconds, when it is positive. waitKey () can not work properly when I use opencv in python idle or jupyter console. In Python 3 programming, waitKey() is a function provided by the OpenCV library that waits for a key event to occur and returns the ASCII value of the key pressed by the Sep 25, 2020 · OpenCV to close the window on a specific key? Asked 5 years, 1 month ago Modified 4 years, 4 months ago Viewed 17k times Jan 4, 2023 · I got the impression (but without solid data) that the duration of continued action after releasing increases (proportionnal?) with the duration during which the key was pressed. Because as stated above, if the terminal is in focus nothing happens and code execution stucks at the cv2. By using different keys, you can enable features such as quitting the program, navigating through images, or triggering specific actions based on user input. imshow ('test',cv2. 16 hours ago · Hi, Here my first program (python and windows11 opencv-python 4. What was before int key_pressed = waitKey(0); cout << " Jul 24, 2020 · Then, as no HighGUI windows are active, waitKey () will never return and the program blocks. First: cv2. waitKey([, delay]) waits for a key event infinitely (when delay <= 0) or for delay milliseconds, when it is positive. I tried using pygtk's key-press-event, but this doesnot wait for key press. waitKey can't catch multiple key presses simultaneously. VideoCapture('video. , until a key is pressed), and it returns the ASCII value of the key that was pressed. waitKey(1) this is, in fact, negligible but its use provides the user the opportunity to press a key (the key might be caught in some next iteration but does not make a big difference). 2. In case this is OS specific I am using Windows To illustrate what I mean here’s a small example: import cv2 import time import numpy as np empty = np. ). Mar 4, 2025 · The program will wait indefinitely for a key press (via waitKey (0)) before closing all image windows with destroyAllWindows (). This function is commonly used to wait for a key event to occur, allowing the program to pause and respond accordingly. Feb 17, 2025 · I took back a python project that uses openCV to show images in a separate window. waitKey(50) will suspend the program 50 milliseconds, during that time the GUI event loop will run (making it so you can resize/move windows), if a keyboard event happens during that 50ms while the window in question has focus, it will be stored in the variable k The value stored is an integer, ord('a') is 97 which is what waitKey would return if you pressed A. waitKey (25) will display a frame for 25 ms, after which display will be automatically closed. waitKey(0) print(k) time Jul 7, 2020 · Hi, I want to close the video frame with any key from the keyboard. With OpenCV’s robust tools for video capture, the world of motion becomes accessible, enabling us to extract insights, analyze movement, and unlock the cinematic potential of visual data. This is because waitKey is simply waiting for a delay, and during this delay Highgui runs whatever tasks need to be done May 23, 2013 · I have involved with opencv key function ie cvWaitKey (0). Second one is to call cvStartWindowThread() at the start of your program to allow OpenCV updating its windows automatically. 3; Visual Studio 2017 MFC; C++; Windows 10 Difficult to explain and too much code involved to put here but I will try to explain. ，测试 依次按上 下 左 右方向键，输出： nbsp 测试代码： 依次按上 下 左 右方向键，输出： nbsp 官方说，waitKeyEx和waitKey类似，Key code is implementation specific and d In learning OpenCV display images, there is often such a code in the end Without this code, the picture flashes Add CV2. waitKey ( [delay]) The function waitKey waits for a key event infinitely and the delay is in milliseconds. If a key was pressed during that time, it returns the key's ASCII code. If given 0 it waits for infinite till any key is pressed to destroy Mar 7, 2011 · cvWaitKey(x) / cv::waitKey(x) does two things: It waits for x milliseconds for a key press on a OpenCV window (i. 5, C++, Visual Studio 2017, Windows 10 When using waitKey () to process an imShow, is there an optimum time to use for the waitKey () or is waitKey (1) more than sufficient? shiganai-coder. Here is how the class can be used: Mar 26, 2014 · OpenCV does not have a priority on high-efficiency GUI implementation. imread(". Subsequent presses of the TAB key cause a 9 to be printed. OpenCV, a powerful open-source computer vision library, provides efficient methods for cropping images in both Apr 21, 2017 · Dear all, I have a MacBook Air Sierra 10. Two quetsions rise Dec 10, 2019 · OpenCV: Detect whether a window is closed. ---This k = cv2. destroyAllWindows This will display the image and close the image after a key is pressed (as expected) but I want to be able to close the image without user input after a set time. See current snippet below; import cv2 key = cv2. My c The first part can be done using the OpenCV cv2. OpenCV Computer Vision with Python A good source for installation in various OS, code examples, etc. DestroyWindow () function in OpenCV is used to shut a specific window created the use of OpenCV. WAITKEY (delay), enter specific values in parentheses delay = 0: Live and long What is wait key in OpenCV? The function waitKey () waits for a key event for a “delay” (here, 30 milliseconds). imshow('test', img), the image window should close automatically after 3 seconds, but it won't! Apr 15, 2025 · OpenCVの waitKey は、指定したミリ秒間キー入力を待つ関数で、画像表示や動画再生中に処理を一時停止させる際に使用されます。 引数に0を指定すると無期限に入力待ちとなり、正の整数を指定するとそのミリ秒間だけ待機します。 戻り値は押されたキーのASCIIコードで、特定のキー入力を検出 Oct 1, 2025 · 文章浏览阅读6. I have tried with waitKey (0), but it just displays an image. VideoCapture(0) while True: try: camera_avail, frame = cmra. I have made sure that the include directories are correct, and that the linker is also correct. destroyWindow('Train Device') break I just want to close only a specific window when i am clicking on the letter (e) but when i use this one it close everything all the frames and not only the specific one. Is there a workaround with cpp interface to accomplish this without use of waitKey () ? Apr 26, 2016 · I'm debugging some C++ code that use OpenCV on Ubuntu 14, which is known to work On Ubuntu 12 and maybe with other OpenCV library build. imshow('empty', empty) k = cv2. Contact Us Privacy Policy Terms of Use Do not sell my data Advertiser Wanted Jul 9, 2015 · waitkey () does not return the value of the character pressed 5 days ago · Class for video capturing from video files, image sequences or cameras. Jan 18, 2019 · 本文总结了OpenCV中waitKey无法正常捕捉方向键问题的原因，并提供了解决方案，包括使用waitKeyEx函数。 Apr 5, 2021 · I want to know that what actually cv2. imread (file) cv2. For the second part, we first need to create a bouncing ball screensaver. Feb 5, 2014 · I am truing to show the camfeed into a window using imshow () but it needs waitKey () after each frame. waitKey (delay) Parameters: delay: The time in milliseconds after which windows needs to destroyed. If you don't like calling waitkey (1), you may need to use another toolbox for image display. My current code is as follows: import cv2 while True: key = cv2. 1 day ago · This quick-start shows the recommended way for most users to get OpenCV in Python: install from PyPI with pip. If I don't include "waitKey" - the image will instantly disappear as soon as it's displayed. it actually holds the message loop, nessecary to render any gui things. addWeighted and random. I have a pygtk window open How do i wait for a particular key press in python or pygtk?? Mar 24, 2025 · I am using cv2. The Essence of Video Capture: Jan 13, 2012 · OpenCV allows to do this event exchange in system-independent way. In one mode, without the use of a camera, the main thread loops through a video file and “shows” the frames in the named window videoWindow. The project consist of a local web server with Flask that can do various operations depending on the API call. Since the OS has a minimum time between switching threads, the function will not wait exactly delay ms, it will wait at least delay ms, depending on what else is running on your computer at that time. waitKey() is doing … I know that it is used for waiting for a particular amount of milliseconds or for indefinite period of time (if 0 is mentioned) . waitKey function in OpenCV, its syntax, and various use cases, how to control image/video display and handle keyboard events. resize (img1 Oct 21, 2017 · I have a similar issue with opencv 4. the timeout is merely a convenience that keeps the GUI event loop running for that long (or until a key is pressed), in case you don’t need to do anything else during that time. 3 days ago · For example, waitKey (0) will display the window infinitely until any keypress (it is suitable for image display). jpg") cv2. Aug 28, 2019 · I just finished some OpenCV code and cv2. Unlike static images, videos consist of multiple frames played in sequence, requiring careful handling of frame rates and smooth processing. It takes time in milliseconds as a parameter and waits for the given time to destroy the window, if 0 is passed in the argument it waits till any key is pressed. waitKey(0) & 0xFF == ord("e") : cv2. waitkey method allows you to display a window that has been shown with the cv2. 'Train Device' is name Jan 8, 2013 · Because we want our window to be displayed until the user presses a key (otherwise the program would end far too quickly), we use the cv::waitKey function whose only parameter is just how long should it wait for a user input (measured in milliseconds). Mar 13, 2022 · OpenCV 4. Dec 5, 2018 · According to the OpenCV Documentation: The function waitKey waits for a key event infinitely (when delay <= 0 ) or for delay milliseconds, when it is positive. # Key codes depend on the backend hence the "or" for arrow keys & F1. When you call imshow it doesn't immediately draw itself (in my experience and afaik), it requires a call to waitKey before it attempts to process it's event loops. 4. I want to stream the video from webcam and want to close the streaming when I press any key. waitKey(20) & 0xFF ==27: Can anybody tell me the working of this this code in python Dec 8, 2013 · I used opencv's cv. jpg') img2 = cv2. 5. A simple way to catch two key combination, you can record the last catched key and compare it with current catch key, check if these two keys meet your desired key combination. uint8) while True: cv2. If the FPS is equal to 20, then you should wait 0,05 seconds between displaying the consecutive frames. I want to start to capture image or record only when user customised key combination is used. There are two documented methods to do this. I have created a test project to set everything up in Visual Studio 2019. The project is in python 3. This adds complexity, demanding efficient computation and dynamic frame management. 12. 86. waitKeyEx(1) #waitKeyEx returns the ASCII value of the key if there is one, otherwise the key code; 27=Esc. When that project is working, I exported that as a template, and used that to create my actual project. waitKey (25) will display a frame and wait approximately 25 ms for a key press (suitable for displaying a video frame-by-frame). I have a program and a part of it is to open a camera with opencv. So just put waitKey(50) after imshow() in order to have the desired speed for the playback. Maybe because waitKey() returns ASCII-codes, but arrow keys don't have them (as explained here). ) It handles any windowing events, such as Oct 28, 2022 · How to use waitkey with VideoCapture () Python Maia1003 October 28, 2022, 4:14am 1 May 23, 2019 · I want to implement a function that while cv2 shows some video, it can wait for two different key inputs and respond to them differently. 86): import time import numpy as np import cv2 as cv tps_start = time. waitKey(1) & 0xFF to capture key events, but I found that it cannot correctly detect the Delete key. did you want this ? (waitKey (10) might be the other idea. Can anyone suggest how to get this done ? I have read the cv2. imshow displaying a blank window or not functioning correctly in OpenCV with Python. In your The cv2. Jan 3, 2023 · Python Opencv destroyAllWindows () function allows users to destroy or close all windows at any time after exiting the script. 4, Python 2. (If x <= 0, it waits indefinitely for the key press. NumLock, CapsLock, and the Shift, Ctrl, and Alt keys all modify the keycode returned by waitKey by enabling certain bits above the two Least Significant Bytes. 1 day ago · A common question arises: *Why does `waitKey (0)` display still images, while `waitKey (1)` shows smooth live video?* In this blog, we’ll demystify `waitKey ()`, explore the key differences between `waitKey (0)` and `waitKey (1)`, and explain why their parameter values drastically impact whether you see a frozen frame or a flowing video. I also updating openCV from version 4. waitKey()), but to wait for specific keys that I define (and do subsequent actions). Mar 24, 2025 · In this article, we will explore the fundamental operations of pixel-level image manipulation in detail and demonstrate how they Jan 18, 2019 · nbsp 在win python opencv . However, I found that the template code is no longer working properly. 11. Some OpenCV users use QT for that, others use lower-level API. This technique is widely used in various applications, such as object detection, face recognition, and image enhancement. In OpenCV, the waitKey () function is used to wait for a specified amount of time for a key event to occur when displaying images or videos. Jan 8, 2013 · For example, waitKey (0) will display the window infinitely until any keypress (it is suitable for image display). The current behavior on all platforms is this: waitKey returns -1 or the lowest 8 bits of the keycode That is done with & 0xFF in the library source. waitKey ()`, including multiple key handling and setting a timeout for user interaction. But , when I ran the following python code first a grey window popped up(for ten seconds ) and then after 10s , the image came up. Referred to a few aritcles on web that say highgui requires waitkey () to be called in order to get time to update the window. Supose I save a time variable just before and after displaying an image: before_display=currentTime() k = cv2. 8 and I am upgrading it to python 3. May 29, 2021 · My experience is that waitkey(1) waits AT LEAST a millisecond, when I use it to display an image in my code I see a delay of about 5 ms. zeros((256 Aug 17, 2024 · When the user wants to close the window through the press of the 0 key, he/she has to make sure that the 0 key is pressed whilst the window is in focus. First one is cvWaitKey() (just call cvWaitKey(1) after you close the last image). Aug 7, 2014 · From the OpenCV documentation: The function cv. Mar 4, 2025 · Understanding waitKey The waitKey function is a built-in OpenCV function that serves two primary purposes. It may sound it should be an easy task, but surprisingly, this is a quite common problem for OpenCV’s user … Feb 26, 2025 · OpenCV is widely used for image and video processing. waitkey library but could not get a clear idea of this. Since the OS has a minimum time between switching threads, the function will not wait exactly delay ms, it will wait at least delay ms Aug 9, 2017 · Although there are many online sources saying waitKey() works with arrows, it didn't return proper key codes on my Windows system either (always returned 0). waitkey() function and how it can be used to display images and videos along with examples Nov 17, 2019 · So recently, I started using OpenCV. It also explains virtual environments, platform notes, and common troubleshooting. Currently looking for a way around using waitkey to display an image and avoid that delay. One API call result in the following set of lines of code: window Feb 13, 2016 · The behavior of waitKey has fundamentally changed in v3. I tried removing the cv2. To pause the video, you can pass no parameter (or 0) to cv2. How do I pause a video in OpenCV Python? Feb 23, 2024 · I have a short script to start camera on laptop. 7w次，点赞36次，收藏138次。本文深入解读了OpenCV中的waitKey函数，并通过实例演示了不同使用方式的效果，包括无限等待、指定时间等待及如何通过按键结束循环。 Sep 1, 2021 · Hi, I know that for displaying an image with opencv, I have to call the WaitKey function. Its argument is the time in milliseconds. Sep 14, 2015 · Python: cv2. Apr 4, 2016 · If you want to use HighGUI from OpenCV, you could write your own UpdateGUI hacking the waitKey code around delay<=0 and choose to serve only message for a specific window (window->hwnd == message. Feb 4, 2025 · The cv2. 0. Is there any way to have cv2 display an image until a variable is updated? Right now my code looks like: while True: OpenCV, a versatile computer vision library, extends its capabilities beyond images to delve into the dynamic realm of video. Second: The ord () method returns an integer representing a Unicode code point for the given Unicode character. oni recording file (asus xtion pro live) does some processing and through the Qt signal-slot mechanism pass the frame to the main thread, which display it using imshow (). it only has to be entered periodically to keep the GUI window somewhat responsive. waitKeyEx returns -1 or the full keycode The result from this can carry additional flags for special keys, such as arrow keys, F-keys, modifiers Jun 26, 2016 · I have this kind of code at the end of my whole code . Another clue is that the 1st time I press the TAB key, it DOES NOT print out a 9, so it is somehow processing the tab character differently. It doesn't take any parameters and doesn't return anything. Oct 16, 2019 · 4 I think cv2. 46 to version 4. I think the continued action some times exceeded 1 minute (ie several hundreds, maybe even more than 1000 key presses detected once the key was already released) Sep 3, 2022 · When using waitKey (0) in a loop with some delays, more key presses are ‘picked up’ before waitKey is ever called for a second time. Syntax: cv2. g. You can use the following code to display a frame until a key is pressed: In OpenCV, the waitKey () function is used to wait for a specified amount of time for a key event to occur when displaying images or videos. The function waits Nov 22, 2016 · I'm writing a method and currently I have cv2. waitkey () but this functions only if a GUI window is active. It waits for a specified amount of time for a key event to occur and returns the key code of the pressed key. In another mode, using a camera, the main thread calls a dialog box Nov 11, 2015 · Is there a way to get a specific frame using VideoCapture() method? My current code is: import numpy as np import cv2 cap = cv2. It returns the code of the pressed Apr 5, 2021 · the number doesn’t matter to the “drawing”. Jan 11, 2015 · It would seem that everything else but the waitkey is taking around 2ms, which will give me 6ms or so for other openCV processing - all in keeping up with 120fps - this is my goal. May 5, 2023 · The waitKey() function in OpenCV is used to introduce a delay in the program and also to capture and process keyboard events. e. Note : OpenCV team maintains PyPI packages May 25, 2021 · exit your program using a key, such as ESC, or any key really. To get the number The Modifier keys (ctrl/shift/num lock/etc) can change the upper bits, which can make the key press not register (see here). Jan 19, 2024 · Exploring alternative keys for the waitKey () function in OpenCV with Python 3 can provide additional functionality and interactivity to your programs. As the documentation mentioned, It doesnt talk about released events: The function waitKey waits for a key event infinitely (when 𝚍𝚎𝚕𝚊𝚢≤0 ) or for delay milliseconds, when it is positive. jpg') cv2. /my. imshow(“Image Apr 7, 2023 · Introduction to OpenCV waitKey The binding function on the keyboard, which waits for a specified number of milliseconds for any keyboard event to happen, is called waitKey () function in OpenCV, and if the value 0 or any negative value is provided as a parameter to the waitKey () function, it is a special value that causes the currently running thread to wait infinitely for the key event to Jan 3, 2023 · Python OpenCv waitKeyEx () method is similar to waitKey () method but it also returns the full key code. waitKey () is doing … I know that it is used for waiting for a particular amount of milliseconds or for indefinite period of time (if 0 is mentioned) . First of all this is a mult-thread app. This is the command to close the window when i click on letter 'e' if cv2. waitKey( Jan 20, 2015 · We would like to show you a description here but the site won’t allow us. As @Miki said, you can use delay = 1, so that waitKey won't block. 1 day ago · OPENCV_LEGACY_WAITKEY Some modules have multiple available backends, following variables allow choosing specific backend or changing default priorities in which backends will be probed (e. waitKey (1) When working with computer vision applications using OpenCV, you may come across the function cv2. What I want to do is to implement a pause key, so pressing for example 'p' the processing pause. As explained in the OpenCV documentation, HighGui ( imshow () is a function of HighGui) need a call of waitKey regularly, in order to process its event loop. OpenCV Mar 10, 2022 · what you do with waitKey there is a bad idea because of that . you don’t have to spend all idle time in waitKey . Imagined there would be a table with (letter == N ) on the waitkey API, but I did not see it. imread ('img2. If you need OS‑specific alternatives (system packages or source builds), see the OS pages linked below, but those are not required for typical Python use. The class provides C++ API for capturing video from cameras or for reading video files and image sequences. Jan 19, 2019 · as a rule of thumb: you only need 1 waitKey (0) call, ever. First, it waits for a specified amount of time for a key event. 0 in python3. uniform () in a while loop. 2 days ago · For example, waitKey (0) will display the window infinitely until any keypress (it is suitable for image display). every waitKey call “draws” everything that needs to be “drawn”. waitKey(). Nov 5, 2017 · waitKey () might be a misnomer. read Jan 30, 2019 · The problem is that cv2 requires me to put in "waitKey" - which will either wait for a number of milliseconds or until a key is pressed. hwnd). xyhj lhln jxdrs qywy uotl iuuzrta ghdid gcsds bxxl dptke nbhshs zjvjbt fhwf ajab gxdi