DestroyWindow does not close window on Mac using Python and OpenCV

This solution works for me (under Ubuntu 12.04 with python open in the shell):

Re-invoke cv.ShowImage after the window is ‘destroyed’.

You need to run cv.startWindowThread() after opening the window.
I had the same issue and now this works for me.

Hope this helps for future readers. And there is also a cv2 binding (I advise to use that instead of cv).

This code works for me:

import cv2 as cv
import time

WINDOW_NAME = "win"

image = cv.imread("ela.jpg", cv.CV_LOAD_IMAGE_COLOR)
cv.namedWindow(WINDOW_NAME, cv.CV_WINDOW_AUTOSIZE)
initialtime = time.time()

cv.startWindowThread()

while (time.time() - initialtime < 5):
  print "in first while"
cv.imshow(WINDOW_NAME, image)
cv.waitKey(1000)

cv.waitKey(1)
cv.destroyAllWindows()
cv.waitKey(1)

initialtime = time.time()
while (time.time() - initialtime < 6):
    print "in second while"

The same issue happens with the C++ version, on Linux:
Trying to close OpenCV window has no effect

Fiddling around with this issue in the python console I observed the following behavior:

• issuing a cv2.imshow after cv2.destroyWindow sometimes closes the window. Albeit the old window pops up again with the next highgui call, e.g., cv2.namedWindow
• the third call of cv2.waitKey after cv2.destroyWindow closed the window every time I tried. Additionally the closed window remained closed, even when using cv2.namedWindow afterwards

Hope this helps somebody.

(I used Ubuntu 12.10 with python 2.7.3 but OpenCV 2.4.2 from the 13.04 repos)

After searching aroung for some time, none of the solutions provided worked for me so since there’s a bug in this function and I did not have time to fix it, I did not have to use the cv2 window to show the frames. Once a few frames have been saved, you can open the file in a different viewer, like VLC or MoviePlayer ( for linux ).

Here’s how i did mine.

 import cv2

 threadDie = True # change this to false elsewhere to stop getting the video
 def getVideo(Message):
          print Message
          print "Opening url"
          video = cv2.VideoCapture("rtsp://username:passwordp@IpAddress:554/axis-media/media.amp")

          print "Opened url"
          fourcc = cv2.cv.CV_FOURCC('X','V','I','D')
          fps = 25.0 # or 30.0 for a better quality stream
          writer = cv2.VideoWriter('out.avi', fourcc,fps, (640,480),1)
          i = 0

          print "Reading frames "
          while threadDie:
                  ret, img = video.read()
                  print "frame number: ",i
                  i=i+1
                  writer.write(img)
          del(video)


          print "Finished capturing video"

Then open the file with a different viewer, prabably in a nother function, like if you like vlc, you can start it and pass the saved file as a parameter. On the terminal, i would do this

vlc out.avi #out.avi is my video file being saved by the function above.

This worked for me on arch linux.

I solved the problem by calling cv2.waitKey(1) in a for loop, I don’t know why it worked but gets my job done, so I didn’t bother myself further.

for i in range(1,10):
    cv2.destroyAllWindows()
    cv2.waitkey(1)

you are welcome to explain.

Sayem2603

I tried your solution and it worked for me – thanks! I did some trial and error and discovered that looping 4 times did the trick for me… or posting the same code 4 times just the same..

Further, I drilled down to:

cv2.destroyAllWindows()
cv2.waitKey(1)
cv2.waitKey(1)
cv2.waitKey(1)
cv2.waitKey(1)

or simply calling DestroyAllWindows and then looping the waitKey() code 4 times:

cv2.destroyAllWindows()
for i in range (1,5):
    cv2.waitKey(1)

Worked as well. I am not savvy enough to know why this works exactly, though I assume it has something to do with the interruption and delay created by looping that code(?)

Matthäus Brandl said, above, that the third waitKey() worked for him, so perhaps it is slightly different on each system? (I am running Linux Mint with 3.16.1 kernel and python 2.7)

The delay, alone, doesn’t explain it, as simply increasing the delay time on the waitKey() does not do the trick. (Also looped print(“Hello”) 1000 times instead of using wiatKey() just to see if the delay that created helped any – it did not.) Must have something more to do with how waitKey() interacts with window events.

OpenCV Docs say: “This function is the only method in HighGUI that can fetch and handle events, so it needs to be called periodically for normal event processing unless HighGUI is used within an environment that takes care of event processing.”

Perhaps it creates an interrupt of sorts in the GUI display that allows the destroyAllWindows() action to process?

J

If you are using Spyder ( Anaconda Package ) there is the problem.

None of the solutions worked for me.
I discovered that the problem wasn’t the functions, but a problem on Spyder really. Try to use a texteditor plus running on terminal and you be fine using simply:

WINDOW_NAME = "win"
image = cv.imread("foto.jpg", 0)
cv.namedWindow(WINDOW_NAME, cv.CV_WINDOW_AUTOSIZE)

cv.startWindowThread()

cv.imshow(WINDOW_NAME, image)
cv.waitKey()
cv.destroyAllWindows()

Here is what worked for me:

cv2.namedWindow("image")
cv2.imshow('image', img)
cv2.waitKey(0) # close window when a key press is detected
cv2.destroyWindow('image')
cv2.waitKey(1)

It seems that none of the above solutions worked for me if I run it on Jupyter Notebook (the window hangs when closing and you need to force quit Python to close the window).

I am on macOS High Sierra 10.13.4, Python 3.6.5, OpenCV 3.4.1.

The below code works if you run it as a .py file (source: https://www.learnopencv.com/read-write-and-display-a-video-using-opencv-cpp-python/). It opens the camera, records the video, closes the window successfully upon pressing ‘q’, and saves the video in .avi format.

import cv2
import numpy as np

# Create a VideoCapture object
cap = cv2.VideoCapture(0)

# Check if camera opened successfully
if (cap.isOpened() == False): 
  print("Unable to read camera feed")

# Default resolutions of the frame are obtained.The default resolutions are system dependent.
# We convert the resolutions from float to integer.
frame_width = int(cap.get(3))
frame_height = int(cap.get(4))

# Define the codec and create VideoWriter object.The output is stored in 'outpy.avi' file.
out = cv2.VideoWriter('outpy.avi',cv2.VideoWriter_fourcc('M','J','P','G'), 10, (frame_width,frame_height))

while(True):
  ret, frame = cap.read()

  if ret == True: 

    # Write the frame into the file 'output.avi'
    out.write(frame)

    # Display the resulting frame    
    cv2.imshow('frame',frame)

    # Press Q on keyboard to stop recording
    if cv2.waitKey(1) & 0xFF == ord('q'):
      break

  # Break the loop
  else:
    break 

# When everything done, release the video capture and video write objects
cap.release()
out.release()

# Closes all the frames
cv2.destroyAllWindows() 

This worked for me in spyder :

import cv2 as cv
cv.namedWindow("image")
img = cv.imread("image_name.jpg")
cv.imshow("image",img)

cv.waitKey(5000) # 5 sec delay before image window closes
cv.destroyWindow("image")

Remember use only cv.waitKey(positive Integer) for this to work

I had the same issue. The problem is that while(cap.isOpened()): loop does not finish so that I added below structure. When video has no frame in the following part, it returns ret values as False. Normally, I put destroyAllWindows command out of loop but I moved it into the loop. It works in my code properly.

while(cap.isOpened()):
 ret, frame = cap.read()  
 if ret == False:
        cap.release()
        cv2.waitKey(1)
        cv2.destroyAllWindows()
        cv2.waitKey(1)

cv2.imshow("the image I want to show ",img)
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.waitKey(1)  # to close the window.

The above code worked well for me.
I’m using Mac and python 3.7 .

Close the terminal, later close the window, it worked for me in Visual Studio Code in Windows; I made a task to compile and run the executable in the terminal, the program used my webcam to capture video and display it in a QT window, when I clicked the close button it didn’t close, it reopened itself again and continued with the program until I closed the terminal and later could close the program window without it reopening again.