OpenCV window always on top

Question

Is there a way to set a OpenCV window to be always on top? And can i remove the minimize and close button from my window? Thank you.

Answer 1

You can use: cvGetWindowHandle() to obtain Widows handler. Then using regular windows API you can do anything you like

Answer 2

I found the best solution posted in comments here: Python OpenCV open window on top of other applications

Simply add the command below after opening a window, e.g.

cv2.namedWindow('img_file_name', cv2.WINDOW_NORMAL) # Creates a window
os.system('''/usr/bin/osascript -e 'tell app "Finder" to set frontmost of process "python" to true' ''') # To make window active

Use "python" in lower case. Using "Python", as I found in some answers, gave me an error:

21:62: execution error: Finder got an error: Can’t set process "Python" to true. (-10006))

Answer 3

cv2.namedWindow('CCPDA')
cv2.resizeWindow('CCPDA', 200, 200)
hWnd = win32gui.FindWindow(None, 'CCPDA')
win32gui.SetWindowPos(hWnd, win32con.HWND_TOPMOST, 0, 0, 0, 0,
                      win32con.SWP_SHOWWINDOW | win32con.SWP_NOSIZE | win32con.SWP_NOMOVE)

Answer 4

You can use setWindowProperty to set an OpenCV window on top with the property WND_PROP_TOPMOST.
This works with OpenCV 3.4.8+ and 4.1.2+.

E.g. in python:

import cv2, numpy as np
window_name = "Top Window"
cv2.namedWindow(window_name, cv2.WINDOW_NORMAL)
cv2.setWindowProperty(window_name, cv2.WND_PROP_TOPMOST, 1)
cv2.imshow(window_name, np.full((480,640,3), (234,183,39), dtype=np.int8))
cv2.waitKey(0)

The above python code should create a foreground window:

Answer 5

I found that all I needed to do was set my main window to fullscreen then back to normal.

    #!/usr/bin/env python
    import cv2
    import numpy

    WindowName="Main View"
    view_window = cv2.namedWindow(WindowName,cv2.WINDOW_NORMAL)

    # These two lines will force your "Main View" window to be on top with focus.
    cv2.setWindowProperty(WindowName,cv2.WND_PROP_FULLSCREEN,cv2.WINDOW_FULLSCREEN)
    cv2.setWindowProperty(WindowName,cv2.WND_PROP_FULLSCREEN,cv2.WINDOW_NORMAL)

    # The rest of this does not matter. This would be the rest of your program.
    # This just shows an image so that you can see that this example works.
    img = numpy.zeros((400,400,3), numpy.uint8)
    for x in range(0,401,100):
        for y in range(0,401,100):
            cv2.line(img,(x,0),(0,y),(128,128,254),1)
            cv2.line(img,(x,399),(0,y),(254,128,128),1)
            cv2.line(img,(399,y),(x,399),(128,254,128),1)
            cv2.line(img,(399,y),(x,0),(254,254,254),1)
    cv2.imshow(WindowName, img)
    cv2.waitKey(0)
    cv2.destroyWindow(WindowName)

Answer 6

The simplest way I found to solve this for anyone looking back was just these two lines. It's like the other answer by Gugile but there's no need to have a seperate line creating the named window first.

cv2.imshow('window_name', img)
cv2.setWindowProperty('window_name', cv2.WND_PROP_TOPMOST, 1)

Answer 7

for me this work fine in macOS, I think that it's will work well in another os

destroyWindow( "windowName" );
namedWindow( "windowName", WINDOW_NORMAL );
moveWindow( "windowName", posx, posy );
imshow( "windowName", frame );

this repeat in loop, the sequence are:

1. destroy window, this force to create new window
2. declare new window
3. move window at position that you want, for example last position
4. show window