Thumbnails are not generated in Win 11

I am generating my images using OpenCV from hdri using tonemapping methods. Those images are successfully generated, but every time I browse the directory I can’t see a Windows generated thumbnails for them. Can’t find out what can be a problem. My Windows and Explorer set up is OK, no issue here, so it must be sth with my cv2.imwrite method, or maybe file rights management. Please help!

PS. If I select all generated .jpgs and press ENTER, thumbnails are correctly generated.

lack of immediate reaction by Windows Explorer is beyond the scope of OpenCV.

Hit F5 a few times or open the folder in a new window.

if you “select all generated .jpgs and press ENTER”, they should all be opened in the associated viewer program, aside from whatever Windows Explorer decides to do about it.

your viewer program may or may not modify thost files to add an explicit thumbnail in the file itself.

Windows Explorer can use those, but it can also generate its own thumbnails and cache them.

It was a problem of environment, nothing related to Python or OpenCV. I tested it on other PC and it works.