Why cv2.namedWindow is not works?-CodePudding

I try start my code, but process finishes on step with method cv2.namedWindow (without any errors). Do you have any suggestions, why it could be so?

import cv2


image_cv2 = cv2.imread('/home/spartak/PycharmProjects/python_base/lesson_016/python_snippets/external_data/girl.jpg')


def viewImage(image, name_of_window):
    print('step_1')
    cv2.namedWindow(name_of_window, cv2.WINDOW_NORMAL)
    print('step_2')
    cv2.imshow(name_of_window, image)
    print('step_3')
    cv2.waitKey(0)
    print('step_4')
    cv2.destroyAllWindows()

cropped = image_cv2
viewImage(cropped, 'Cropped version')

P.S.: Also I erased UBUNTU , and installed Fedora. Instead Pycharm, check programm on VS code. But nothing changes. I changed location for picture (girl.jpg) to directory with python document. But program stops on step1 and waiting something. test_other_direct

CodePudding user response：

The code completes all 4 steps for me

I think there is a problem with the image path which you took

The function cv2.namedWindow creates a window that can be used as a placeholder for images and trackbars. Created windows are referred to by their names If a window with the same name already exists, the function does nothing.

CodePudding user response：

I do think the function cv2.destroyAllWindows This function is deallocating some needed gui elements, I would guess. So calling this multiple times will produce some trouble.

import cv2

image_cv2 =  cv2.imread('foo.jpg')
def viewImage(image, name_of_window):
    print('step_1')
    cv2.namedWindow(name_of_window)
    print('step_2')
    cv2.imshow(name_of_window, image)
    print('step_3')
    cv2.waitKey(0)
    #print('step_4')
    #cv2.destroyAllWindows()
    

cropped = image_cv2
viewImage(cropped, 'Cropped version')
#e.g. better usage at the end of the code or section 
cv2.destroyAllWindows()