$ python main.py
Traceback (most recent call last):
File "main.py", line 971, in
cv2.createTrackbar(TRACKBAR_IMG, WINDOW_NAME, 0, last_img_index, set_img_index)
cv2.error: OpenCV(3.4.5) /io/opencv/modules/highgui/src/window_QT.cpp:1223: error: (-27:Null pointer) Max value of the slider must be bigger than 0 in function 'addSlider2'
$ python main.py Traceback (most recent call last): File "main.py", line 971, in
cv2.createTrackbar(TRACKBAR_IMG, WINDOW_NAME, 0, last_img_index, set_img_index)
cv2.error: OpenCV(3.4.5) /io/opencv/modules/highgui/src/window_QT.cpp:1223: error: (-27:Null pointer) Max value of the slider must be bigger than 0 in function 'addSlider2'