I'm trying to create a depth map from real-time video, and as you can see, a gray screen appears when cv2.imshow is used, and a somewhat visible phenomenon appears when plt.imshow is used. I would like to know the cause of why only a gray screen keeps appearing when I use cv2.imshow. I thought it was camera calibration, but as far as I know, the camera on the gazebo doesn't have to be calibrated separately.