The code for this tutorial is here
Opencv provides are useful, but limited, method of building a GUI. A much more complete system could be acheived using pyqt.
The question is, how do we display images. There are quite a few possible routes but perhaps the easiest is to use QLabel since it has a setPixmap function. Below is some code that creates two labels. It then creates a grey pixmap and displays it one of the labels. code: staticLabel1.py
from PyQt5.QtWidgets import QWidget, QApplication, QLabel, QVBoxLayout
from PyQt5.QtGui import QPixmap, QColor
import sys