In this chapter, we used Qt to build a desktop application for image viewing, from scratch. We learned how to design the user interface, create a Qt project from scratch, build the user interface, open and display images, respond to hotkeys, and save a copy of images.
In the next chapter, we will add more actions to the application to allow the user to edit the image with the functions provided by OpenCV. Also, we will add these editing actions in a more flexible way by using the Qt plugin mechanism.