Learning Graphical User Interfaces

In Chapter 2, An Introduction to the Basics of OpenCV, we learned the basic classes and structures of OpenCV and the most important class, called Mat. We learned how to read and save images and videos and the internal structure in the memory of images. We are now ready to work with OpenCV, but, in most cases, we need to show our image results and retrieve user interaction with our images using a number of user interfaces. OpenCV provides us with a few basic user interfaces to facilitate the creation of our applications and prototypes. To better understand how the user interface works, we are going to create a small application called PhotoTool at the end of this chapter. In this application, we will learn how to use filters and color conversions.

This chapter introduces the following topics:

• The OpenCV basic user interface
• The OpenCV Qt interface
• Sliders and buttons
• An advanced user interface – OpenGL
• Color conversion
• Basic filters