In this chapter, we remade the desktop application for image viewing that we built in Chapter 1, Building an Image Viewer, to make an image editor application. Then, we added a simple editing feature to blur images. At the same time, we learned about how to install and set up OpenCV for Qt applications, the data structures related to image processing both in Qt and OpenCV, and how to process images using OpenCV.
Afterward, we learned about the plugin mechanism of the Qt library and abstracted out a way to add editing features to our applications in a more flexible and convenient way as plugins. As an example of this, we wrote our first plugin to erode images.
Then, we moved our attention to the OpenCV library to discuss how to edit images like a pro—we made numerous plugins to edit images, to sharpen images, to make cartoon effects, to rotate, to execute affine...