In this chapter, you learned how to integrate a third-party library with each desktop OS (Windows, Linux, and Mac OS). We chose the OpenCV library, which has been included in a custom Qt Designer plugin and which can display a live preview of your image processing result in Qt Designer. We created an image-filtering application that can open pictures, apply filters to them, and save the result on your machine.

We had a good look at how you can integrate third-party libraries and how you can make a Qt Designer plugin. In the next chapter, we will push things forward by making the image-filter application ready to load filter plugins that could be implemented by third-party developers. To make things even cooler, we will cover the Qt animation framework to make the image-filter more spectacular.