In this chapter, we created a new desktop application, the Gazer, for capturing, playing, and saving videos from our cameras. For home security purposes, we also added a feature for motion detection. We built the UI with Qt and developed the video processing features with OpenCV. These two parts were integrated into our application organically. In the development of this application, we learned about how to use the Qt layout system to arrange the widgets on the UI, how to use multithreading technology to do slow work in a thread that differs from the main UI thread, how to detect motion using OpenCV, and how to send notifications to our mobile phone via IFTTT by firing a HTTP request.
In the next chapter, we will learn how to recognize faces in images or videos in real time, and we will build an interesting application so that we can put funny masks on the detected faces...