This chapter has shown several different types of image-processing filters that can be used to generate various cartoon effects: a plain sketch mode that looks like a pencil drawing, a paint mode that looks like a color painting, and a cartoon mode that overlays the sketch mode on top of the paint mode to make the image appear like a cartoon. It also shows that other fun effects can be obtained, such as the evil mode that greatly enhances noisy edges, and the alien mode that changes the skin of the face to appear bright green.
There are many commercial smartphone apps that perform similar fun effects on the user's face, such as cartoon filters and skin-color changers. There are also professional tools using similar concepts, such as skin-smoothing video post-processing tools that attempt to beautify women's faces by smoothing their skin while keeping the edges and non-skin regions sharp, in order to make their faces appear younger.
This chapter shows how to port the app from a desktop application to an Android mobile app, by following the recommended guidelines of developing a working desktop version first, porting it to a mobile app, and creating a user interface that is suitable for the mobile app. The image-processing code is shared between the two projects so that the reader can modify the cartoon filters for the desktop application, and by rebuilding the Android app it should automatically show their modifications in the Android app as well.
The steps required to use OpenCV4Android change regularly, and Android development itself is not static; so this chapter shows how to build the Android app by adding functionality to one of the OpenCV sample projects. It is expected that the reader can add the same functionality to an equivalent project in future versions of OpenCV4Android.
This book includes source code for both the desktop project and the Android project.