All examples of this tutorial are either partly or wholly copied/borrowed from opencv webpage. The idea of this repository is to set a path for others to follow. It is not a comprehensive list of functionalities of opencv.
Merge two images, linear_blend.cpp is a simple program to demonstrate merging of two images. Both images need to be of same size. Once you build the applicaiton, try linear_build image_1.jpg image_2.jpg. Output will be written to ouput.jpg in the location you are invoking.