Code to mix three images in one image

[Adnan1986]

Hello,

Thanks for your wonderful works, I know it is a long time but I am just curious how you drew the first figure of your paper which you have used three images with different superpixels and combined all of them in one image.
Did you use MATLAB or LATEX command to draw it?
I do appreciate it to help me how I can do that.

Many thanks