$ sudo apt-get update
$ sudo apt-get install kdegraphics-thumbnailers 

kdegraphics-thumbnailers is installed in your system.

Make ensure the kdegraphics-thumbnailers package were installed using the commands given below,

$ sudo dpkg-query -l | grep kdegraphics-thumbnailers *

You will get with kdegraphics-thumbnailers package name, version, architecture and description in a table

kdegraphics-thumbnailers package basic information: