If you had the "scrot". You don't need any else!
In console use this cmd: which scrot. If "scrot" existed in your system you will see this message /usr/bin/scrot or /usr/local/bin/scrot ... or something like those
Now you can learn "howto use scrot"
For exam: If you like to crop an rectangular region on the desktop. You can use: scrot -s /root/yourimage.png -> Enter. Then drag your mouse on/over your desired region.
Your image will be placed in /root
May be interesting?