I’m writting some game reviews and movie reviews, every now and then and therefore being able to capture a fullscreen running program like let’s say mplayer or vlc or some full screen running game is something I really need.
The usual PrtScr button which normally works to prepare screenshots in GNOME or KDE, however is not working if the root window handler is being passed to a different program than the Window Manager and pressing it while inside of many older programs or applicationsdoes not produce a print screen of the current screen.
Anyways I found a hack to this using the good old ImageMagick – import command line screenshotting program.
To take a screenshot of a certain program run from gnome-terminal or konsole using import cmd its possible to use a quick one liner which will take a snapshot of the root Window the started program will use.
Let’s say you want to make a screenshot of the entry screen of the FreeDOOM (DooM 3d shooter classical game arcade free Software Alternative).
Launch gnome-terminal or konsole , xterm , depending on the GUI environment you use and issue the commands:
debian:~$ ( sleep 15; import -window root my_desired_screenshot_name.png ) &
The first command will launch import after a sleep of 15 secs and therefore will screenshot the active window which will be at focus after 15 seconds, where the & sign will background it and the second one will launch FreeDooM . You will have to wait for a certain secs and switch to the exact screen you will want to screenshot.
If you want to screenshot some game scene that will appear in 20 minutes change above sleep 15 cmd to be to something like sleep 180
That method can be used for screenshotting any other program running on fullscreen, the method is a bit inflexible as you will have to adjust a timing but it works fine 😉