How To Capture High Resolution Screen Shots In Linux

Have you ever needed to capture a screen shot of something in Linux and 72dpi was not high enough resolution. I recently found myself in this situation trying to capture some images of the great screen savers that come with most Linux distributions. The way you do this is easier than it first appears. First, you must have an ssh server running. This is running by default on most of the newer Linux variants. You must also have ImageMagick installed and working. ImageMagick is great for manipulating images from the command line. There are binary packages for ImageMagick for most of the major distributions or you can build it yourself by getting the source code.

Step 1: Connect from a separate PC via ssh.

You could also log in to a second tty session (i.e. CTRL+ALT+2), but I am trying to capture a screen saver so I don't want to actually press any other keys once the screen saver is running or I will exit back to the desktop.

ssh username@servername

Step 2: Use the import command to capture your screenshot.

You need to make sure you specify the main display and the root window to capture the main screen. Also, the density option will allow you to capture at a higher dpi than normal.

import -display :0 -window root -density 600 screen.png

That's it! Enjoy your hi-res screen shots.