fbcat (take screenshots of the framebuffer console)

fbcat takes a screenshot using the framebuffer device and stores it in a
PPM file. Also provided is a fbgrab command, which takes PNG screenshots
and supports several useful options (such as changing consoles).

The following visuals are supported: TRUECOLOR, DIRECTCOLOR, PSEUDOCOLOR,
STATIC_PSEUDOCOLOR, MONO01, MONO10.

On the SlackBuild author's system, fbcat runs about 3x as fast as fbdump.
