I am not sure I recall an answer to this question. I too am looking for
a screen capture utility for a Debian-based system. Text captures are
easy -- I am a long-time UNIX user and sys-admin. In Solaris there is an
xgrab utility that allows you to define the upper-left and lower-right
corners, then a time countdown to capture. Options included capturing
the outside or inside of the active window at the end of the countdown.
I need this same functionality under Debian -- needed to provide captures
for trouble reports, help and manual documentation, and design documents.