Getting GUI to open up


I have stated signature from the terminal (on a linux machine) and no GUI opens.

The following however happens in terminal when I type command signature:
spatel@sparx:~$ signature
hacked script signature, version 2.02a
the following options can be used:

-h this help text
-v show version number
-d show debugging output
-wisdom FILE use FFTW wisdom file
-g start in GUI mode
-b FILE start in batch mode and screen project FILE
-c start in creation mode. creation options are
explained below

creation mode options:
-space NAME set project space name (w/o trailing .ems)
-film NAME set project / film name
-source FILE specify micrograph image file
-template FILE specify template file
-margin DIST margin masked around the image boundaries in pixels
-resize SIZE resizing factor used in image decimation
-partsize SIZE particle size in Angstrom
-partdist DIST particle distance in Angstrom
-pixelsize SIZE pixel size in Angstrom
-lcf-thresh THR correlation map threshold for particles

What am I not doing ?