Slow scanning speed of scanner

I am using HP Scanjet G2410 Scanning software TWAIN interface. I have
to scan 500 nos. of signature from the signature cards then crop the
signature and save to the software. But I am unable to crop the
signature in the fist scan because it is too small to see the
signature so I have to enlarge again so another scanning and then I
can crop if there is any option that I can crop form the fist scan
itself? In-between I have to change the color to B&W and resolution to
100. Now I am able to do only100 Nos. of signature scanning per day
because of these problems is it possible to set this setting as
default setting? Because I have to do the same repeatedly Plz help me
out.

Naveen Chacko

Mob. 094470 65556