As to the information on image processing in GRASS, please try to read the
article in the GRASS Clippings (Vol. 6, No. 2, Page 10): Image Processing
in GRASS. -- by Hong C.Zhuang
Or you can access the ftp server:
Promp> ftp moon.cecer.army.mil
Name: ftp
Password: personal e-mail address
cd grass4.0/documents/tutorials/4.0
Type i
get imagery.ps.Z
I hope it works. Good luck to you.
John Wu