Use VitualDubMod with VOB import support
http://www.videohelp.com/tools?tool=72#comments
put in ya dvd, do File/open video file
browse to the dvd drive.
choose the VideoTS folder, then you will see lots of VOBS which contain all of the chapters of the DVD.
Choose the chapter, and double click
once the chapter has loaded, use the scroll bar to select the image you want to rip.
Press CTRL+1
open up photoshop, click file/new
then EDIT/PASTE
Note that the biggest image you can take from an NTSC dvd is this ratio 720x480
use the DEINTERLACE filter in photoshop to get rid of the jagged lines, then crop to your desired size.
That should do what you want it to do.
Nick