iDVD Output Quality

I am a new user to iMAC, with Mac OS version 10.6.1, 3.06 GHz, 4GB ram, 1TB.
iDVD slidshow output is degraded. Poor quality.
I want to create DVD's with slide show output quality as good as my iPhoto input quality.
I've done the iDVD setups like professional quality, frame rate, aspect ratio, etc.
I hope I have missed something. iDVD should do this for me!
As a last resort, is there an app other than iDVD that will create professional quality DVD's?
Final Cut Studio is not an option. Way too expensive, $1000.00.