Is the current method the best one (i.e. the one that produces a perfect lossless dump)? Is there a way to make PS2 raw dumps? Is there a method to calculate factory write offset?
I have many PS2 games here and I'd like to dump them only once; if a better method will be discovered I will have to redump everything.
Another question: is there a way to check PS2 images? I mean the equivalent of CdMage for DVD images. I want to be sure that the images I submit are 100% free from errros and corrupted sectors.

To answer your questions: DVD's don't have an offset, so no need to correct anything.. all the relevant data is copied in 2048 bytes/sector user mode(except for DNAS data, which is left out.. you can use a homebrew tool and load your disc on your ps2 to get the DNAS data.. you can put it in comments).. and there won't be any errors or corrupted sectors if the dvd drive doesn't give you any read errors on the disc, so no need to scan anything.. you can also check on emule if there are any sources that match your ed2k checksum, so you can be absolutely sure that you have a proper image (though this isn't really needed)..

Thanks! I'll start the back-up process as soon as I finish my CD Based collection!