Don't you think you should be posting directly the appropriate forum by now as you're classified as a senior member with 258 posts.
I would guess that some of the members here will only visit the forums that hold their particular interests so you might get better expert advice , quicker.
To answer your question, it depends what is causing the pixelation. If the pixelation occurs on a standalone DVD player but not on the computer then a file comparison might well state that the 2 copies are the same having done a bit-by-bit comparison.
If it occurs on the PC, when reading from the DVD , then again a comparison might well succeed as file operations (copy,compare etc) on a HDD or optical device will handle re-reads whereas a player (PowerDVD for example) will stutter as it's not getting the smooth continuous flow of data that it expects.
I guess really there's no definitive answer to your question.
Hope that was helpful.