Rendering Uncompressed - Still looks worse than original..

I'm rendering a timelapse video out of a number of still shots.

I'm using VideoMach because it is the best software I've found so far (if you know something better, I'm all ears).

I tried rendering Full-Frame uncompressed, but the file limit is 2GB for some reason.

So, I'm using Xvid. I've set everything to unrestricted and have tweaked the settings (as best as I know how) a thousand times.

However, there is still a degradation in quality.

Here is an example:

This is the original.



This is an image taken from the video encoded.



This is at 250%. I know that at 100% you can't tell the difference, but I'm picky and I don't want to delete the original files without having something that could re-create the same quality if need be.

If anyone can tell me what I'm doing wrong, I'd very much appreciate it.

Thank you.