Does bouncing to Quicktime alter image quality

Hi Guys

I was just wondering when selecting the bounce to Quicktime option does Protools degrade ,alter or compress the video in any way or is it a simple pairing of the audio with the video track?

I have a unique situation where we might possible need to layback the audio mix to finalised online pictures within Protools in this case probably a Pro Res 422 HQ file.

I am concerned that Protools may alter the image quality as I am used to providing finalised audio for the online stage not the other way around. Any advice on this would be of great assistance.

Does bouncing to Quicktime alter image quality