Looking to easy workflow to export marked frames from two in sync video tracks to images (Sony Vegas but open to other editors. more info inside)

So, I've been doing this thing where I run comparison between the TV airing and Bluray release of Television episodes.

My current method is using difference fields. I play both versions on top of each other with a difference filter which highlights the differences in the preview window. I then place a marker in the timeline to take note of each difference.

EXAMPLE
TV
BD
Difference

The only thing I'm missing is to easily export the marked frames to images.
The last time I did this I wound up typing each marked frame number into a videoplayer and screencapping. NEVER AGAIN.
There's gotta be a better way.

Thank you.