Basically, Blood Bath is a weird little black-and-white vampire horror flick from 1966, produced by Roger Corman. Parts of it look really, REALLY beautiful though, and that is because they've been taken from another film entirely, a Yugoslavia-based crime thriller called Operation Titian. That film turned out to have a re-cut version with additional footage made for the US as well, called Portrait in Terror, and Blood Bath itself got re-cut with additional footage again as Track of the Vampire.
This release has all four films in it, one with an HD transfer and three even with new 2k transfers, and there is a wealth of extras, including a feature-length documentary about how these films came to be.
It also looks pretty spiffy, so check out this gallery of shots. Click on the edge of the pictures to scroll through them, or at the center of each to see a bigger version.