ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.
One of a set of tools we're offering as a way to say thank you for being a part of the community.
Do a search for vob to jpeg, one example which i have never used is:
http://www.dvdvideosoft.com/products/dvd/Free-Video-to-JPG-Converter.htm#.UoTmHI1V4xI
It might make it easier as opposed to screen shots ... The original slideshot photos are downsized when imported into a .vob format.
Hope that helps.