Versioning in Image Formats:
For an excellent overview of the issues around using tags to embed information (including version information) into images, please see here: http://www.tasi.ac.uk/advice/delivering/faqtagging.html, where TASI (The Technical Advisory Service for Images) cover all of the present options for how content creators can using tagging to identify their images.
.jpeg/.jpg and .tiff
As outlined in the page linked to above, EXIF (http://en.wikipedia.org/wiki/Exif) is a common format used for jpeg and tiff formats to store information with an image file.
It is easy to edit the information in images by downloading a small plug-in for windows: Microsoft Photo Info 1.0 (external link). Below is a screenshot of the descriptive fields available in this editor:
The framework recommends using the 'Description' field to write a free text description of the version status.
Recommendations:
Filename is a particularly
useful and reliable opportunity to make a version comment with images,
as embedding information in image files is non-standard and may not be
easily accessed by all. With images it is particularly important to pass
on version information to a repository when depositing such files with
them.