Template:Hover
This template displays a default image, then substitutes another image when the reader hovers over it (e.g. if visual users place their mouse over the image). Works best when the images are the same size, but they don't have to be.
{{hover|Roster-blank.jpg|Roster-rahman.jpg}}
(Place pointer over image to see effect.)
Additional Options
Usual image options are supported (link=, custom pixel width or height, alt text, etc.)
{{hover|Roster-blank.jpg|Roster-rahman.jpg|link=Roshanara Rahman}}