Using this plugin you can add a interactive zoom hover effect on a image. This plugin offer a shortcode to generate the effect. This plugin using a jquery plugin Magnify by by Tom Doan.
Shortcode Example
[image_magnify src="NORMALL_IMAGE_URL" src_big="BIG_IMAGE_URL" w="WIDTH_OF_THE_IMAGE" h="HEIGHT_OF_THE_IMAGE" alt="ALT_TEXT_OF_IMAGE" clas="CSS_CLASS" /]
This plugin is available for download to be used on your WordPress self-hosted installation.