Replace image urls(absolute instead of relative) by using filter in single page

Question

I'm using a plugin called Foliopress WYSIWYG. While using this plugin, images found in the_content loop using relative image path instead of absolute paths. So all the feed images looks broken.

This plugin stores images in http://mysite.com/images folder instead wp-content/uploads folder. So i would like to use filter to replace relative path.

I mean if any img src file looks like /images/2010/03/example.jpg then it should be filtered and replaced with http://mysite.com/images/2010/03/example.jpg

Can anyone give me the snippet? Thanks