Attached Link: http://www.renderosity.com/mod/forumpro/showthread.php?message_id=1793847&ebot_calc_page#message_1793847

If the map does have some graduation, you might be able to use one of the "Gamma", "Bias", or "Gain" nodes. I suspect you'll need to setup the Vue equivalent of the node network in the linked post (make a meta-node if you need to apply to several maps). This is a very simple implemenation of [Box blur](http://en.wikipedia.org/wiki/Box_blur).

With (many) more nodes you could get close to implementing Gaussian blur, but doing this in an image editor would be more time efficient.