There are commercial VIs for driving Matrox Meteor2 frame grabber. I guess they are based on Matrox Imaging Library.
http://www.alliancevision.com/us/products/software_alv/meteor2/fr_meteor2.htm
Instead of using the image processing function of Matrox MIL you could also use the functions provided with IMAQ Vision. Both libraries provide almost the same functionality but with IMAQ Vision your are already in the "LabView domain".
As your question is quite old: Did you found a free one? I need to make some frame grabbing with Matrox Orion and would like to stick to the "LabView domain".