Reflectance from Photographs

Here's the problem: we've got an object of known geometry in a known location at a known time. The problem is to get the color and reflectance from a collection of those photographs. That's a large part of the intellectual merit of this proposal we are working on. The photograph shows such an object in my driveway on a Friday afternoon. The cylinder is 12 inches high and has a diameter of 6 inches. We painted it with matte and semi-gloss spray paint. The painted portions will allow us to calibrate our results with surfaces of known color and reflectance.