14 Feb 2011
"The surface / surf plot in MATLAB can visualize data in 3D. When I took a course in grad school on statistical image processing, I saw a very interesting plot where data is shown as a surf plot and underneath, on the ground or x-y plane, an image is shown. The pixels of the image corresponded to the points in the 3D surface and gave some extra information about the each point, sort of like an image-based version of surfc or a 3D version of plotting over an image background. I always wanted to know how to make that plot but rather than asking the prof who made it (as one is supposed to after paying tuition), I decided to figure it out on my own (thus proving why I was never good at accounting). It took some experimentation but I finally figured out how this type of plot is accomplished. In this tutorial, I will show how to do this and how to make it so that the surface plot and the image can use different colormaps, getting around the restriction that MATLAB only has one colormap per figure. In effect, this will simulate multiple colormaps."