Surface Depth Hallucination
Surface depth hallucination offers a simple fast way to acquire albedo and depth for textured surfaces that exhibit mostly Lambertian reflectance. We obtain depth estimates entirely in image space, and from a single view so there are no complications that arise from registering texture with the depth obtained.
The user simply takes two photos of a textured surface from an identical position parallel to the surface; one under diffuse lighting conditions as might be encountered on a cloudy day or in shadow, and the other with a flash (strobe). From these two images together with a flash calibration image, we estimate an albedo map. We also estimate a shading image primarily from the diffuse lit image capture. We develop a model that relates depth to shading specifically tailored for textured surfaces with relatively little overall depth disparity. By applying this relationship over multiple scales to our shading image, we arrive at a per pixel height field. Combining this height field with our albedo map gives us a surface model which may be lit with any novel lighting condition, and viewed from any direction. Provided we have a suitable exemplar model, our method can also work from a diffuse lit image alone by histogram matching it with the albedo and shading images of the exemplar model further simplifying our data capture process.
We validated our approach through experimental studies and found that users believed our recovered surfaces to be plausible. Further, users found it difficult to reliably identify our synthetically relit images as fakes. Details of our method, and the results of our validation are to be published in SIGGRAPH 2008