Section: New Results

Editing and Modeling

Figure 11. Left: our low-cost depth-from-focus acquisition setup. Right: result of our reconstruction algorithm for the sample shown in the middle image. The width of grooves are about 500 micrometers.

Depth from focus stacks at micrometer scale

In this work we designed a low-cost acquisition setup and a new algorithm for the digitalization of micro reliefs. The setup is based on a common digital camera equipped with a special assembly of different lenses designed to enable a ×2 magnification factor with a very shallow depth of field (fig. 11). A micro-metric motor rail allows us to acquire dense focus stacks with depth information that can be reconstructed through image processing and analysis techniques. To enhance the accuracy of this reconstruction step, we designed novel focus estimators as well as novel focus-point analysis algorithms exploiting novel 3D invariants. Our initial results show that we are able to reconstruct depth maps with sub-step length accuracy.