InitRech 2015/2016, sujet 5

Summary

With the technology such as augmented reality, researcher are confronted against new problem like image processing, facial recognition system and 3D shape recovery.
this paper show a newer method in real time to calculate a 3D deformable shape with a monocular video sequence.
Firstly authors explain what is the context and what did we wonder to resolve this subject. Next, they describe algorithms already use in 3D recovery for non rigid shape and their assets of this 4 four technologies :

• Mechanical models
• Mass-spring systems
• Learned non-rigid models
• Parametric models

In addition historic of previous research and their contribution are given in term of efficiency to compute image processing and to recover a 3D elastic shape with one point of view.
After many assumption they succeed to minimize in a non-linear problem for non-rigid shape, result this equation:

Knowing that, m is a point of our image m = (x,y), P* the matrix projection of the view and m* is the projection of the point (x*,y*,z*) in our image.
Thanks to energy equation to characterize the 3D deformation:

They resolve this problem as an energy minimization problem accounting for a non-linear elastic model constrains to a static view with the knowledge of his matrice projection.
To continue they use tool like Gauss Seidel and Euler to solve this problem on compute. In the last part they describe tests and compare to algorithm already existing and what is the process to solve self-occlusion handling.

Main Contribution

With help of precedent studies, researcher find an other technique more efficient in 3D recovery with a monocular view. With this new algorithms and the new way to optimise, now they are able to recover a occlude area if we know the shape. This is a real impact in medical analysis, they realize test in an invasive liver surgery. These methods rely on a combination of a stereo estimation of organ motion and on biomechanical models to characterize the elastic behaviour.

Applications

The purpose of this paper, is to help medecin in many analysis of surgery, to isolate the part needed before processing on it. Moreover in military task, to reshape in full body humanoid behind a rock or whatever obstacle.
In aeronautics or space advanced to pilote automatically, take off and landing with a camera, an artificial intelligence to drive craft or whatever. Another way is, with a 3D modeler, to create a realistic environment and analyse all objects in scene to premeditate movements and deformations, with the physical characteristic of the 3D modeling, that can give us probability of material resistance.

In gaming, that will give us an another way to interact with people, we can imagine game uses this technology with oculus rift with networking that could be awesome.
To conclude, i believe in the dream of Asimov robot’s, and reality augmented analysis is a next step forward.