Tel-Aviv University - Computer Science Colloquium

Sunday, Jan 8, 2006, 11:15-12:15

Room 309
Schreiber Building


Ronen Basri

Weizmann Institute


3D reconstruction by example



Assume we have knowledge of the shape and appearance of several example 3D

objects, all from a specific class. How can this knowledge be used to

recover the 3D shape of a novel object of the same class from a single view?


In this talk I try to answer this question by presenting two new methods for

3D reconstruction from single images. The first method uses examples of

feasible appearance-to-depth mappings, extracted from a pre-collected set of

3D objects, to produce reconstructions of novel objects belonging to a

variety of classes (e.g., hands, human figures). On-the-fly example

synthesis scheme is used to cope with unknown viewing conditions and large

example sets. The second method focuses on human faces, allowing 3D

reconstruction using only a single reference model of a different person's

face. Assuming Lambertian reflectance and rough alignment of the input image

to the reference model, this method seeks shape, albedo, and lighting that

best fit the image while preserving the rough structure of the model. We

demonstrate this approach by providing accurate reconstructions of novel

faces overcoming significant differences in shape due to gender, race, and

facial expressions.


Joint work with Ira Kemelmacher and Tal Hassner.