Accurate and automatic three-dimensional modelling of urban scenes from digital photographs

Project : Accurate and automatic three-dimensional modelling of urban scenes from digital photographs

Establishments: laboratoire Imagine, l'Université Paris Est, l'ENPC/CSTB.

Research themes: Information Technologies and Sciences

For the duration of: 2009/2011

Link: http://imagine.enpc.fr/ or http://recherche.ign.fr/labos/matis/

Descriptive : The purpose of this project consists in automatically creating 3D urban models from digital photographs. These models must simultaneously be accurate and "semantized", i.e. "understood and recognized" by the machine in terms of geometry (plans, columns, etc.) and function (doors, windows, etc.).

The first phase of the project focused on the geometric aspect.

Two types of representations combined into a single model:

• meshing to describe irregular items (statues, ornaments, etc.);
• geometric primitives to represent regular items (walls, columns)

An initial step segments three-dimensional meshed surfaces into distinct regions. A second step provides a detailed 3D description of the scenes by analysing each previously segmented element and associating it either with a primitive, or with a more accurate irregular mesh.
The mathematical tools used take into consideration high-level bias specific to urban models.  

These tools are :

• Markov fields optimised by graph cuts;
• jump diffusion processes.

A second phase has been scheduled and shall focus on the functional aspects of 3D models.