Eric Bittar

Hierarchical Tracking of Intra-Cell Structures in 4D Images

We present in this paper the hierarchical extension of 4DReAM, a tracking framework based on a deformable model, and how we apply it in cell biology, where the use of auto fluorescent proteins and confocal microscopy enables the acquisition of the volumetric content of live cells through time sequences of 3D images (also called 4D images). Thanks to a hierarchical paradigm, 4DReAM allows interactive visualisation and analysis of the evolution of structures enclosed one in another, at different levels in the cell, such as nucleus, nucleoli, and proteins. The usefulness of our approach is illustrated on experimental results from confocal 4D images, which bring new light to the space-time reorganisation of intra-cell structures.

LeBonGeste: basketball training by entertaining

This paper describes LeBonGeste, a device consisting of a basketball basket equipped with sensors, actuators and computers to create a so called augmented basket. It is used to train beginner players to the free throw by helping them to achieve the right stance. Thanks to the Kinect depth-sensor, the system delivers realtime feedback to the player. LeBonGeste has been showcased two times indoor and outdoor using different communication channels for feedback: visual (screen or LED strips) and audio. Developed as an interactive installation for training by entertaining, the system will be tested soon on basketball courts with experienced players.

Incremental plane-based reconstruction and exploration of buildings in old postcards

We present an approach for 3D reconstruction of a city model over the time from a collection of old postcards of the city of Reims. The planar structure of the buildings facades constraints the dense reconstruction of the city. We use a feature matching technique while proposing the registration of facades in the images and there use for the reasoning about there visibility in the images. This system is semi-automatic, it requires a user control in the complicated case where no matches are found to link an image to the dataset. The image data set is sparse and the urban space evolves over time.

Suivi hiérarchique de structures intra-cellulaires dans des images 4 D

Thanks to the use of autofluorescent proteins, cell biologists are now able to observe and study the evolution of the volumetric content of live cells through time sequences of 3D images (also called 4D images). We present in this paper 4DReAM a tracking framework based on a deformable model, and how we apply it in cell biology to understand, describe, explain, in addition to interactively visualize and analyze the evolution of structures enclosed one in another, at different levels in the cell: proteins, nucleoli and nucleus. This deformable model, defined as a triangulated mesh, can automatically adapt its topology to fit the splits and merges of the biological objects. The usefulness of 4DReAM is illustrated on experimental results from different 4D images acquired by confocal microscopy.

SPLINE AND IDEAL: FROM REAL TO VIRTUAL SCULPTURES, AND BACK

We present an original approach of virtual sculpting incarnated in a unified space-time interactive modeler named Splimo (for Spline Modeler), which is specifically designed for the creation of tubular spline works. Oriented towards artistic creation, it allows the realization of virtual transcriptions of real art pieces, as well as the creation of animated virtual sculptures, presented in an exhibition mode. Drawing curves in the virtual world is a way to be free of the constraints of the real sculptures, that’s why we call it “ideal”. Splimo may however also be used as a virtual prototyping tool to experiment new shapes to be later designed in the real world.