ÐDetecting faces in images with complex backgrounds is a difficult task. Our approach, which obtains state of the art results, is based on a new neural network model: the Constrained Generative Model (CGM). Generative, since the goal of the learning process is to evaluate the probability that the model has generated the input data, and constrained since some counterexamples are used to increase the quality of the estimation performed by the model. To detect side view faces and to decrease the number of false alarms, a conditional mixture of networks is used. To decrease the computational time cost, a fast search algorithm is proposed. The level of performance reached, in terms of detection accuracy and processing time, allows to apply this detector to a real world application: the indexation of images and videos.

No abstract

No abstract

No abstract

Shared interface allowing several users in co-presence to interact simultaneously on digital data on a single display is an uprising challenge in Human Computer Interaction (HCI). Its development is motivated by the advent of large displays such as wall-screens and tabletops. It affords fluid and natural digital interaction without hindering human communication and collaboration. It enables mutual awareness, making participant conscious of each other activities. In this paper, we are interested in Mixed Presence Groupware (MPG), when two or more remote shared interfaces are connected for a distant collaborative session. Our contribution strives to answer to the question: Can the actual technology provide sufficient presence feeling of the remote site to enable efficient collaboration between two distant groups? We propose DigiTable, an experimental platform we hope lessen the gap between collocated and distant interaction. DigiTable is combining a multiuser tactile interactive tabletop, a video-communication system enabling eye-contact with real size distant user visualization and a spatialized sound system for speech transmission. A robust computer vision module for distant users' gesture visualization completes the platform. We discuss first experiments using DigiTable for a collaborative task (mosaic completion) in term of distant mutual awareness. Although Di-giTable does not provide the same presence feeling in distant and or collocated situation, a first and important finding emerges: distance does not hinder efficient collaboration anymore.