Yves Tison

A 3D vision system for the measurement of the rate of spread and the height of fire fronts

This paper presents a three-dimensional (3D) vision-based instrumentation system for the measurement of the rate of spread and height of complex fire fronts. The proposed 3D imaging system is simple, does not require calibration, is easily deployable in indoor and outdoor environments and can handle complex fire fronts. New approaches for measuring the position, the rate of spread and the height of a fire front during its propagation are introduced. Experiments were conducted in indoor and outdoor conditions with fires of different scales. Linear and curvilinear fire front spreading were studied. The obtained results are promising and show the interesting performance of the proposed system in operational and complex fire scenarios.

Estimation of spreading fire geometrical characteristics using near infrared stereovision

In fire research and forest firefighting, there is a need of robust metrological systems able to estimate the geometrical characteristics of outdoor spreading fires. In recent years, we assist to an increased interest in wildfire research to develop non destructive techniques based on computer vision. This paper presents a new approach for the estimation of fire geometrical characteristics using near infrared stereovision. Spreading fire information like position, rate of spread, height and surface, are estimated from the computed 3D fire points. The proposed system permits to track fire spreading on a ground area of 5mx10m. Keywords: near infrared, stereovision, spreading fire, geometrical characteristics

Estimation of fire volume by stereovision

This paper presents a new approach for the estimation of fire front volume in indoor laboratory experiments. This work deals with fire spreading on inclinable tables. The method is based on the use of two synchronized stereovision systems positioned respectively in a back position and in a front position of the fire propagation direction. The two vision systems are used in order to extract complementary 3D fire points. The obtained data are projected in a same reference frame and used to build a global form of the fire front. An inter-systems calibration procedure is presented and permits the computation of the projection matrix in order to project all the data to a unique reference frame. From the obtained 3D fire points, a three dimensional surface rendering is performed and the fire volume is estimated.

Measurement of the geometric characteristics of a fire front by stereovision techniques on field experiments

This paper presents stereovision techniques for measurement of the geometrical properties (position, rate of spread, fire height, fire inclination angle, fire base width, view factor) of fires obtained by experimental burnings at field scale. The system consists of two synchronized and pre-calibrated multi-baseline stereo cameras operating in the visible spectrum. The cameras are positioned in the back and the lateral positions relatively to the direction of fire propagation. Algorithms have been developed in order to (i) register these cameras, (ii) model in three dimensions the fire front from the back stereoscopic images and (iii) estimate some geometrical properties of fire such as the inclination angle and the fire base width from the lateral stereoscopic images. A user graphical interface was developed as a practical tool to estimate fire propagation features and to display the obtained results. Fire spread experiments were conducted at field scale (about 20 m wide and 3 m high). The fuel consists of Mediterranean shrub vegetation. The obtained results are promising and show interesting performance achieved by the proposed system in operational and complex fire scenarios.

Dynamic fire modeling in Three-dimensional space

This work presents a new framework for three-dimensional reconstruction of dynamic fire fronts found in outdoor unstructured scenes. The proposed approach addresses the problem of segmenting fire front regions using color attributes and clustering techniques in order to extract salient points from stereo images. These points are then used to reconstruct their 3D position in the scene. A matching strategy is proposed to deal with mismatches due to occlusions and missing data. The proposed framework was successfully used to build 3D data part of dynamic fire fronts. This 3D information was used efficiently to estimate the approximate position of the fire front and its heading direction. The obtained results are promising and show the possibility of tracking dynamic objects with changing shapes like fire fronts in a three-dimensional space.

Measurement of laboratory fire spread experiments by stereovision

This paper presents a stereovision framework developed to monitor and to measure laboratory fire spreads. New algorithms were developed for the estimation of fire characteristics like position, rate of spread, height, depth and the distance between the fire front and metrological instruments.

Stereovision based algorithm for measuring fire spreading characteristics

This paper presents a new algorithm for automatically measuring fire spreading characteristics by means of a stereovision system. The proposed framework is based on the use of a pre-calibrated trinocular stereo camera. The first and second steps permit the segmentation and features detection in the images. The third step is a stereo matching approach used in order to automatically process successive images of spreading fires. In the fourth step, stereovision techniques are applied in order to derive the 3D fire structure. In the last step, new developed algorithms are used to estimate, in the case of complex fire spreading, information like the position of the fire over time, its rate of spread and its height.