Using multispectral informations for 3D reconstruction

We describe in this paper a stereoscopic system based on a multispectral camera and a projector. To be used, this system must be calibrated. This starts by a geometrical calibration of the stereoscopic set using a weak calibration. It is also necessary to know the spectral response of each element in the acquisition chain, from the projector to the camera. Then, image acquisition can begin. To acquire a multi-spectral image, we have just to use the projector to send a luminous pattern on the scene. The projection of the pattern in the image is detected and labeled since the projector was characterized during the calibration step. Finally, we can obtain the 3D position of the different parts of the luminous pattern on the scene by using triangulation. Moreover, a spectral reflectance can be associated to each of them. The colorimetric accuracy obtained by a multispectral camera is totally improved compared with a color camera.