Method of 3d panoramic mosaicing of a scene

Abstract

A method of 3D mosaicing of a scene as a 3D mosaic, wherein at least one 3D reconstruction having been obtained without a priori information about the scene, in the course of the following steps of: acquisition of successive images by a panoramic sensor moving along an unconstrained 3D reconstruction trajectory, such that the image of at least one point of the scene is in at least 3 successive 2D panoramic images obtained according to various panoramic system-point of the scene directions, rectification of these images on different rectification planes covering different directions, and matching of the rectified images, 3D reconstruction on reconstruction planes on the basis of the rectified matched images, the last 2D panoramic acquired image being called current 2D panoramic image, it further comprises the following steps: A) On the basis of the obtained 3D reconstruction and of the current 2D panoramic image, choosing one or more projection surfaces on which the mosaic will be constructed, B) Selecting sectors of the current 2D panoramic image, and selecting textures in the selected sectors by selecting visible parts that is to say that are not hidden by a surface of the scene, with the aid of the 3D reconstruction, C) Projecting the selected textures onto each projection surface and fusing the textures in each projection surface so as to thus obtain a conformal mosaic on each projection surface.

1 . A method of 3D mosaicing of a scene as a 3D mosaic, wherein at least one 3D reconstruction having been obtained without a priori information about the scene, in the course of the following steps of:
 acquisition of successive images by a panoramic sensor moving along an unconstrained 3D reconstruction trajectory, such that the image of at least one point of the scene is in at least 3 successive 2D panoramic images obtained according to various panoramic system-point of the scene directions,   rectification of these images on different rectification planes covering different directions, and matching of the rectified images,   3D reconstruction on reconstruction planes on the basis of the rectified matched images,   the last 2D panoramic acquired image being called current 2D panoramic image,   it further comprises the following steps:
 A) On the basis of the obtained 3D reconstruction and of the current 2D panoramic image, choosing one or more projection surfaces on which the mosaic will be constructed, 
 B) Selecting sectors of the current 2D panoramic image, and selecting textures in the selected sectors by selecting visible parts that is to say that are not hidden by a surface of the scene, with the aid of the 3D reconstruction, 
 C) Projecting the selected textures onto each projection surface and fusing the textures in each projection surface so as to thus obtain a conformal mosaic on each projection surface. 
   
     
     
         2 . The method of 3D mosaicing of a scene as claimed in  claim 1 , wherein step B comprises a step of selecting sectors of the 2D current panoramic image which correspond to the chosen projection surfaces. 
     
     
         3 . The method of 3D mosaicing of a scene as claimed in  claim 1 , wherein the steps A to C are repeated at each new panoramic image acquisition. 
     
     
         4 . The method of 3D mosaicing of a scene as claimed in  claim 1 , wherein the choice of the projection surfaces is made in all the directions which are compatible with the reconstruction planes of the 3D reconstruction. 
     
     
         5 . The method of 3D mosaicing of a scene as claimed in  claim 1 , wherein each texture exhibiting a resolution, it comprises a step for determining the resolution of the textures and in that the fusion of the textures of step C) is carried out as a function of these resolutions. 
     
     
         6 . The method of 3D mosaicing of a scene as claimed in  claim 1 , wherein the textures are directly projected on the projection surfaces, without passing through an intermediate step of projection in a focal plane. 
     
     
         7 . The method of 3D mosaicing of a scene as claimed in  claim 1 , wherein the rectification planes are chosen in directions such as the rectification planes cover the current 2D panoramic image. 
     
     
         8 . The method of 3D mosaicing of a scene as claimed in  claim 1 , wherein the 3D reconstruction is obtained on the basis of 2D panoramic images acquired before the current 2D panoramic image, and acquired on said trajectory. 
     
     
         9 . An apparatus for 3D mosaicing of a scene, which comprises a panoramic system able to form images of the scene, and to move along a trajectory, furnished with relative image to image location means and, linked to this panoramic system, a computer comprising means for implementing the 3D mosaicing method as claimed in  claim 1 .