1. A real-time method of 3D reconstruction of a scene, without a priori information about the scene, by means of 2D panoramic images of the scene, which comprises a step of processing these 2D panoramic images, characterized in that the 2D panoramic images arise from a panoramic sensor moving in displacement over an unconstrained 3D 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, and in that the step of processing these 2D successive panoramic images respectively obtained at successive instants comprises the following sub-steps: a) determining or updating, at each new acquisition, reconstruction planes of different directions in the scene to be reconstructed, b) determining, on the basis of pairs of panoramic images sliced up into sectors covering in totality each of the panoramic images, respectively formed of a 2D panoramic image obtained at an instant t and of another 2D panoramic image obtained at an instant t+Δt and for each chosen pair of images, rectification planes corresponding to the various chosen reconstruction planes, determining the various sectors in the two panoramic images corresponding to the various reconstruction planes, and projecting onto each of the rectification planes the corresponding sector of a 2D panoramic image of the pair, in a direct manner, that is to say by applying a mathematical transformation which causes each pixel of each sector of the panoramic image to pass directly into a corresponding pixel in the corresponding rectification plane without passing through an intermediate step of projection onto focal plane, so as to obtain a 2D rectified image, and projecting onto these same rectification plane and in a direct manner a sector of the other 2D panoramic image of the pair so as to obtain another 2D rectified image, c) matching, for each chosen rectification plane, the two 2D rectified images so as to obtain an intermediate 3D reconstruction in a 3D frame tied to the rectification plane, the so-called intermediate 3D frame, d) spatially fusing the intermediate 3D reconstructions, e) transforming each fused intermediate 3D reconstruction into a 3D frame including the reconstruction planes chosen in a), the so-called 3D reconstruction frame, so as to obtain a transformed intermediate 3D reconstruction, f) repeating steps b) to e) at least once on the basis of a new pair of 2D panoramic images and of at least one other rectification plane, so as to obtain at least one other transformed intermediate 3D reconstruction in this 3D reconstruction frame, g) temporally fusing, for each chosen construction plane, at least two transformed intermediate 3D reconstructions to obtain a 3D reconstruction of the scene, and h) steps b) to g) are carried out for each reconstruction plane chosen in step a), with the same panoramic images but with different sectors, so as to thus obtain as many 3D reconstructions as chosen reconstruction planes.