Abstract : In this paper, we present an approach to integrate a pre-processing step of the Regions Of Interest (ROI) localisation into 3D scanners (laser or stereoscopic). The definite objective is to make the 3D scanner intelligent enough to localize rapidly in the scene, during the pre-processing phase, the regions with high surface curvature, so that precise scan will be done only in these regions instead of in the whole scene. In this way, the scanning time can be largely reduced, and that the results contain only pertinent data. To test its feasibility and efficiency, we simulated the pre-processing process under an active stereoscopic system composed of two cameras and a video projector. The ROI localisation is done in an iterative way. At first, the video projector projects a regular point pattern in the scene, and then the pattern is modified iteratively according to the local surface curvature of each reconstructed 3D point. Finally, the last pattern is used to determine the ROI. Our experiments showed that with this approach, the system is capable to localise all types of object, including small objects with small depth.