A flexible method for multi-view point clouds alignment of small-size object

Alignment is a key step of the point cloud processing. We propose a flexible, easy-implemented, low-cost alignment method for multi-view point clouds of small-size objects (<= 50 cm). The method is based on the idea of rotating measurement, firstly more than three pieces of point clouds of cylinder calibration pattern are used for calibrating the center axis of a single-axis turntable in the scanner's coordinate system, so the rigid relationship of the turntable and scanner can be obtained. Then the rotation matrix can be calculated using the known angle parameter of the turntable, and finally an arbitrary view of point cloud can be easily transformed into a unified coordinate system by the rotation transformation. Our method does not require overlapping feature or co-markers constraint between point clouds, and only the rigid relationship between the scanner and the turntable and rotate angle need to be known. More importantly, the calibration of the turntable is flexible and low-cost: (1) the calibration pattern can be a common cylinder objects (such as cup, paper tube, caddy, water pipe, etc.), (2) the turntable and the alignment method can be integrated with variety 3-D scanners. The result of experiment has demonstrated the efficiency and automatic characteristic of the alignment method compared with other two convention methods. (C) 2014 Elsevier Ltd. All rights reserved.