5. Conclusions
We presented a novel N-frame graph matching algorithm to handle partial matching for 3D reconstruction. The algorithm is effective for aligning data sets with relatively small overlap and is robust in handling noisy data obtained by low-cost scanner scanners such as Kinect and PrimeSense. We also develop an iRobot SLAM system to navigate and reconstruct a 3D indoor environment. The proposed N-frame graph matching model first extracts a set of N-corresponding tuples. Then the mutual spatial consistency of these features (among multiple frames), together with their descriptor similarity, is used to find an optimal correspondence among these features. Feature correspondences are then used to align and stitch frames together. Experiments show that our algorithm has better reliability than existing algorithms in the reconstruction of noisy and low-frame-rate 3D scans. Despite better accuracy and robustness, a limitation of multiframe matching is efficiency, especially when simultaneously matching many frames. Now that in 3D reconstruction, frames only differ by rigid transformations, the correct rate of the correspondence is more important than the number of corresponding pairs that are identified. Hence, increasing the similarity threshold of descriptors will suppress the size of initial correspondence set, and will greatly reduce the dimension of the affinity matrix. We also plan to explore better optimization strategies [50] and parallel implementation to improve the speed of matching computation.