Hong Kong Applied Science and Technology Research Institute Company, Limited

Suk Ling Li

Xueyan Tang

Chun Li

Chongshan Liu

Computer implemented methods and computerized apparatus are provided for global registration between a first point cloud and a second point cloud obtained by a scanning device on an identical spatial scene at two separate instances. The method comprises extracting a first set of discriminative line-pairs from the first point cloud and a second set of discriminative line-pairs from the second point cloud, wherein a discriminative line-pair is a line-pair having high discriminative power compared to a randomly selected line-pair. In some embodiments, then a plurality of matching line-pair groups between the two sets of discriminative line-pairs are identified in accordance with one thresholding criterion related to between-line relationship, line geometry and line location; and a compass angle criterion related to compass errors of the scanning device. The method further comprises finding most reliable correspondence between the two point clouds by voting and then computing a global transformation matrix. Finally, the global transformation matrix is used to align the two point clouds. Embodiments of the present invention provide an accurate and efficient registration especially for building construction applications.

Method and system for global registration between 3D scans

Computer implemented methods and computerized apparatus for identifying planes of a 3D object in a 3D scene are provided. The method comprises receiving a point cloud and performs plane segmentation. In one embodiment, the point cloud is voxelized into a plurality of voxels of equal dimensions and the plurality of voxels are classified into three categories, wherein each first category voxel satisfies a planar requirement and a first neighborhood constraint, each second category voxel satisfies the planar requirement and a second neighborhood constraint, and each third category voxel does not satisfy the planar requirement. The method further comprises generating at least one reference plane from the first category voxels by first identifying a first category anchor voxel and recruiting its neighboring first category voxels to this at least one reference plane; and growing the at least one reference plane by absorbing second category voxels connecting to the at least one reference plane if they satisfy a voxel merging requirement and absorbing points in the third category voxels connecting to the at least one reference plane if they satisfy a point merging requirement. Then the set of at least one reference plane is used to represent the 3D object for further applications.

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Hong Kong, China

Suk Ling Li