Patent ID: 11887271
Assignee: HONG KONG APPLIED SCIENCE AND TECHNOLOGY RESEARCH INSTITUTE CO., LTD
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 5:
6. The method of claim 4, wherein identifying the plurality of matching line-pair groups further comprises:
transforming the first discriminative line-pair to the reference coordinate by applying the first transformation matrix to each point on the first discriminative line-pair, such that the first line of the first discriminative line-pair is aligned with X-axis of the reference coordinate;
projecting the second line of the first discriminative line-pair onto Y-Z plane of the reference coordinate to obtain a first projected line;
obtaining a first acute angle between the first projected line and Y-axis of the reference coordinate;
transforming the second discriminative line-pair to the reference coordinate by applying the second transform matrix to each point on the second discriminative line-pair, such that the first line of the second discriminative line-pair is aligned with the X-axis of the reference coordinate;
projecting a second line of the second discriminative line-pair on the Y-Z plane to obtain a second projected line;
obtaining a second acute angle between the second projected line and Y-axis of the reference coordinate;
calculating an absolute difference between the first acute angle and the second acute angle as a compass angle difference; and
determining that the first discriminative line-pair and the second discriminative line-pair form the matching line-pair group if the compass angle absolute difference is less than a threshold of a compass error of the scanning device.