Plant point cloud acquisition, registration and optimization method based on TOF camera

A plant point cloud acquisition, registration, and optimization method based on a time of flight (TOF) camera, comprising:

• (1) placing a to-be-tested plant on a turntable, adjusting a view angle of the TOF camera, and aligning the TOF camera with the to-be-tested plant;
• (2) turning on the turntable so that it rotates automatically, and enabling the TOF camera to acquire point cloud data of the to-be-tested plant at intervals;
• (3) performing real-time preprocessing on each frame of point cloud data acquired by the TOF camera;
• (4) performing registration and optimization on every two adjacent frames of point cloud data, and then integrating the data to obtain complete plant point cloud data, comprising:
• (4-1) transforming a coordinate system of a second point cloud P2 to a coordinate system of a first point cloud P1 to obtain a point cloud P2′;
• (4-2) triangulating P1 and P2′, removing boundary points that do not form a triangular patch, but retaining points inside that do not form a triangular patch;
• (4-3) searching for a triangular patch of P2′ within the neighborhood of each triangular patch in P1, and checking whether the triangular patch in P1 intersects with or is in parallel to the triangular patches within the neighborhood;
• (4-4) according to the intersection and parallelism relationship, adjust a point cloud set of P2′ that is within the neighborhood of the triangular patch in P1 to obtain a point cloud P2″;
• (4-5) adding points in P2′ that do not form a triangular patch to P2″, and then performing downsampling to obtain a point set P2′deal;
• (4-6) transforming a coordinate system of an i-th point cloud Pi to the coordinate system of the first point cloud P1 to obtain a point cloud Pi′, and repeating steps (4-2) to (4-5) to obtain Pi′deal, wherein i≥3;
• and
• (4-7) integrating P1, P2′deal, and Pi′deal to obtain the complete plant point cloud data;
• and
• (5) using statistical filtering to remove the discrete noise in the plant point cloud data obtained in the registration and optimization process to obtain final point cloud data.