Patent ID: 11967023
Assignee: COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 14:
15. A system for use in colourising a three-dimensional (3D) point cloud of an environment, the system including one or more electronic processing devices configured to:
a) use geometric data captured by a mapping device to:
i. determine a 3D point cloud of the environment; and,
ii. determine a mapping device trajectory;

b) obtain video data indicative of a video recording of the environment captured by a camera moving along a camera trajectory, the video data including a plurality of frames;
c) determine camera extrinsic parameters indicative of a transformation which transforms 3D points in a mapping device coordinate system to a camera coordinate system;
d) for each of a plurality of frames, the one or more electronic processing devices are configured to:
i. determine timing information indicative of a time of capture of the frame;
ii. determine a position of the camera along the camera trajectory using the mapping device trajectory, the timing information and the camera extrinsic parameters;
iii. identify at least some 3D points of the point cloud in the frame based at least in part on the position of the camera and determining a local point cloud that captures a scene in the immediate vicinity of the camera, wherein a visibility check is performed on the local point cloud to determine points in the local point cloud that are visible from the perspective of the camera for a given frame; and,
iv. determine a candidate colour for the at least some of the 3D points using a colour of a corresponding pixel in the frame extracted from the video data; and,

e) assign a colour to one or more points of the 3D point cloud using candidate colours obtained from multiple frames, wherein assigning the colour includes determining an angle between the viewpoint to a surface where each 3D point is located on, and assigning a colour using a colour corresponding to the 3D point where the angle is closest to 90 degrees.