Automatic global non-rigid scan point registration

A system for scan point registration, the system comprising:

• a coarse registration circuit configured to generate a model transformation based on a coarse registration between an object captured in a digital point scan and a digital object model;
• an alignment metric circuit configured to calculate an alignment metric based on a distance measurement between the object of the digital point scan and a transformed digital object model, the transformed digital object model generated by application of the model transformation to the digital object model;
• a fine registration circuit configured to perform a fine registration between the transformed digital object model and the object of the digital point scan, in response to the alignment metric exceeding a selected threshold value;
• a random rotation circuit configured to apply a random rotation to the digital object model to generate a rotated digital object model, in response to the alignment metric not exceeding the selected threshold value;
• and
• a translation circuit configured to translate the rotated digital object model towards a centroid of the object of the digital point scan, the translated digital object model for use by the coarse registration circuit in a scan point registration iteration.

At least one non-transitory computer readable storage medium having instructions encoded thereon that, when executed by one or more processors, result in the following operations for scan point registration, the operations comprising:

• generating a model transformation based on a coarse registration between an object captured in a digital point scan and a digital object model;
• calculating an alignment metric based on a distance measurement between the object of the digital point scan and a transformed digital object model, the transformed digital object model generated by application of the model transformation to the digital object model;
• in response to the alignment metric exceeding a selected threshold value, performing a fine registration between the transformed digital object model and the object of the digital point scan;
• and
• in response to the alignment metric not exceeding the selected threshold value, performing:
• a random rotation of the digital object model,
• a translation of the rotated digital object model towards a centroid of the object of the digital point scan, and
• an iteration of the method for scan point registration, using the translated digital object model.