Method for calibrating at least one camera of a 3d scanner and 3d scanning system implementing said method

A method for performing a calibration procedure while or after performing a three-dimensional (3D) scanning procedure with a three-dimensional (3D) scanner, the three-dimensional (3D) scanner having a set of cameras and at least one processor in communication with the set of cameras, the set of cameras comprising at least a first camera and a second camera, the method comprising:

• a. a. capturing, with the set of cameras, a plurality of spatially neighboring frames of a surface of a target object being scanned to generate 3D measurements of the surface of the target object, wherein the target object has a scale artifact fixedly associated with the target object to improve accuracy of the 3D measurements of the surface and wherein a set of images of the plurality of spatially neighboring frames includes data conveying a representation of at least a portion of the scale artifact and at least a portion of the surface of the target object;
• b. b. processing, with the at least one processor, the set of images conveying the representation of at least the portion of the scale artifact and at least the portion of the surface of the target object to both:
• i. generate the 3D measurements of the surface of the target object by processing the representation of at least the portion of the surface of the target object in the set of images;
• and
• ii. perform a calibration procedure comprising:
• A. deriving at least one derivable camera parameter of the set of cameras by processing dimension information corresponding to the scale artifact and the representation of at least the portion of the scale artifact in the set of images;
• and
• B. calibrating, with the at least one processor, at least some of the 3D measurements of the surface of the target object at least in part using the at least one derivable camera parameter.

A three-dimensional (3D) scanner comprising:

• a. a set of cameras comprising a first camera and a second camera, the set of cameras configured to capture a plurality of spatially neighboring frames of a surface of a target object being scanned to generate 3D measurements of the surface of the target object, wherein the target object has a scale artifact fixedly associated with the target object to improve accuracy of the 3D measurements of the surface and wherein a set of images of the plurality of spatially neighboring frames includes data conveying a representation of at least a portion of the scale artifact and at least a portion of the surface of the target object;
• and
• b. at least one processor in communication with the set of cameras, the at least one processor configured to:
• i. process the set of images to both:
• A. generate the 3D measurements of the surface of the target object by processing the representation of at least the portion of the surface of the target object in the set of images;
• and
• B. perform a calibration procedure while or after capturing the plurality of spatially neighboring frames of the surface of the target object calibration, the calibration procedure comprising:
• C. deriving at least one derivable camera parameter of the set of cameras by processing dimension information corresponding to the scale artifact and the representation of at least the portion of the scale artifact in the set of images;
• and
• calibrating, with the at least one processor, at least some of the 3D measurements of the surface of the target object at least in part using the at least one derivable camera parameter.