Method of data acquisition for three-dimensional imaging
Described are embodiments of methods of obtaining three-dimensional (3D) surface data of an object scene such as an intra-oral cavity. For example, measured surfaces may include the enamel surface of teeth, the dentin substructure of teeth, gum tissue and various dental structures. The methods can also be applied in medical applications and other applications in which 3D measurement data are acquired with maneuverable 3D measurement devices. In certain embodiments, the measurement device is positioned and translated to enable 3D data to be acquired for a backbone 3D data set. Subsequent controlled motion of the measurement device enables additional 3D data to be acquired and accurately joined to the backbone 3D data set.
1. A method of obtaining three-dimensional (3D) surface data of an intra-oral cavity, the method comprising:
providing a 3D measurement device having a measurement field of view;
moving the 3D measurement device during a first scan segment within the intra-oral cavity so that the measurement field of view scans across a first surface of a dental arch while acquiring, by the 3D measurement device, 3D data for the first surface, the first surface being one of an occlusal surface, a buccal surface and a lingual surface of the dental arch, the 3D data for the first surface defining a backbone 3D data set for the dental arch;
moving the 3D measurement device after completion of the first scan segment to a position wherein the measurement field of view at least partially overlaps the first surface;
initiating acquisition of 3D data at the position at a beginning of a second scan segment;
moving the 3D measurement device during the second scan segment within the intra-oral cavity so that the measurement field of view scans across a second surface of the dental arch while acquiring, by the 3D measurement device, 3D data for the second surface, the second surface being a different one of the occlusal surface, the buccal surface and the lingual surface of the dental arch;
geometrically registering the 3D data for the second surface with the 3D data for the first surface during the acquisition of 3D data for the second surface to produce a first registration result; and
based on the first registration result, joining the 3D data for the second surface with the 3D data for the first surface during the acquisition of 3D data for the second surface.
2. A method according to claim 1 , further comprising:
moving the 3D measurement device within the intra-oral cavity so that the measurement field of view scans across a third surface of the dental arch while acquiring, by the 3D measurement device, 3D data for the third surface, the third surface at least partially overlapping the first surface and being a different one of the occlusal surface, buccal surface and lingual surface of the dental arch with respect to the first and second surfaces;
geometrically registering the 3D data for the third surface with the 3D data for the first surface during the acquisition of 3D data for the third surface to produce a second registration result; and
based on the second registration result, joining the 3D data for the third surface with the 3D data for the first surface during the acquisition of 3D data for the third surface.
3. A method according to claim 2 , wherein the first surface is the occlusal surface of the dental arch, the second surface is the buccal surface of the dental arch, and the third surface is the lingual surface of the dental arch.
4. A method according to claim 1 , wherein the first surface is the occlusal surface of the dental arch.
5. A method according to claim 4 , wherein the second surface is the buccal or the lingual surface of the dental arch.
6. A method according to claim 1 , wherein the 3D measurement device is an accordion fringe interferometer measurement device.