Surface Scanner

Surface scanners are very analogous to cameras. Like cameras, they have a cone-like field of view, and like cameras, they can only collect information about surfaces that are not obscured. While a camera collects color information about surfaces within its field of view, surface scanners collect distance information about surfaces within its field of view. The “picture” produced by a surface scanner describes the distance to a surface at each point in the picture. If a spherical coordinate system is defined in which the scanner is the origin and the vector out from the front of the scanner is φ=0 and θ=0, then each point in the picture is associated with a φ and θ. Together with distance, which corresponds to the r component, these spherical coordinates fully describe the three dimensional position of each point in the picture, in a local coordinate system relative to the scanner.

For most situations, a single scan will not produce a complete model of the subject. Multiple scans from many different directions are usually required to obtain information about all sides of the subject. These scans have to be brought in a common reference system, a process that is usually called alignment or registration, and then merged to create a complete model.

For facial analysis usally two scanners are aligned in a triangle-constelation with the scan-subject at one corner, and the cameras at the other two corners. With this setup usally one scan is sufficient for a full facial analysis.

micro-CT

More information can be found at the official website www.micro-ct.at