Photogrammetry is a non-contact scanning technology that utilizes photographs to make scientific measurements and create digital
modeling in 3D. With photogrammetry, It is possible to determine the distance between two points in a photograph if the scale of the image is given.
Photogrammetry uses optics, the study and behavior of light, combined with projective geometry to determine points on an object. The distance between these points are then estimated and a
3D digitized model is created.
Stereophotogrammetry is slightly more complex than photogrammetry and utilizes two photographs taken from different angles to estimate intersecting coordinates. With these estimates known, it is possible to create a
3D measurement of an object with the two photos.
For the most accurate results, photogrammetric data is combined with range data from
3D laser scanners or white-light digitizers. This is because photogrammetry is extremely accurate measuring the X and Y axis' of a coordinate plane, while
3D laser scanners and white-light scanners are more accurate in the Z axis range.
There are many different trades and professions that utilize photogrammetry and stereogrammetry. In engineering and architecture, the image of a building or metal part can be analyzed and
CAD designs can be created easily. The entertainment business can utilize
photogrammetry by merging real world objects with CGI. With stereophotogrammetry, surface maps can be created with just a few photographs.
