Photogrammetry
Photogrammetry is the process of using photographic captures to generate geometry, this is done by using optical computations to find similar and overlapping features and projective geometry to align these images to build up a 3D model. Occlusion and depth is estimated via aligning these images to try and position photographic data the 3D space.
Videogrammetry is the same however video content is used and each frame is separated to create the alignment data of these stills. Photogrammetry does suffer with calculating z depth with as much accuracy as Lidar scanning due how it may interpret scale and overlaps of the subject.
The key advantage of photogrammetry over some other forms of 3D scanning is in resolution as almost any camera can be used allowing for higher spec photographic data to be captured resulting in more photorealistic models as texture data is not lost.
While the invention of the method is attributed to Aimé Laussedat,[2] the term "photogrammetry" was coined by the Prussian architect Albrecht Meydenbauer,[3] which appeared in his 1867 article "Die Photometrographie."[4]
Photogrammetry of the headquarters of Fazenda do Pinhal, São Carlos-SP, Brazil
There are many variants of photogrammetry. One example is the extraction of three-dimensional measurements from two-dimensional data (i.e. images); for example, the distance between two points that lie on a plane parallel to the photographic image planecan be determined by measuring their distance on the image, if the scale of the image is known. Another is the extraction of accurate color ranges and values representing such quantities as albedo, specular reflection, metallicity, or ambient occlusion from photographs of materials for the purposes of physically based rendering.
Close-range photogrammetry refers to the collection of photography from a lesser distance than traditional aerial (or orbital) photogrammetry. Photogrammetric analysis may be applied to one photograph, or may use high-speed photography and remote sensing to detect, measure and record complex 2D and 3D motion fields by feeding measurements and imagery analysis into computational models in an attempt to successively estimate, with increasing accuracy, the actual, 3D relative motions.
From its beginning with the stereoplotters used to plot contour lines on topographic maps, it now has a very wide range of uses such as sonar, radar, and lidar.