What is Photogrammetry

The use of photography in surveying and mapping to ascertain measurements between objects.

The use of photography in surveying and mapping to ascertain measurements between objects.

The science of making reliable measurements by the use of aerial photographs to produce maps and precise three-dimensional positions of points. Photogrammetry is an engineering discipline and as such heavily influenced by developments in computer science and electronics.

Reverse process of perspective, which allows deriving actual measurements from a central projection thanks to the rules of projective geometry. The simplest form is flat, from single frame. The solid photogrammetry reconstructs the position of the points in space combining the same process on two or more frames differently oriented, in digital way. Before, the operator separately individuated each point.

It is an image-processing technique for generating the 3D model or obtaining geometric properties of a target object from many digital photos (taken from many angles). A variety of photogrammetry software (e.g. 3DF Zephyr ) have been provided, and some advanced smartphones or tablets with a 3D-scanning sensor make photogrammetry easier.

The process of transforming digital 2D photographs into a 3D mapping or a 3D model is defined as Photogammetry.

The science of taking measurements from photographs by computational models.

The science of making measurements from photographs/images, especially for extracting geometric information.

Photogrammetry is a surveying method through which precise rigorous information is obtained regarding the geometry, form, measurement, and material quality of the subject photographed. Given the identity relationship between photographic image and central projection, the operational processes allowing measurements to be obtained from the images, and therefore the metrical/geometrical contents of the objects to be investigated, are completely based on applying the principles of projection geometry to the photographic images. In general, describing the subject photographed requires establishing a spatial relationship among the object points, the points represented on the plate/film/sensor, their positions and inclinations with respect to the centres of projection and the optical axes of the photographic equipment. The combination of such operations, collectively called “orientations”, aims to identify, when known, the intrinsic (principal distance, position of the centre of projection with respect to the plate/sensor, lens distortion parameters, etc.) and extrinsic parameters (position and orientation of the photographic equipment with respect to the points of the subject) that characterise the photogrammetric model. The theoretical principles of photogrammetry refer to the equations of collinearity (with which the phtogrammetric system in the form of known and unknown variables can be analytically described) and epipolar geometry (with which it is possible to reduce the area in which one looks for relationships between homologous points).

The obtaining of reliable measurements from photographic images. Also, a scanning method comprising the projection of a pattern and photo capture in its 360° of an object to make a three-dimensional reconstruction.

The art of turning 2D images into 3D models, with the purpose of obtaining the metric and geometric characteristics from the objects.

The science of making measurements from photographs, especially for recovering the exact positions of surface points.

Technique permitting the set up of the coordinates of points (DEM) of an object surface by processing stereo images of the object surface.

A manual or digital technique used to analyse stereo photographs, to create 3D models, and to extract quantitative information.