Definition of digital photogrammetry

English: the basic concepts of digital photography

There are two main views on the definition of digital photogrammetry in the world.

A. Digital photogrammetry is a branch of photogrammetry. Based on the basic principles of digital image and photogrammetry, it applies the theories and methods of computer technology, digital image processing, image matching and pattern recognition to extract the geometric and physical information of the subject in digital form.

The United States and other countries call it soft copy photogrammetry, and Professor Wang calls it full digital photogrammetry. This definition holds that in the process of digital photogrammetry, not only the product is digital, but also the original data of intermediate data recording and processing are digital.

B Another definition only emphasizes that the intermediate data record and the final product are in digital form, that is, digital photogrammetry is a branch of photogrammetry based on the basic principle of photogrammetry, which uses computer technology to extract the geometric and physical information expressed by the subject in digital form from images (including hard copy, digital images or digitized images).

The definition of digital photogrammetry includes computer-aided mapping (usually called digital mapping) and digital image mapping.

Digital image mapping is to process digital images or digitized images with computers, and replace the stereoscopic measurement and recognition of human eyes with computer vision (the core of which is image matching and image recognition), so as to complete the automatic extraction of geometric and physical information of images.

Another type is called hybrid digital photogrammetry. Usually, a pair of CCD digital cameras are installed on the analytical mapper to digitize the local image to be measured and obtain the coordinates of the points through digital correlation (matching).