256
CONSEQUENCES OF THE PHOTOGRAMMETRICAL VIEW OF SOLVING SPECIAL
TASKS IN DIGITAL PHOTOGRAMMETRY WITH SERIAL COMPUTERS
DR. ERHARD PROSS
Research Centr of Geodesy and Cartography
Karl-Rothe-Str. 10 - 14, Leipzig, DDR-7022, G. D. R.
1. Development of image structures
Photogrammetric methods use information in the form of two-dimensional
representations of facts. In connection with map production and generation
of topographic and other thematic information, respectively, part of the
Earth's surface is imaged at the same time.
While during the last years mainly photographic images - i. e. analogue
representations - had been used, recently digital representations in the
form of so-called digital images gained in importance. This process was
influenced by the increased employment of digital computers as well as
digital image processing.
Figure 1 shows the methodical development from analogue over differential
and analytical to digital. This reflects - as typical in photogrammetry -
in respective technical devices.
From the point of view of discretization of data, firstly the plane co-ordi
nates are discretized (differential - one, analytical - two), but then the
grey value range too (digital - three). The last transition corresponds to
a qualitative jump, because the traditional analysis is not sufficient for
the mathematical model, but functional analytical methods have to be applied
(see also /1/). This means inter alia, that data and processes basically
have to be remodelled in an uniform calculation, whereby analogue, differen
tial and analytical methods are naturally imbedding (/1/).
