brightness details and to compute the selected values of mathe 
matical expectation (ME), mean square deviation (MSD), spatial- 
frequency spectrum and density and function of distribution of 
these parameters for given objects or areas of terrain. 
The rough schematic diagram of basic processes for solving 
these problems is given in Pig. 2. 
Conversion 
Préparaitor 
of photo 
of initial 
image into 
data and 
digital form 
*»■ 
entering 
them in 
computer 
Calculation 
Statistical 
of bright- 
processing 
ness cha- 
of results 
racteris- 
of determi- 
tics of 
nation of 
terrain 
brightsness 
elements 
characteris- 
tics 
Pig. 2. Rough block diagram for determining and 
statistical processing of terrain brightness 
characteristics. 
Conversion of the original negative (section of negative) 
and sensitogram into digital form is perfomed with the aid of 
the image input/output device (HOD) of, for instance, the 
type "Colormation S-4500”. As a result, the matrix of values 
of optical density and image elements, each measuring a x a 
(usually 12.5 x 12.5, 25 x25, 50 x 50, 100 x 100 or 200 x 
200 nm) is recorded on the magnetic tape. 
For conversion of the initial matrix of the values of 
optical density of the image into the matrices of original 
brightness characteristics of terrain elements the necessary 
initial data are entered into the computer. 
1. Coordinates of reference points in the coordinate 
systems of the digital image, picture and terrain required 
for establishing relationships between these coordinate systems. 
The coordinates of centers of sensitogram fields in the 
HOD system used in computing the mathematical expectations 
of the values of optical density of sensitogram fields.