[IMAGE] SURVEY j [EDIT] e j emn [HELP] 
dd [ À - 
{Draw histogram miRelative orientation: Data file Input to EM3DPSjj|On screen Perspective map 
| Look grey value H Absolute orientation Graphic Compress data  ||On plotter Color perspective map 
[Contrast enhancement|||Survey DSM e EM3DPS to CAD On printer Contour line 
Clay enhancement} Auto generate DSM [|= t = p Stereo contour line 
| Edge enhancement|| Survey contour Zoom Hn Edit Draw [Perspective map] Plane map 
[mage sharping Survey length Copy Zoom Line Contour line Images superimposition 
{Image smoothing Survey angle Delete [Copy Circlel{{plane map Image & graphics overlay| 
| Image segment Survey area (2D) Move Delete | Box | — Perspective image 
[Compare two images |||Survey plane map Rotate Insert | Fill ||Data tables 
‚High resolution | Survey volume Annotation|||Move Poly Perspective map 
FE | Sur vay area (3D) Emm Rotate | Text Contour line 
— -—— plane map 
Image (16 level) 
Fig.3 The Diagram of The System Software 
  
  
Linear strech 
Non linear strech 
Histogran equalization 
Histogram specification | 
  
  
  
rd 
m 
[a 
LE E 
Al 
x 
0090408080 —120 160 300 240 Db edendi candi di ie itd 
Histoneram for enhanced imeem 
  
Fig.4 Screen menu display in the case of 
contrast enhancement 
01 and0 2 are not equal, it is difficult to observe 
stereomodel directly. There are two ways to solve 
this problem: 
® the left and right optical system of the 
mirror stereoscope have the ability to rotate images. 
© After the relative orientation, the left and 
the right digital images are rotated according to the 
two angles (04 and 02) calculated by the relative 
orientation. 
In order to make the optical system of the mirror 
stereoscope as simple as possible, EM3DPS uses 
the second method. 
4. THE SOFTWARE OF THE SYSTEM 
4.1 AN OVERVIEW OF THE SOFTWARE 
All of the programs in the system are written in C 
and assembles languages, So the hardware potentials 
of the microcomputer have been used fully.So far, 
there are six main functions in the system. They are: 
e Basic digital image processing functions (IM 
AGE) ; 
  
  
Fig.5 The screen dislpay of a stereopair 
Orientations, 3D and 2D surveying (SURV 
EY); 
Data, graphic, and image editing (EDIT); 
Data file format transformation (TRANSF 
ORM); 
Result data output (OUTPUT); 
e On-line help system (HELP); 
There are several sub-functions in each main 
function. All the functions in the system are 
orgnized in menu, thus making it quite easy to learn 
or operate the system. Fig.3 is the diagram of the 
system software functions and Fig.4 is the screen 
menu display in the case of image contrast 
enhancement. 
4.2 CHARACTERISTICS AND OPERATIONAL 
ASPECTS 
4.2.1 Basic Digital Image Processing. In order to 
improve the quality of the digital images which will 
be used in 3D or 2D surveying and analysing, the 
system provides some basic digital image processing 
functions. in addition to improving the image