the 
ind 
jen 
(4) 
‚in 
oy 
allel 
the 
Y's 
left 
(5) 
ates 
Xp 
the 
the 
the 
fter 
(6) 
02 
    
  
  
  
       
     
  
     
  
Image 
Acquisition 
interface 
board 
Electron 
microscope 
  
  
Image 
scanner 
  
CCD camera Hard and floppy disk Printer 
= © Ma 
Microcomputer 
  
  
  
  
Color Plotter 
monitor 
A 
| er 
i 
  
  
  
  
  
  
  
  
  
mirror 
stereoscope 
d 
  
  
Fig.2 Diagram of System Hardware Configuration 
2.3 ABSOLUTE ORIENTATION EQUATIONS 
Although EM imaging system is regarded as parallel 
projection, the absolute orientation equations for EM 
images are the same as these in conventional 
photogrammetry. Absolute orientation can also be 
done by means of microcosmic control points. 
3 SYSTEM HARDWARE 
CONFIGURATION 
The EM3DPS is functionally composed of four major 
components: digital image input instruments,a 
microcomputer, data output devices and a mirror 
stereoscope. Fig.2 is the diagram of system 
hardware configuration. 
3.1 DIGITAL IMAGE INPUT INSTRUMENTS 
Three types of image input instruments are used in 
the system. They are: an image scanner, a CCD 
solid camera and an electron microscope which is 
directly connected with a computer through an 
image acquisition interface board. Usually, these image 
input devices needn't be connected with the 
microcomputer installed EM3DPS.If only the format 
of the image data file of the input instruments is 
known, we can get the digital image from the floppy 
disk. Compared with the provious two types of 
image input instruments, the third has most 
potentials. A real-time electron microscope 3D 
processing system may be developed on this kind of 
hardware system. 
3.2 MICROCOMPUTER 
In order to realize various digital image processing 
functions and 3D data acquisition efficiently, the 
following microcomputer hardware components are 
required: 
e IBM PC/AT, 80286, 80386 or its compatibles 
with at least 640KB memory; 
® A 40MB hard disk driver and a 1.2 MB or 
1.44 MB high-density floppy disk driver; 
® A math coprocessor compatible with the CPU 
(80287 or 80387 ); 
À standard VGA or TVGA; 
A high resolution color monitor; 
2MB or more expend or extend memory; 
An image acquisition board corresponding to 
a digital image input instrument. 
3.3 DATA OUTPUT DEVICES 
There are three types of data output devices in the 
system. They are: 
€ A printer. Various 2D or 3D data in table 
format can be output by means of the 
printer. Certainly, the printer can also be used to 
output graphics or black and white images in limited 
grey level. A HP LaserJet III printer has been used 
in the system. 
® A plotter. The plotter is mainly used to 
output various graphic information such as contour 
line, perspective map and plane map,etc. A Roland 
DPX-3500 plotter has been used in the system. 
€ A high resolution color monitor. The monitor is 
not only the main output device in the system but 
also an observing device in image processing and 
stereomodel surveying. Various data, graphics and 
images can be output on the monitor. 
3.4 MIRROR STEREOSCOPE 
The system chooses split-screen imagery for 
stereomodel display, so a mirror stereoscope is 
required. Because in general situation, the y axis of 
the screen coordinate system of the left and the 
right digital images are not parallel to the tilt axis of 
the specimen stage(refer to 2.2)and the two angles