4.3.1.4 Firmware Operating System 5,' 
Another important aspect of the system configuration lies in the 
turnkey operation provided by the firmware (read only memory) 
operating System. A number of high level language graphics and 
image manipulation instructions burnt into the firmware. This allows 
the user to interact with the system and initiate a number of command 
operations for memory management, presentation, pipeline proce- 
ssor, and overlay graphics. 
4.3.1.5 System Computer and Co-Processor 
As shown in the figure, the system is controlled by a small 
system computer through which firmware commands are initiated 
thereby allowing user interaction via keyboard, trackball, and data 
table entry. Also the system can be interfaced with an external 
co-processor for carrying out complex and sophisticated processing 5. 
such as FFT, geometric corrections, etc. 
5.0 DESIGN AND DEVELOPMENT OF VIDEO-RATE IMAGE PROCE- 
SSING SYSTEMS AT SPACE APPIICATIONS CENTRE (ISRO) 
A number of image processing systems have been developed 
or are under development at Space Applications Centre (ISRO) and 
these are described below: 
n^ 
5.1 Digital Density Slicer with Colour Encoding and Area Measurement 9. 
Density Slicer and its measurement is a very useful concept 
which provides qualitative and quantitative information about trans- 
mittance characteristics of an object which in turn provides 
information about features in images taken through different types 
of sensors used in earth resources and weather satellites. 
  
The system consists of a light box, TV camera and lens, a 
console with processing electronics, and a display monitor. The 
system has several sub-units such as shading corrector, log- 
video amplifier, digital TV Sync generator, a digital video frame 
memory, and a micro-processor unit. 
5.1.1 Design Features 
a. It can accept input from 5.3 
(i) computer compatible tape (CCT) 
(ii) Film transparencies through a video camera, and 
(iii) Video tape recorder. 
b. It is a real time and interactive system. It provides display 
of reference colours, input video, stored image, and sliced 
image in 16 colours. 
c. It has facility for separately looking at sliced image and overlay 
characters. 
d. It provides area and density computations and measurement. 
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