ves 
«1-7 
RS 
ol. 24 - II, 
ial 
ineiro, 
ian. 
o.l, pp. 
M2 
nic 
DIGITAL VIDEO STEREOSCOPY: REAL-TIME 
INSTRUMENTATION ISSUES 
R.R. REAL and Y. FUJIMOTO 
Photogrammetric Research Section, Division of Physics 
National Research Council of Canada, Ottawa, K1A OR6 
ABSTRACT 
Photogrammetric instrumentation is destined to become increasingly 
digital and video based because of its flexibility, cost effectiveness and, 
most importantly, for having the potential to extend photogrammetric 
practice into new domains, such as the control of dynamic processes. Fast 
digital image processing is relatively recent and implementation with fast, 
lower cost modular components is only just being realized. Hardware issues 
are discussed relating to stereo photogrammetric instrument design having 
the desired attributes based upon such components, with reference to 
development experience at NRC. 
1. INTRODUCTION 
The digitized image is initiating an unparalleled information revolution. 
Traditional chemical imaging systems will gradually yield to CCD imagers, 
parallel processors and disk storage. Reflect upon the fact that only 
thirty odd years ago there were vacuum tubes, black and white TV, carbon 
paper and many mechanical calculators; today we have camcorders, laser color 
printing systems, and mainframe computers on a chip. 
Fusing of imaging technology with electronics is fostering change in 
fields as disparate as agriculture and medicine, astronomy and manufac- 
turing, in ways that only hint at future potential. Photogrammetry should 
be front and center in the drive towards "precision 3-D intelligence", for 
the measurement and control of dynamic processes from TV input imagery; the 
essence of machine vision for computer integrated manufacturing. Electronic 
image acquisition and digital processing is also the essence of modern 
visual communication systems for visually enhancing or statistically 
evaluating some aspect of an image not readily apparent for the human eye. 
In general the system required for close-range, in-situ, filmless, real-time 
dynamic measurement and control, exemplified by machine vision in robotics, 
requires rapid image processing throughput based upon smaller format images. 
Issues relating to image acquisition hardware and processing components for 
this purpose are discussed elsewhere, El-Hakim 1986, Real, 1986. The visual 
communication application of image processing is somewhat complementary to 
the process control application. Large format, high fidelity images 
emulating photography are usually desired by the human viewer. Although one 
could speculate that no format is large enough, or resolution fine enough, 
for the discriminating viewer, the 1000x1000 pixel TV image appears to be a 
lower limit to having the psychological impact of being a "good" image, 
Seeley, 1978. So much so that from 1970 the Japan Broadcasting Corp. has 
been working on the development of a high definition television (HDTV) 
system to "unite the whole world into one television community," Fujio, 
1985. This paper discusses some of the issues of real-time acquisition, 
processing, display, and storage of TV images for image transfer systems in 
photogrammetry, with some experimental results appended. For a general 
85