AST Digital Magazine July 2017 Digital-July | Page 24

Volume 14
The purpose of the mesh face-mask is to simu-
late some of the issues associated with H.264
and H.265 image compression.
It is not a perfect analogy, but the mask does
a respectable job of damaging fine details and
mucking up clean lines between colors.
Have your clients wear both the sunglasses and
the face-mask at the same time while performing
the exercise.
They may look like a Martian, but they will be
gaining valuable information... like NASA astro-
nauts training for a mission.
If they choose not to wear the sunglasses and
mesh face-mask, make sure they know the ob-
served detail and clarity for each measured PPF
will be better than what security cameras can de-
liver.
When they are not wearing the sunglasses and
face-mask, the results will be more a recording
made with a high-end camcorder or DSLR cam-
era.
Security cameras have to make compromises to
keep their prices down and to efficiently utilize
hard-drive space.
High-end camcorders and DSLRs do not have to
make such compromises.
Laser Range-Finder?
Many hunters, golfers and outdoor enthusiasts
already own a laser range-finder. They certainly
make measuring distances fast and easy.
This is the laser range-finder I use. If you do not
have access to one of these, additional measur-
ing options are discussed below.
July 2017 Edition
Why the cheetah?
One of the props I use is a lifelike cheetah. I
chose it because as the resolution becomes
less and less, the cheetah starts to look more
and more like a dog.
This seems to help some people recognize the
significant contribution of image detail during an
incident investigation.
If they aren’t capturing enough detail to recog-
nize one species from another, how are they
ever going to distinguish one human from an-
other?
Stop Reading... You are done, go try
it!!
For you over-achievers, here is additional infor-
mation you may find useful...
The HEED Index has nothing to do with FoV
The HEED Index has nothing to do with a cam-
era’s field-of-view (FoV). It is useful for under-
standing the amount of detail a person can see
compared to the visual acuity terms describing
it.
In other words, the HEED Index is a point-to-
point tool useful in describing the amount of
detail you can expect from a properly installed,
high-quality surveillance camera.
It is not useful for describing the coverage area
(square footage or field-of-view) of a particular
camera.
Increasing camera resolution changes defini-
tion?
Please note that the distance from the object
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