Abekas AirCleaner, Руководство пользователя

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56 AirCleaner • User Guide
4. Operations
Reaction Time
Reaction Time
Depending on the desired operation, AirCleaner requires one or two human operators.
To account for the fact that all humans have differing reaction times, AirCleaner
includes AutoClean
™
— a feature that eliminates the natural delayed reaction of
human operators to respond to an observed visual or aural event.
The AutoClean Feature
With AutoClean, four separate reaction times (one pair of audio/video reaction times
for each operator) can be programmed to automatically “back up” the trigger point of
the masking panic button. This gives each operator the time to recognize a violation
prior to the panic button press, so the masking will start before that point — and will
continue to be masked for the entire duration the given panic button is held down.
The four Reaction Time parameters drive the AutoClean function. Basically, these
parameters advance the starting trigger point of each panic button (in increments of
video frames). With respect to the video input to AirCleaner, the start of the trigger is
advanced to a point in time before the button was actually pressed.
AutoClean allows most violations to be masked entirely. For even more security, a
second screener can be added downstream from the first screener who will then have
a second chance to mask any portion of the violation missed by the first screener. This
second screener has a second set of audio and video Reaction Time parameters which
are tailored to their own reaction profile. During two-screener operation, AirCleaner
senses the total time both operators have held down their given Panic Buttons and
therefore masks out the entire violation.
Please note the Reaction Time parameters only affect the starting trigger point (when
the panic button is pressed), and does not affect the ending trigger point (when the
panic button is released). This helps to ensure the entire violation is masked, and
avoids back-timing into the end of the violation.
Determining Operator Reaction Time
It’s recommended to have each operator of AirCleaner be individually tested to
determine the individual’s reaction times — for both audio and video reactions. All
humans have a slightly different reaction time to visual versus aural stimuli;
AirCleaner therefore provides a separate reaction parameter for video and audio —
and for each of the two human screeners.
Testing methods vary widely, but to ensure a proper test is performed, be sure to
follow these guidelines:
•
Test visual reaction separately from aural reaction; perform two separate tests.
•
Use test footage never seen or heard by the human screener being tested; and
make sure it’s of sufficient length; at least 15 minutes or longer.
•
Use test footage in which the violation sequences are placed in random locations
inside the test footage.
•
Make sure the violations follow the flow of the scenes being depicted; violations
that are completely out of context will provide false reaction time, since the
operator will be reacting to the out-of-context nature of the violation.