3vr E-Series SmartRecorder, Installation Manual

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3VR SmartRecorder Installation and Configuration Guide
CCTV Video
Many existing camera positions are designed for alarm assessment and activity monitoring. Those cameras must
be adapted for use in facial analysis. Existing infrastructure can and may be used for facial analysis but it must be
optimized for use in meeting the imaging guidelines enumerated in this document.
The remainder of this section is a lengthy but important treatment of design and deployment options for CCTV video use.
Environment:
First, examine the physical layout of the facility to identify natural “choke points” – areas where subjects will
appear within a limited field of view and are most likely to look “straight-on” toward the camera(s). Ideal choke
points include entrances and hallways. This area should be free from any obstructions that might come be
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tween the camera and subject, (including transparent barriers that can create glare/reflection problems). Also,
these areas should be devoid of distractions that may entice subject to look away from the camera while passing
through. Ideally, subjects will spend 3 seconds passing through a choke-point area.
The recommended width of a single-camera choke point is 4 feet, with a maximum width of 4½ feet. Areas
wider than 4½ feet require multiple cameras positioned so the lines of sight slightly overlap. The degree of over
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lap should enable each camera to capture the full face of a subject who passes halfway between them, instead of
each camera capturing only half the subject’s face.
Scene lighting must be sufficient to produce a clear, sharp image. Excessive background lighting, blooming or
shadowing conditions must be avoided.
Camera Positioning:
Cameras should be centered to
increase the opportunities to obtain
straight-on (perpendicular) face
images. In addition, the distance
from the subject should be the
greatest allowable (subject to lens
specifications that provide a proper
Field Of View - less than 4.5 feet, as
explained in Section 3). The further
the distance between camera and
subject, the longer the Depth of
Field – the area within which the
subject will remain in focus – thus
delivering more usable ‘face frames’.
Optimal full-facial recognition occurs
when a camera is mounted on a vertical line that is level with (and horizontally perpendicular to), the subject’s face.
Harsh camera angles are detrimental, and will seriously degrade the results.
While cameras are often mounted higher than the optimal face-level height, adequate Face Capture can occur
provided the maximum Vertical Angle of Incidence is less than a 20% slope, (see illustration below). The greater
the distance between camera and subject, the higher the camera can be mounted, while maintaining this
threshold.
Figure 1 – Ideal Camera Positioning