Sony SNC-CS50P - Manual (Page 11)

11
Privacy concerns have become an important worldwide
issue in all aspects of society. Likewise, in surveillance and
monitoring applications, privacy protection is not only
desired but sometimes mandatory as defined by laws and
ordinances.
The Spherical Privacy Zone Masking function incorporated
in the SNC-RX550 and SNC-RZ50 Series of network
cameras is a sophisticated masking method that responds
to these requirements.
Privacy zone masking is a feature in surveillance
applications that is used to protect personal privacy by
masking private areas in the camera‘s field of view, such
as windows and doorways that are within the monitoring
area but not subject to surveillance, and other private
property. Many manufacturers incorporate a privacy zone
masking function in surveillance recorders and monitoring
software, but may not incorporate this function in
cameras. However, in networked video surveillance
applications, privacy zone masking on the recorder or
processing device poses a major security concern, because
images captured by a camera are streamed over a
network before the mask is generated. What’s more,
delays can occur when processing masking data on
recorders or with software because the mask is generated
after streamed image data is received.
To mitigate the risks associated with this type of
processing, the Sony SNC-RX550 and SNC-RZ50 Series of
network cameras incorporate the Privacy Zone Masking
function in the camera itself.
With these network cameras, the masked areas of the
image are dynamically interlocked with the camera‘s
Pan/Tilt/Zoom (PTZ) movements for comprehensive image
masking (Fig. 1) – this is called “Spherical Privacy Zone
Masking.” The spherical masking mechanism works as
follows: when you specify the area and color of a mask,
the camera produces a signal to generate an image that
replaces the data for that area with a mask. This data,
along with the camera‘s PTZ settings are stored in the
camera‘s memory. When the camera pans, tilts, and/or
zooms, the PTZ settings are updated, and the mask is
repositioned so that it continues to cover the original
masked area. This data is updated every 50 ms so that
regardless of the PTZ speeds, masked areas within the
image remain covered. A maximum of eight masking
areas and one of nine masking colors can be set for each
camera.
Spherical Privacy Zone Masking
Updates PTZ position data every 50 ms
Privacy Zone Masking area is set.
Privacy Zone Masking area after PTZ movement.
Masking area
Movement of masking area
Monitor
Monitor
Fig. 1 Spherical Privacy Zone Masking