* Privacy Zone Masking keeps Surveillance Cameras from invading Privacy

During my research and posting on the increasing use of surveillance cameras, I have seen and taken note of the countless number of people throughout the world in an uproar about their privacy and civil liberties being violated. That being said, I found a pretty interesting explanation on “Privacy Zone Masking” on surveillance cameras, courtesy of Sony.

(2008, March)

In today’s security and surveillance installations, the protection of civil liberties is as important as the protection of customer assets. Therefore, the ability to “mask off” certain areas of a camera’s field of view – such as the window of a house – is essential. Sony’s privacy zone masking feature offers the optimum solution.

Protecting Privacy

When monitoring an area for security, there may be certain parts within the camera’s field of view that need to be kept private. A window or doorway to a house, for example. If these are not blocked out, security personnel could snoop on members of the public and infringe their personal privacy. And if this sort of activity is discovered, it could result in litigation against the company responsible.

Privacy zone masking is a feature that enables these areas to be concealed from view. It can be incorporated into any monitoring solution, typically within the recorder or the software. However, on certain models, Sony has integrated privacy zone masking to the camera itself.

This is the most secure method, as it eliminates all processing delays. The position of the mask is dynamically interlocked with the camera’s pan/tilt/zoom (PTZ) movements, so if the camera tilts up, the mask will move down accordingly – and the private areas of the image will remain concealed.

How it works

When installing a security solution, the customer and the installer will work together to define the privacyzones. These may include certain areas that have to be masked continuously, but also areas that vary according to the zoom of the camera. For example, if the camera is monitoring a large apartment block in wide-angle mode, there may be no requirement for masking. But if the camera zooms in, windows and doorways may come into view that then need to be hidden.

The installer will configure the cameras to automatically hide these areas with a mask, which can be adjusted in terms of its colour, size and aspect ratio. When satisfied that the privacy zones are properly protected, the installer will lock the mask data into the camera’s memory, along with the camera’s current PTZ settings. This mask data is protected by a password – known only by the installer – so security personnel are not able to remove or alter it.

From this point on, if the camera is panned, tilted and/or zoomed, the mask automatically repositions and resizes itself to ensure the hidden area stays hidden. It does this by comparing the camera’s original PTZ setting with its new PTZ setting. And because the comparison is done at a faster rate than the camera’s PTZ speed, there is no lag in the mask adjustment, so the hidden area is never revealed.


Privacy zone masking is an essential feature for wide-area security applications in which certain locations are prohibited from being monitored and/or recorded. And thanks to Sony’s unique approach of putting the functionality up-front in the camera, it can now be used without any concerns over breaches in privacy.

*1st picture shows Privacy zone masking area is set

*2nd picture shows Privacy zone masking area after PTZ movement

Privacy zone masking is available on the following Sony PTZ cameras;

  • SNC-RX530NB – 1/4″ CCD w/Exwave HAD, 360 PTZ IP, 18x Zoom, Black
  • SNC-RX530NW – 1/4″ CCD w/Exwave HAD, 360 PTZ IP, 18x Zoom, White
  • SNC-RX550NB – 1/4″ CCD w/Exwave HAD, Multi Codec, 360 PTZ Network, 26x Zoom, Black
  • SNC-RX550NW – 1/4″ CCD w/Exwave HAD, Multi Codec, 360 PTZ Network, 26x Zoom, White
  • SNC-RX570NB – 1/4″ CCD w/Exwave HAD, 360 PTZ IP, 36x Zoom, Black
  • SNC-RZ50N – 1/4″ CCD w/Exwave HAD, Multi Codec, 340 PTZ Network, 26x Zoom


(2008, March) Discretion Assured Thanks to Privacy Masking. Sony. Retrieved on September 26, 2008 from http://www.sony.co.uk/biz/view/ShowContent.action?site=biz_en_GB&category=NVMPTZCameras&contentId=1203501601074&sectiontype=Product&preserveContext=true

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