Privacy masking is a feature found in many IP cameras which are used to protect personal privacy by concealing parts of the image from view with a masked area. Examples of this use would be masking windows of domestic properties or car number plates which are not subject to surveillance.
It works as follows: You would select an area within the image, normally by drawing a square or rectangle directly onto the picture using the mouse. In some cameras, you can also specify the type of mask, whether it is formed from a solid colour or using a transparent pixelated effect. This mask will continue to cover sensitive areas of the image whenever users view the camera.
Some PTZ (pan-tilt-zoom) cameras also support privacy masking. When the camera is panned, tilted or zoomed, the mask is repositioned and resized so that it continues to cover the original masked area. This ensures the same object is always hidden from view regardless of PTZ position.