In a technical sense the term "noise" refers to any artifacts that occur when signals-including audio, images and video-from a source are transmitted or reproduced. One of the most common factors leading to noise in video is a low light level, and noise can obviously be a serious problem in video captured for security applications under such conditions. For example, noise can severely limit the ability to positively identify persons of interest or vehicle license plate numbers at nighttime video, or to effectively monitor dimly lit areas in an office or retail space. Noise reduction is thus a vital capability for any security camera to be used under low-light conditions.
Without 3DNR
There are two types of technologies currently in wide use to reduce noise in video, each with its strengths and weaknesses-2D noise reduction (2DNR) and 3D noise reduction (3DNR). 2DNR works by analyzing individual frames of video, identifying algorithmically and correcting those pixels that likely represent noise. 3DNR, on the other hand, additionally analyzes the differences between successive frames in order to adjust pixels and improve fidelity. 3DNR generally produces greater reduction in noise than does 2DNR, but with the drawback of tending to create motion blur on moving objects in the field of a view.
3DNR Solution: Combining 2DNR and 3DNR
In order to take advantage of the strengths of each type of noise reduction technology while avoiding its weaknesses, TISAN employs a combination of 2DNR and 3DNR. Since 2DNR tends to produce superior results for moving objects, it is applied to areas in the field of view where movement is present. Meanwhile, 3DNR is applied in static areas of the field of view. Besides enhancing video quality, TISAN noise reduction technologies provide other important benefits such as reduced video file sizes and prevention of false alarms caused by noise. It is TISAN’s seamless integration of the two types of noise reduction technology that makes TISAN’s cameras perform so extraordinarily well even in challenging low-light conditions.
