Digital Noise Reduction (DNR) Guide
Visual noise spikes camera bandwidth usage in low-light. Digital noise reduction (DNR) aims not only to reduce noise but to improve video quality and minimize bandwidth usage.
In this 10-page guide, we explain the effects of digital noise reduction on image quality and bandwidth consumption, as well as noise reduction methods used in video surveillance, examining:
- Digital Noise Reduction Basics
- DNR Methods
- Spatial Digital Noise Reduction
- Temporal Digital Noise Reduction
- 2D vs. 3D Noise Reduction
- Manufacturer DNR Controls
- DNR Image Quality Improvements
- DNR Motion Blur Issues
- Camera Model DNR Motion Blur Performance
- Motion Blur Vs. Noise Tradeoff
- DNR Bitrate Reductions
- Smart Codec Impact On DNR
Key ******
***** *** **** *** ********* **** this *****:
- ***** *** *** *** ******* ** digital ***** ********* (***), ******* (****** frame) *** ******** (*****-*****), *** **** are ***** ******** *** ******** ** as "** ***."
- *** *** ******* ***** ******* *** lower ********* ** ****** ******** **** efficient, *** ******** *** **** *** cause ****** **** ** ****** ******.
- ***** ** **** *******, **** *******' default ******** ***** *** **** *****-*** of *****, ***** *******, *********, *** motion ****, *** **** ** ******* in **** ******* ****** (******** *** ***** **** *********** **** *******).
- ******** ******** *** ******** ** *** overall **** ****** ****, *** *** increased ***** ***** ******* *** ***** quality ***** ** ****** *******.
- ** *** *****, *** (** ******* settings) ******* ********* ** **-**% ** night ******** ** ********* ** ** setting ** ** ******* ******.
** ****** *** ****** ** *** and **** ** ***** ******* ** detail *****.
Digital ***** ********* (***) ******
** ***** ****** ********, ******* ******* to **************** ******** *** ********** ** images ************** **** *******.
*******, ***** *** * ********* **** effects:
- ******* ***** ** *** ***** **** obscures **** ******* (***** ** ***** better **** *** *********** ******* **** - * ********** **** *****)
- ******** ********* *********** ******* *** ******* sees *** ******* ***** ** ****** objects **** *** **** ********* ** encode.
******* ***** *********, ** *** **** states, **** ** ****** ******* ***** present ** ***-***** ************ ******. *** example, ** *** ***** *****, *** subject ** *** **** ** ***** with *** ********. ***** ******** *** face *** **** ** *** **** chart, ***** *** ****** ** ****. However, **** *** *******, *** **** can ** **********, ******** ******* *** be ****, *** ******* ***** ** the ***** ****.
Methods ** ***** *********
*** *** *********** ***** ** *** are ********* ******** ** ** ******* and ********. **** ***** ** ***** as "**" *** "**."
Spatial ***** *********
******* ***** ********* ******** ******* ** adjacent ****** ** *** **** ***** to ********* **** ** ***** *** averages ***** ****** ** ****** *** image. **** ********* *** ****** *** sharpness ** *** ***** ** **** levels, *** ** ******** **** ************* power *** ******** ***** ******* **** temporal **********. *******, ******** *** ********* offers ****** ***** ********* ** ***-****** images **** *******.
Temporal ***** *********
******** *** ******* ******* *** **** pixels ******* ****** ** **** *** pixels **** ** *** ****** ************ from ***** ** *****. ****** ** those ****** *** **** ******** ** smooth *** *****.
*******, **** ****** *** ****** ** noise *** ******* ******** ********** ******* of *** ***** ****** ** ***** values **** ***** ** *****. ******* of ****, ******** ***** ********* ***** causes ****** **** *** *********, ********* later ** **** ******.
3D ***** *********
******, ** ********** ******* *** ******* and ******** ******* ********* * ******* image **** **** ****** ****, *** are **** ******** **** ** ***** surveillance. ****** ** ***** ******* *** bitrates **** ** *** ****** **** manufacturer ** ************ *** ******* ** the *********** ** **** **********.
**** **** *** ***** ** *** temporal *** *** ***** **** *************** in ***** ************ **** ****** ** is *** *********** *******. ********, ******* DNR ** ***** ****** ** ***, though ** *** *** *** ****** spatial ** ******** ***** ********* **********.
Manufacturer *** ********
**** ************* ** **** *** * combination ** ******* *** ******** **********, though ******* ** **** ** ****** presented ** *****. **** *****, *** is ****** ********** *** "**/***" ***/** a ***** ******, **** ** *** Hikvision ***** *****. ***** ** ** clear ********** ** ******* *******, ********, or **** ******* *** ***** ******** here:
*******, **** ************* ***** ******** ******* of ******* *** ******** *** ***** allows ***** **** ******* **** ******** for ***** ******** ******, **** ** in **** ***** ******:
***, ******, **** ***** *** ********** of **** ******** *********, ***** ** is **** ****** ** ******* ******** image ******* *******, **** ** *** Avigilon ****** ***** *****:
DNR **** ******
***** *** ****** ***** ********** ** many *****, **** ****** *** ********* blur ** ****** ******* ****** ********** ***** *********, ***** ****:
DNR **** ** ****** *** *******
** *** *******, ****** *** ******* suffer **** ****** **** ** *** light ******, *** *** ******** *** light ****** ***** ******** ******** ******. Shown ** ******** *** ***** ********, **** *** "****" ********** **** Q1798-LE ******** ****** **** ** ~* lux, ***** ******* *** "*****" ********** produced ************ **** ******** ****** *** reduced *******.
***** ****** ******** ** ******** ***** levels (*.*. * *** *****), *** were ******* ** **** *******.
*** ******** *** ***** **** *********** **** ******* *** ******** ** these *** ***** ******.
Reducing ****** **** ********* *****
***** ****** *** ******* ******* **** blur **** ******** ***** ********* ** used, ******** *** ** ******** ******** specifically ** ****** ****** **** ********* results ** ** ******** ** ******* noise ***** *********** ******** ******* *******.
*** *******, ** *** ****, *****, the *******'* **** *** **** *** blurred ** ******** ********* ****** ** temporal ***** *********, ********* ******* *******. With ******** ***** ********* ****** ****, right, ******** ******* ******** *******, *** his **** ******* ******** ** ******* noise, **** ************ ******* ***********.
******* ** ****, ***** ** ********* that ***** ******* ** ****** ******** noise ********* ** ****** *** **** in ******** ******, ** ** ****** that ******* **** ******* **** ********, if ** ***.
Intelligent ***
**** ******* *** ******* "***********" ***, which ******** ********* ** ***** ****** (discussed *****), ********** *** ** ****** areas ** *** *****, ***** ******** it ** ****** ******* ** ****** motion ****.
*** *******, ** *** ***** *****, the ****** ************* ******* *** ****** on *** ******* ****** ******* *** scene. **** ****** ********* ****** **** caused ** **** *** ****** *** adds **** ******* *****, **** ****** the *******.
*********** *** ** ** ******** *******, but **********, **** ***** ************ ******** **** *********.
DNR ******* **********
******* ******* **** *** ************* **** smart ****** *******, ** ***** **** DNR ******* ******** ** ** ******* of ~**% ** * ~*.* *** scene. **** *******' ******** ********* ** 70-90%, **** *** ******* ********** ** ~25%.
**** *** ******** ** * ******** of ***** ****** ** **** ******* tested, ** **** *** ******* ***** bandwidth **** ***** ****** *** ********. For *******, ******* * *** * produced *********** *** **** ******* **** DNR ** ** *** **** ***** codecs **** ********, ***** ****.
************* ** *** ************ ******* ******* DNR ****** ** ***** ***** ** their *************, ** **** ******* ** place ** ******** ** ********* ****.
* ***** *** ***** **** ** issue ** *** *** **** ******.
**** * **** ** **** ******* :
** *** **** ** *** ***** you *** **** **** *** **** camera *** * **** ****** ******* speed **** ** **** ******* ***** a ***, ******* *** ***** *** a ***** ***** ** *** **** (because ** ** ********** ****** *** capture). * ***'* *** **** ********** that ********** ***** ** *** **** during * **** ***** ** ********, but ** ** ***'*, **** ******* captures **** ********* ****** ** *** cycle ***** *** ** ********** ****.
*** ***** ***** ** **** **** saturated ** *** ***** ***** (**** and *****), ***** ******** **** *** camera ** ****** ********** *** *** scene ** ***** ** ******* ***** to ***** *** ****/******* ***** *** get * **** ********* ***** *** a ****** ******* ** *** ***. My **** ** **** *** **** is**********, ********* *** ******* *********** *********, which ******** **** *** ******* ***** can ** *********. * ***'* **** the ****** ** ********, *** * don't **** ** *** ******** ***** it ********** ** *** * ****** shot ** *** ***** ******, ** just ***** ** ** **** ***** is ********* *** * ****** ******* from **** ******.
* **** *** *** ** *** word "****" ***********. ** ** *******, the ******* *** * ****** *******, but ***'** ******* **** ******** **** Axis ** "****" (*** **** ** a **** ********** ******** ** ***** DNR, *** *** * ****** ******). But ****, ** *** ********* ************, we're ** ****** ******* ** **** what ****** ********* **** *******. * am ******** **** ** ******* ***'** using ********* *** ******, *** **** didn't ****** *** *******/******.
********* ******** ** (********* **** ****** a **** *******): * *** **** experimentation ** * *** ****** * once ****** **. ** *** ******* speed ** "****" ** * *** light *******, ** ***** ** ***** "stacking" ****** ** *** **** ** see ********** ****** **** *******. **** is ********* *** ***** ** ***** the ****. ******** *** ***** ** spatial (*******) ** *** ****** ***** the **** ***. * ***'* **** if ****** ** ***** **** *****, but * ***** ** ***** ** a **** ******** ** *** ***.