Bandwidth vs. Image Quality Shootout 2011

Author: Benros Emata, Published on Jul 23, 2011

When thinking about maximizing image quality, resolution is usually the first thing that comes to mind. However, resolution is not the only factor that impacts quality. The amount of bandwidth available and used can have a dramatic impact on image quality. In this report, we examine bandwidth and the effect that it has on quality across numerous cameras.

Which Image Quality is Better?

To better understand image quality, let's start by examining two samples of the same scene side by side:

Consider two questions:

  • Which camera has higher resolution? A or B?
  • Which camera is better? A or B?

It is pretty obvious that the image from Camera B is better so this should be a simple case.

The reality is that those images are from the same camera at the same resolution and frame rate (720p/30). All that was done to the camera was changing the Constant Bit Rate target from 512 Kb/s to 8 Mb/s.

Factors Impacting Quality

Even with the same resolution, two common settings impact quality:

  • Bit Rate: Most cameras can have their bit rate adjusted to specific levels (e.g., 512 Kb/s, 2 Mb/s, 8Mb/s, etc.)
  • Quantization Level: Most cameras can have the level of compression adjusted (often called a quality or compression setting with options from 1-10 or 0-100)

Typically, these are mutually exclusive. If you lock in bit rate, the camera will automatically adjust the quantization level to not exceed the bandwidth set. Vice versa, if you set the quantization level, the camera will automatically change the bandwidth consumed to make sure the quality / compression always stays at the same level.

Our Test Process

We wanted to better understand how changes in these two factors impact video quality. To do so, we did a series of tests with three HD cameras: the Axis P1344, the Sony CH140 and the Bosch NBN-921.

For the bandwidth tests, we tested each camera at the following levels:

  • 512 Kb/s
  • 1 Mb/s
  • 2 Mb/s
  • 4 Mb/s
  • 8 Mb/s

We did this across a series of scenes to see how quality would vary in different conditions:

  • Daytime Indoors (300 lux)
  • Nighttime Indoors (.5 lux)
  • Daytime Intersection

Finally, we did a similar series of tests varying the quality level of a VBR camera (the Axis across 0, 30, 60 and 100 levels) to better understand changes in quality and bandwidth consumption.

Questions We Considered

Here are the questions we considered and answered inside the report:

  • When changing bit rates, how much are image details impacted?
  • How much quality differences exist among manufacturers at the same bit rates?
  • How do manufacturer streaming methods differ? How does that impact quality and performance?
  • What is the 'optimal' bit rate to use?
  • When should you consider using higher bit rates?
  • When adjusting compression levels, how much does bandwidth consumption and image quality vary?
  • What is the 'right' compression level to use?

**** ******** ***** ********** ***** *******, ********** ** ******* *** first ***** **** ***** ** ****. *******, ********** ** *** the **** ****** **** ******* *******. *** ****** ** ********* available *** **** *** **** * ******** ****** ** ***** quality. ** **** ******, ** ******* ********* *** *** ****** that ** *** ** ******* ****** ******** *******.

Which ***** ******* ** ******?

** ****** ********** ***** *******, ***'* ***** ** ********* *** samples ** *** **** ***** **** ** ****:

******** *** *********:

  • ***** ****** *** ****** **********? * ** *?
  • ***** ****** ** ******? * ** *?

** ** ****** ******* **** *** ***** **** ****** * is ****** ** **** ****** ** * ****** ****.

*** ******* ** **** ***** ****** *** **** *** **** camera ** *** **** ********** *** ***** **** (****/**). *** that *** **** ** *** ****** *** ******** *** ******** Bit **** ****** **** *** **/* ** * **/*.

Factors ********* *******

**** **** *** **** **********, *** ****** ******** ****** *******:

  • *** ****: **** ******* *** **** ***** *** **** ******** ** specific ****** (*.*., *** **/*, * **/*, ***/*, ***.)
  • ************ *****: **** ******* *** **** *** ***** ** *********** ******** (often ****** * ******* ** *********** ******* **** ******* **** 1-10 ** *-***)

*********, ***** *** ******** *********. ** *** **** ** *** rate, *** ****** **** ************* ****** *** ************ ***** ** not ****** *** ********* ***. **** *****, ** *** *** the ************ *****, *** ****** **** ************* ****** *** ********* consumed ** **** **** *** ******* / *********** ****** ***** at *** **** *****.

Our **** *******

** ****** ** ****** ********** *** ******* ** ***** *** factors ****** ***** *******. ** ** **, ** *** * series ** ***** **** ***** ** *******: *** **** *****, the **** ***** *** *** ***** ***-***.

*** *** ********* *****, ** ****** **** ****** ** *** following ******:

  • *** **/*
  • * **/*
  • * **/*
  • * **/*
  • * **/*

** *** **** ****** * ****** ** ****** ** *** how ******* ***** **** ** ********* **********:

  • ******* ******* (*** ***)
  • ********* ******* (.* ***)
  • ******* ************

*******, ** *** * ******* ****** ** ***** ******* *** quality ***** ** * *** ****** (*** **** ****** *, 30, ** *** *** ******) ** ****** ********** ******* ** quality *** ********* ***********.

Questions ** **********

**** *** *** ********* ** ********** *** ******** ****** *** report:

  • **** ******** *** *****, *** **** *** ***** ******* ********?
  • *** **** ******* *********** ***** ***** ************* ** *** **** bit *****?
  • *** ** ************ ********* ******* ******? *** **** **** ****** quality *** ***********?
  • **** ** *** '*******' *** **** ** ***?
  • **** ****** *** ******** ***** ****** *** *****?
  • **** ********* *********** ******, *** **** **** ********* *********** *** image ******* ****?
  • **** ** *** '*****' *********** ***** ** ***?

[***************]

Key ******** *** ***************

  • *****, *******, ******* *********** ***** **** ********** ********* **** *** kb/s ** ***/* ****** *** ****/** *******. ***** ********************* ****** ******* ***/* *** * **/*.
  • ********* ***** ******* ****** ******* ** *** **** *** **** setting ** *** ******** ** ************* ****** ** *** **** adjust *** ****, ***** **** *** *********** ******.
  • ********* ********** ******* **** ** ** ***** ******* ****** ** low-light ******, ***** ***** ******* *** ******* ******* ** ******* light.
  • ********* ***** ** **** * ******* ****** ** ***** **** (i.e. ***** ****** **** ** ***** ******** ** *** ***)
  • ********* ******** * ******* ******** ****** ** ****** ******* ****** static ****.
  • ** ***** **** ********** ***-***** *** **** ** ******* ***** details, *** *** ***** ******** ** ** ** ** ***** high (*.*. ***** **** ***** ** *****). **** ** * large ***** **** ***** ************* ******** ****** ****.
  • ************** ** ***, *** ***** ********* *******, ****** ****** *** three *************. **** *** ********* *** ** ***** ** '****' in *****-****. ****'* *** *** ************, ******** ***** **** ** be ****** **. *****'* *** ******* ****** ***-***** ** **** modestly **** *** **** ******* ***-****. ***** ***** *****, ***********, be ****** **.
  • *** **** *** *********** ******, *** ******* ** ******** * good ******* ******* ********* *********** *** ***** *******. ***** *********** levels (*.*., *) ******** ********* ***********.

** ***** ** ***** ******** ** ********* *** *********:

  • *** ****/** *******, * **/* ***** ** ** *** '***** spot' ********* *******, ********* *** **** ******* *** ********* ***** across *** * *******.
  • ********** ********* *********** **** * **/* ** * **/* **** capture ******** **** ******* *** **** ******** ********* *********** ** 2TBs *** ***** *** * ************ ********* ********. *** **** users *** ******, **** ** ****** *** ***** *** ****.
  • ** * **** ******* *****-**** ** *******, ******** ******* **** support * **** '************' *** ************** (*.*. *** **** ***** or ***** ***-***). *** **** *****'* *** **************, *.*., *** drop ******.
  • ** ********** ***** ******* ****** **** *** ** **** *** concern ******** ***
  • ******** *** ** ****** ********* ***-***** ** ******* ******** ********* spikes
  • ** ***** *** ** ****** ********* ***-***** ** ** **** surveillance (**** ***-***** *** ****-*** ***** ** ***), ******** * slight ** ******** ******** ** *********** ****** ** ******** *** degree ** ********* ******. **** ******** ******** *** **** ***/** increasing ********.

Why **** ********* ****** *******?

****** **** **** ********* *******:

**** ******* *** **** *** ********** *** ***** **** **** not **** **** *** ********* ** ******* **** ****** ********. These *** **** ******* ******* *** ****** *** *** **** automatically ****** *** ****** ** *********** (** ****** *******).

********* #*:

*** **** ******* *** *****, *** **** ********* ** ***** to ****** *** *****. ** *** ** *** **** ****** bandwidth, ******* **** ****** - ******. **** ******** ** *** visible *** ******* ********* **** **.

********* #*:

*** **** ******* *** ******** ** *** *****, *** **** complex *** ***** **. **** ***** ** **** ****** ******* through *** *****, ****** ******* ** *** ****, **** ******* or **** ******* ***** ** *** *****. *** ******** ***** is ******** * ****** ** * ***** ****. *** ** any ** ***** ***** ******* *** ********** **** **. **** complexity, **** ********* ** ******.

********* #*:

**** **** *** ********** *** ***** **** ***, *** ****** must *** * ******** *********** *****. **** ***** ***** ******* intuitive *** ** ** *** ****. ***********, **** ** ******* called************. *********, ** ** ******** ** ** *** ****** ******* factor. **** ***** **** *** '*****' *** ***********. **** ****** in ******* ****** (*****, ****-*, ****, ***.). *.*** *** * ***** ******* **** 0 ** ** **** * ***** ******* *********** *** ** being ******* *********** (*******: *************** *** ***** **** *****).

********* #*:

*** **** ********* ********* *** *** **** ******* *** *****, the **** ******* **** ** ** ******* (*.*., *** ****** the *********** *****). ***'* **** ** **** ** ******:

**** ******* ** **** *****, ****** *** *********:

  • *** ** ****** ******* ******, *** ****** ** *********** / quantization********. *** ****** *** ******, *** **** ******* ***** *******.
  • *** ***** ** ********* ********* (**** **** **** ***).
  • ** *** ********* *****, *** *** ** ****** *** *** intersection **** *** ****** **** ******* *** ************ ** * more ******* ***** (******* **** *** ***** ** ****).
  • ** ********* *********, *** ***** *** ****** ******* ******** (**** carefully ** *** ****** ****** ********).

*** *** ******** *** ***** ******* **** **** *** *******. Export **** **** **** *** *** *** ******* **** ************. ** **** *** ****** **** *** ** *** ** help *** ********** **** ** ***** ** *** *** ********** the ***** **.

Optimizing *** *** *** ** ****, *****, *** ****

** **** ***** ** ******* *** ** ******** *** *** VBR ******** ****** *** *** ********** ** *** ***** ******* used ** *** *****. *** ***** ** ****** ***** *** group, ******* ** ******** **** * *** *** *** ******. One *** ***** ** **** ** **** *** *****'* *** implementation **** *** ***** *****-***** ** ** ***** ** ****** in. ** ******** **** *** ***-*** *** ***** *** ******* will **** ** * ********* *****-****. ** *** **** ******* of *** ***** ** ******* *** ***** ******* ** ****** to *********** *** ********* ************ ** ***** ************/***** ******** *** implementations.

CBR ***** ******* ******** (**** *****)

** **** ********* ** ******* *** **** *****'* ***** ******* at **** ********* *** ***-***** (*.*, *, *, *, *** 8****) ****** ***** ********* ****** (****** ***-*****, ****** *******, *** busy ************). ****** *** ********* ****** ** ****** ****** *********** in ******. *** ****** ** ********** ** ***** ** *** image ** ******* *** ********* *** ****** ***********.

*** *****'* *** **** *** **** ********** ** ******** ***-***** close ** *** **** ******* ***-*****: *) ***** ******; *) increase ***********. *** ****** ** **** *** ******** ** ****** operate ***** **** ****** ***** ** *****. *** **** ***********, image ******* **** **** ** **** **** ****** *** ******** of **** ******* *** **** ******** ** ***** *** *************** (e.g. **** ***** *** ***** ***-***), ******* *** ***** ****** for *** ********** ** ****** ** **** ** ********** *** compression *****.

** *** ***-***** ******** *********** ********* *** ***** ********** ** 512kbps *** ***** *** ***** ** ***** ** ** ***** and ******. *******, *** ********* ****** ** ********** ***-***** ** quite ******* ** *** *****'* ***-******* ******** ******* * ********** low ***** ***** ** ********* ***** *******.

** *** ****** ******* ********, *********** ********* ******** ******** ** the ***-**** *********. *******, ** **** ****-*** *** ********** ****** FoV *** ********** ******* *** ** ****** ********* *********** ** the ********* ***** **. ************, * ******* ** ******** ***-**** and *** ** ******* ** *** ***** *****, ***** ********** increases ** **** ******* *** ****, ****** ** ** ****** in *****-****, *** ****** ******* ** *** ****** ***-**** *** image *******.

** *** ****** ********** ************ *****, *** **** ******* ******* is ******** ** ********** ********* ** **** ******* *** **** are *********. *******, * ******** ******* ** ******** ***-**** *** resulting ***** ******* ***** ** *** ****** **** ******* ***** is ****** **** ** **** **** ******* ***. ******, * fairly ********** *********** ***** ****** **** *** ***** ** ***** mark.

CBR ***** ******* ******** (***** ***-***)

** **** ********* ** ******* *** ***** ***-***'* ***** ******* at **** ********* *** ***-***** (*.*, *, *, *, *** 8****) ****** ***** ********* ****** (****** ***-*****, ****** *******, *** busy ************). ****** *** ********* ****** ** ****** ****** *********** in ******. *** ****** ** ********** ** ***** ** *** image ** ******* *** ********* *** ****** ***********.

** *** ***-*** ** ******* ***, *** ***** ***-*** ******** considerably **** *********** ********* **** *** **** ***** **** ** the **** ******* *****. *******, **** ** ******** ** *** NBN-921 ********* **** ****** ***** ***** **********, *** ****** *********** on ********* ** *********** ***** ** **** ***** *** ***.

******* *** ***-***'* ******* ******** ** */***, ****** *** ***** to ****** ************ ***** *** ******* ***-***** ********** (~*.* ***). As **** ****** ** ** ********* *********** *** ******** ******* the ********* *** ***-**** **** ** **** ********** ***********.

** *** ****** ******* ********, *********** ********* *** ******* ******* at *** ******* *** ***** ***. ** *** ***** *****, compression ********* *** ******* *** ****** *******, *** ***** ******* to * ****** *** *** ****/*** **** ** ** ******. Despite ******** ***-***** ********** ** **** ** *** ***** *** 8mbps ****, *** ***** ******* ***** ** *******, **** ****** to ** **** ** ****** *** *** ********** ********* ********.

********* *** '**********' *** ******* ******** ** *** ******* **** in *** ******* ************ *****. *********, *** ******** ***-**** ** only ~*******. *** ***** ***** ****** ** ****** ************ *** manifests ** ****** ***-**** (*.******) **** **** ******* ** *** user ******* ***. ***** ******* ******** ** **** ********** **** towards *****. ***** **** * ** ************* ****** ********** ******** ************ ** *** *****.

CBR ***** ******* ******** (**** **-***)

** **** ********* ** ******* *** **** *****'* ***** ******* at **** ********* *** ***-***** (*.*, *, *, *, *** 8****) ****** ***** ********* ****** (****** ***-*****, ****** *******, *** busy ************). ****** *** ********* ****** ** ****** ****** *********** in ******. *** ****** ** ********** ** ***** ** *** image ** ******* *** ********* *** ****** ***********.

** *** ***-***** *********** *********, *** ********* ****** ** ********** bit-rates ** ***** ******* ** *** *****'* ***-******* ******** ******* a ********** *** ***** ***** ** ********* ***** *******.

** *** ****** ******* ********, *********** ********* ******* ***** ********** until *** ***** ****. ******** **** ******** ** ******** ******** at **** **** ******* ***** *** *****, *** ********* ****** is ***** ******* ** **** ****** ***.

** *** **** ******* ************ ********, ** *** ******* **** the ****** ** ***** ********* ** ~******* (~**% ***** *** user ******* ***). *** ***** ** ***** ***** '******' *** clears ** ****** ********** ** *** ***** *** ***** ****. Unlike *** ****** ****, *******, ***** ** ***** ***** * reduction ** *********** ********* ***** **** * ** *****.

VBR ***** ******* ******** (**** *****)

** **** ********* ** ******* *** **** *****'* ***** ******* at **** ********* *** *********** ****** (*, **, ** *** 100) ****** ***** ********* ****** (****** ***-*****, ****** *******, *** busy ************). ** ** *** **** ******* *****. ***** ******* means **** *********** (*.*., *) ***** ******* ******* **** **** compression (*.*., **, ***).

****** *** ********* ****** ** ****** ****** *********** ** ******. The ****** ** ********** ** ***** ** *** ***** ** enlarge *** ********* *** ****** ***********.

** *** ***-***** ********, *** *, ** *** ** *********** levels ****** ** ****** ** *********** ***** *******. *** *** point ** ******* ** *** ********* *********** ** ********* ***********. Notably *** * *********** ***** ******* ** ** ************ **** ~24mbps; ********** *********** ** ** ***** ******* ** ** ********** ~12mbps *********. ** ** * **** ********** ~*.***** ** *******. Thus, ***** **** * * ** ** *********** ***** ******* in ****** ******* ****, *** ******* ********* *********** ** ~**%.

** *** ****** ******* ********, *** * ** ** *********** change ******* ** *** **** *********** ********* **** (~**%) **** little **** ** ******* ******* ** *** *****.

*** ************ ******** *** **** ******** ** *** ****** ******* (0 ** ** ******* ** ~**% ********* ******* **** ****** loss ** ***** *******).

** ** ********* ** **** **** *** '*****-****' *** ***-***** and ******-*******/************ *** ** ** ********* *********** ****** (~** *** low-light, *** ~** *** ******-*******/************). ************ **** **** ** ********** and ******** *** ******* ** **** ******* *** ******* * more ********** ************ ********.

***** ** * ***** ** *** *****'* *********** ***** **. Bandwidth (* ******):

*** *** ******** **** ** **** *** **** *********** **** in ********* *** *** *** ****-*** ****** (****** ******* *** intersection) ****** **** * ** ** ***********, ***** *** ***-***** curve ********* ** * ******** ******* - *** ****** ********** until *** *** *********** *****. *** *** '****-***' ****** ******** to * ******** ******* (* ********** ******* ** ~*.*****) ** *** ** *********** *****.

***** ** ** ************* ** **** ***** * ****** ******* a ******* ** ***** ***** ****** ********** *** *** *** find * **********, *.*. ** *** ** ***** ** ***********. Of ****** ********** *** **** ***/** ********** *** ******** *** also **** ******** ********* ****** ** *** ***-***** ***********, ** well.

***********

******* **** ********** ** */*** ******* ******** *******. **** ****** lens *** ******** ** ******* * ******* **** *** ******** (lens ***** ~*********).

**** *** *** ******* **** ** '******* **. *********' *****:

  • **** *****(****** $***) - **** */*; */*" ****; **.* ******** ; 0.3/0.05 *** (*****/**)
  • ***** ***-***(****** $***) - **** */*; */*" ***; **.* *****; *.*/*.* Lux (*****/**)
  • **** *****(****** $***) - **** */*; */*" ****; **.* *******; *.* Lux (**)

** *** *** *******, *** ***** ******* ******** *** **** scene ** * ***** **** ******* *** ***-****. *** ***** was ******** *** **** ** **** ********* *** ***-***** (*******, 1mbps, *****, *****, *** *****). **** ****** ***-***** *** *** were ********** *** ********.

** *** *** *******, **** *** ***** *** ****. *** same ***** ******* ****** **** ** *** ******* **** ********. Each ***** *** ******** ** **** ** **** *********** ***** settings (*, **, **, *** ***).

**** *** ***** *** ******* ***/*** ********:

  • **** ***** - *** ** * *********** ** ** (* - ***)
  • ***** ***-*** - *** **** * ****** ** **** **** and * ******* ** ***** ****
  • **** ***** - *** **** * ******* ** *****
Login to read this IPVM report.
Why do I need to log in?
IPVM conducts unique testing and research funded by member's payments enabling us to offer the most independent, accurate and in-depth information.

Related Reports

Arecont Vision MicroDome Duo Tested on Feb 14, 2017
Arecont Vision is back with another multi-head camera, this time thinking smaller with the MicroDome Duo, a two-imager model, with the tagline...
LAST DAY - Camera Course Winter 2017 on Feb 02, 2017
[NOTE: Today, Thursday is the last day to register.] Learn video surveillance and get certified. IPVM provides live online classes, recorded...
Arecont Lowest Favorability Results on Jan 25, 2017
Given Arecont is 3 time defending integrator choice for worst camera manufacturer, it should be little surprise they had the lowest score in the...
IP Networking Course January 2017 on Jan 12, 2017
This is the only networking course designed specifically for video surveillance professionals plus it includes live training, personal help and...
Avigilon Pro 4K Camera Tested on Jan 03, 2017
Avigilon is best known for their large sensor, high megapixel cameras. But with new offerings from Sony and soon Axis, the questions is how well...
IP Networking 2017 Book Released on Jan 02, 2017
The new IP Networking Book 2017 is a 197 page in-depth guide that teaches you how IT and telecom technologies impact modern security systems. The...
Hikvision No on H.265 But Pro On H.265+ on Jan 02, 2017
Hikvision said H.265 was a 'solution in search of a problem' a half year ago but now they are getting bullish, embracing H.265+. In this report,...
Surveillance Cameras 2017 Review on Jan 02, 2017
This report concisely explains the developments and most common options for surveillance cameras offered in 2017, including resolution, H.265, HD...
Calculating Video Surveillance Storage / Bandwidth on Dec 29, 2016
Calculating surveillance bandwidth is complex, and inexperienced users can easily underestimate bandwidth, leading to reduced storage durations...
IR Video Surveillance Tutorial 2017 on Dec 21, 2016
Almost all surveillance cameras perform worse in low light than they do in the day time. One of the most common techniques to overcome this is to...

Most Recent Industry Reports

Hikvision Pyronix Releases 'Huge' New Panel on Feb 27, 2017
Hikvision's 2016 acquisition Pyronix has been touting their 'huge' new large system panel. Indeed, the new Euro 280 claims features that are better...
Bosch Favorability Results on Feb 27, 2017
Bosch is one of the most well known brands in the industry and they have combined recently with Sony in video surveillance. But how has Bosch...
ADT CEO: My Daughters Better At Installs Than Most 20 Year Techs on Feb 27, 2017
Times have changed. At the Barnes Buchanan conference, ADT's CEO Tim Whall made an interesting and, surely to some, controversial observation....
Avigilon Favorability Results on Feb 27, 2017
One of the fastest growing companies has turned into one of the rockiest, as cooling growth, management turnover and a roller coaster stock price...
Honeywell Sues Alarm.com For Violating Anti-Trust Laws on Feb 24, 2017
Is Alarm.com about to dominate the smart home software market? That is what Honeywell alleges in its new lawsuit, first reported by...
Axis: "Everything is IP" - False on Feb 24, 2017
Axis is congratulating itself, with executive Fredrick Nilsson declaring: "Now the conversion is all done and everything is IP and analog is...
Advertising Like Avigilon at the ISC West Airport on Feb 24, 2017
Avigilon has grabbed a lot of attention over the last few years advertising at the Las Vegas airport when attendees fly in. But how does that...
Artificial Intelligence Robot Assistant (ACTi) on Feb 23, 2017
Has artificial intelligence come to the video surveillance industry? ACTi has released 'SARA' which it bills as an 'AI assistant that brings...
Cutting Costs 70% Using Milestone With HD Analog on Feb 23, 2017
HD analog and enterprise VMSes are often thought of as being on opposite sides of the spectrum, with HD analog best for small jobs due to its low...
Dahua 4K HD Analog Cameras Announced on Feb 23, 2017
HD analog has been gaining popularity (even if Axis hopes otherwise). Last year, HD analog's max resolution doubled from 1080p to 4MP (see our 4MP...

The world's leading video surveillance information source, IPVM provides the best reporting, testing and training for 10,000+ members globally. Dedicated to independent and objective information, we uniquely refuse any and all advertisements, sponsorship and consulting from manufacturers.

About | FAQ | Contact