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

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...
Camera Course Winter 2017 on Jan 05, 2017
Learn video surveillance and get certified. IPVM provides live online classes, recorded videos, personal help, cutting edge education 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...
Video Surveillance Bandwidth Guide 2017 on Dec 16, 2016
Bandwidth is one of the most fundamental, complex and overlooked aspects of video surveillance. Many simply assume it is a linear function of...
Milestone: H.265 Not Ready For Prime Time on Dec 14, 2016
Hype for H.265 has been growing, but Milestone is recommending restraint, despite supporting H.265. In this note, we examine Milestone's position...

Most Recent Industry Reports

Vivotek Favorability Results on Jan 20, 2017
Financially, Vivotek is doing relatively well. The company did ~$130 million in 2015 revenue and 2016 revenue (through Q3 reported) was up more...
PR Firm Pleads Don't Scrap PR Spending on Jan 20, 2017
PR is not dying, warns pleads PR firm. Take 40+ year old industry PR firm LRG, who recently lamented the 'misconceptions' that: Traditional PR...
Getting Started With Your IPVM Membership on Jan 20, 2017
Here's how to get started and get the most out of your IPVM membership. Books for Members All members can download the 3 member-only books below...
Jim Cramer Sucks Up To Knightscope on Jan 19, 2017
Credit must be given to Knightscope. They are raising money right now and despite their $80 million pre-money valuation against a lowly sub $1...
ADT Launches Canopy - Professional Monitoring For DIY Devices on Jan 19, 2017
The intrusion industry has criticized DIY security systems for years, claiming systems like Canary or Scout cannot match professionally installed...
Dahua UnFavorability Results on Jan 19, 2017
Dahua, the mega-Chinese surveillance manufacturer not primarily owned by the Chinese government has been trying to break out of the shadow of...
Paxton Hosted Access - Disruptive Low Dealer Pricing on Jan 19, 2017
Paxton is entering the hosted access game, with BLU, at a cost that is a fraction of key competitors. The different approach could be very...
Geovision Launches Direct Cloud Offering on Jan 18, 2017
Add cloud, subtract integrator. Geovision has launched myGVcloud, an offering that allows consumers to buy cameras and cloud services directly...
Anixter / Bosch Sells Direct to Amazon on Jan 18, 2017
Anixter regularly says they do not sell direct to end users or that they do not do it anymore. However, over the past year, Anixter has sold Bosch...
Smart Power Tools For Security Installs on Jan 18, 2017
Installing a smart camera? Perhaps you should use a 'smart' drill. The intelligent appliance / IoT trend has hit power tools. In this note, we...

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