The PPF / PPM Video Surveillance Guide

Author: IPVM Team, Published on Dec 23, 2016

Pixels per foot / Pixels per meter is the most fundamental and valuable, though imperfect, metric for specifying video surveillance image quality.

In a single number, this metric (e.g., 10ppf, 40ppf, 100ppf) conveys important information about what the projected quality that a camera can provide.

The image below, taken from our Camera Calculator, demonstrates examples of common pixel per foot (ppf) levels:

PPF Established Metric

PPF has become a critical established metric for several reasons:

  • Broad camera manufacturer support: Most major manufacturers use this metric.
  • Common A&E specifications: Architects and engineers who plan large projects regularly use PPF / PPM as the basis for their designs and surveillance plans.
  • Need for Something: With so many resolution options today (from 1MP to 12MP and beyond), the old metrics which used percentage of screen covered make no sense. PPF has filled this void.

The Goal of PPF

PPF is a single metric (e.g., 10, 50, 90, etc.) that when specified should deliver a specific level of quality. For example, the parking lot camera must deliver 50 PPF. Instead of guessing or just specifying more resolution, using this metric should enable selection of the ‘right’ resolution for the scene. The final image, following the PPF metric, will then deliver a predictable level of quality.

PPF Problems

Alas, PPF suffers from many problems that must be factored in:

  • Assumes even lighting and ignores the impact of bright sunlight
  • Assumes day time lighting and ignores the impact of night time / low light viewing
  • Disregards differences in lenses and compression
  • Disregards that image quality needs are subjective and debatable
  • Fails to specify related and critical metrics to complement PPF

Despite this, PPF does have value for estimation and planning. It just cannot be used blindly or simplistically. Inside the PRO Member’s section, we explain:

  • How to calculate PPF
  • How to recognize PPF limitations and make adjustments
  • How to best use PPF productively

****** *** **** / ****** *** ***** ** *** **** fundamental *** ********, ****** *********, ****** *** ********** ***** ************ image *******.

** * ****** ******, **** ****** (*.*., *****, *****, ******) conveys ********* *********** ***** **** *** ********* ******* **** * camera *** *******.

*** ***** *****, ***** **** ********* **********, ************ ******** ** ****** ***** *** **** (***) ******:

PPF *********** ******

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

  • ***** ****** ************ *******: **** ***** ************* *** **** ******.
  • ****** *&* **************: ********** *** ********* *** **** ***** ******** ********* *** PPF / *** ** *** ***** *** ***** ******* *** surveillance *****.
  • **** *** *********: **** ** **** ********** ******* ***** (**** *** ** 12MP *** ******), *** *** ******* ***** ************** ** ****** *********** ** *****. *** *** ****** **** ****.

The **** ** ***

*** ** * ****** ****** (*.*., **, **, **, ***.) that **** ********* ****** ******* * ******** ***** ** *******. For *******, *** ******* *** ****** **** ******* ** ***. Instead ** ******** ** **** ********** **** **********, ***** **** metric ****** ****** ********* ** *** ‘*****’ ********** *** *** scene. *** ***** *****, ********* *** *** ******, **** **** deliver * *********** ***** ** *******.

PPF ********

****, *** ******* **** **** ******** **** **** ** ******** in:

  • ******* **** ******** *** ******* *** ****** ** ****** ********
  • ******* *** **** ******** *** ******* *** ****** ** ***** time / *** ***** *******
  • ********** *********** ** ****** *** ***********
  • ********** **** ***** ******* ***** *** ********** *** *********
  • ***** ** ******* ******* *** ******** ******* ** ********** ***

******* ****, *** **** **** ***** *** ********** *** ********. It **** ****** ** **** ******* ** **************. ****** *** PRO ******’* *******, ** *******:

  • *** ** ********* ***
  • *** ** ********* *** *********** *** **** ***********
  • *** ** **** *** *** ************

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

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

**** ** ****:

  • *** ** *** **** *** **** *******. *** *** ******* yourself ** *** ***** * ****** ****** *** *** ***** to ********** ********* ** ******* ** ***** ******* ****** ********** and ******.
  • ********** *** *** *********** ** **** ** *** *** ***** mistakes.
  • *** *** ** * ******** ** *** * ***** ** potential *********** **** ****** *** ******** **** ********.
  • *** *** ****** ***** ********* ******* ****** **/*/*** ** ***** surveillance.
  • *********** *********** *** *** ****** ************.
  • ** *** ************ ** ******* ********* *** ***** ***** **** in **************. *******, ******* ********** *** *** ****** ********** (***, low ***** ***********, ***.)

PPF ** ***

****, ** *** *** ********** **** ******, *** ********* *** metric **********, ****** *** ***** (***), ** ****. *******, *** is ******** ****, **** ** **** ******* ************ ** *** metric ******.

*** *********, *** ***** ***** ***** **** ******** *** ****** for **********. **** **** ******* ****** ************** ******** ****** ************, ** ******** ** ******** / ***.

How ** ********* ***** *******

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

  • *** ****** ** ********** ****** ** * ***** ****/******
  • *** ***** ** *** *** ** *** ****** ** *** point ** ********

Horizontal ***** *****

** ******* ** ******** ******** *** ********** ***** ***** *** do *** ******* ** **** *** ******** *** *** ******* resolution. *** ********, * **** ****** *** * ***** ********** of *** (*********** *.***) *** *** ********** ***** ***** ** 1280 *** *** ******** ***** ***** ** ***, **** ******** described ** **** * ***. ** ** *** ***** ****** in **** ****, *** ****, **** ****** *** ********* ***.

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

**** **** ** ******** **** ** **** *** ***** ***********.

Selecting *** *****

*** ****** **** ** *** *********** ** *** **** * Field ** **** *** ***** ** *****. *** ***** ***** shows * ****** ******** *** ********* *** ***, ****** ******* across ** *** ***** ** ********, **** *** **** *****:

*********** *** ***** ** *** *** *** ** ******** *** larger, **** *****, **** ** ******* **** ** ******. *** instance, *** ********* ***** ***** *** ********* *** ****** *** covering * ******* ***/*****.

**** ** ***** **** *** ** '*****', *** ** ******* on ******** *******.

  • ** ***** ******* ***** *** ****?** ******* ****** ** ******* ** *** ***** ** **** one, ****** ** *** **** ** *** ****** *****, ** may ** ****** ** *** *** ******** ***' *** *** calculations. ** ***** ** ** ***** ********, *** ***' *** need ** ** ****.
  • **** ********** *********** *** *****?** ****** ********* ** ******* ** ***********, ** **** **** this ** **** **** ********* ****. **** *** ** *** if ***** *** ***** ****** *** ********, ***** *** ********* limited ** *****. *** ** ** ** **** ******* *** be ****, ***** **** *** ********.

** ***** ** *** ***********, ** ********* ***** ***** ****, so **** *** ** *** ************* **** ***.

PPF *******

**** *** **** ********** *** ********** ****** ** *** ****** chosen *** ******** **** *** *****, *** ** ****** ********.

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

  • *** *** ***** * **** ****** ** ***** * ** foot **** ********: *** = *** ******* ********** ***** ***** is **** *** *** ***** = ** (*.*., **** / 10).
  • *** **** * *** ****** ******** * *** **** **** parking ***: *** = ~** ******* ********** ***** ***** ** 2592 *** *** ***** = *** (*.*., **** / ***).
  • * ***** ****** ** ********** * ** **** **** ******* entrance: *** = ** ******* ********** ***** ***** ** **** and *** ***** = ** (*.*., **** / **).

PPF ********* ** *** ***** *** ******** **** ****** *********

******* ** *** **** * '******' ***. **** *** *** is ******* ** *** *** *** ******* ** ******** ** from *** ******. *** ********, ***** ******* ****** **********, ** *** ***** **** * ******'* ***, ***** ***** PPF ** **** *****. ** *** *** **** *** ********* as ** ******** *** ****** ** ** ***, *** ******* the ****** ** ******* *********, ** ***, ***, ** *** PPF.

******* *********, *** *** ***** ********* ** ** ***** *** FOV, **** *****. ******** *** ****** ** *** *** *****, we *** *** *** ********, *********** ** ***.

*** *** *** **** *** ******** ** ******* ****** **********.

Fisheye ***** ** **** ******

*******, ****** ** ***** ** **** ***** **** ***** ******* panoramic ******, ** *** ***** ************, **** ****** **** ******** cameras.

***** *** (*) *** ******* ** ** *******, *** * fisheye ********* (*** ****) *** *** ***** ***** * ~**° HFoV. ******* *** **** ** *** ** ******** ** **** away **** **** ******:

  • **** * *** *********, ** ** **** **** **** *** camera, *** *** ** ~**
  • **** * *** '************' **° ****, ** ** **** **** from *** ******, *** *** ** ~***

**** ** * ******* ********* **********. ***** *** ********* *** see ** '***' **********, ** *** *********, ** ** **** away, ****** **** **** **** ***** (**** **** ********). ** contrast, *** '************' **** **** ******* **** ******** ******* ****** though ****** * **** ******** ****.

*** *** **************** ********* ****** *********** **** *******.

Recognizing *** ***********

**** ***** *********** ***, ***** *** ******* ****** ***** ****** the ********* ******* ** ****** *********. *****, ** ******:

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

Wide ******* ***** ***********

*** ******* *** ****** *** *** **** *** *** ********* power *** **** *************. *** ******* ** ****** ****** ********* / ******** ** * *** *******. ** *** ***** *****, both ******* **** *** **** **********, ***** *** **** *** and *** ***** ** *** **** ****:

*******, *** ***** ** *** ***** ***** **** ** *** twice *** *** ***** ** *** *****. ****** *** *** is *** ****, *** ****** ** *** ***** *** *** stronger *** **** ********* ***.

**** ** ** ***** **** ** ****** **** **** ******** variations ** ***** ******. ** *** ***** *****, **** * has * ***** *** **** **** * *** **** * clearly ******** **** ***** ****** ******* **** * ** ** a ****** **** **** *** ****** ********* ** ****** ***********.

*** ****** ******** ******* **** *********** ** **** ******* ***** *** ***** *******.

Low ***** ***********

**** ** **** ********** *** *****, ** **** ** ****,****** ********* **** ****************, **** ******* ***** ******** ***** *******. **** *** ** seen ** *** ****** ** ****** *****, ******* *** ******* in *** **** **** **** *** ****** ** ******* ***** from *** ** *****, **** ***** ****** ******** ** ~*,***** on *** ****, *** ***** *** ** *** *****.

******* *** ***** *** ***** '****' ** ******* *********, **** the **** ******* ******* ***** ******* *** ******* **** ***** than ****** *** ***. *******, ************ *** ********** ****** ***** make **** ******** ********** *****.

** *** ****** **********, ** ******* ******* ***** ** **** world *** *** ***** ****** ** **** **** **********, **** PPF ********* ** **** **** ** ***** ****** ***** *******' parameters.

Differences ** ***********

******* *** ********* ******* **** *** ** *********** ***** ********. Even ** *** **** ********** *** *** **** ***** *** used, *** ****** ** *********** *** **** *******. ***** ************ that:

** ***** **** ***** *'* *** ** *** ***** **** image *, *** **** ** *** *** ****. *** *** less *** **** ***** * *** **** ** *** *** case. **** ****** *** ***** **** *** **** ******, **** the **** ********** ***** ********* *********** ** ***** *.

****** ** *** ********* *********, ************* *** **** ********* ******* compression ********, ** **** ** ********* *********** *** ***** ******* quality ******. ******* ****** *** ***** ****** ************ *********** ************* ******* ** ***** ******** *** ************ *****.

***** ****** ** ******* ** ***** *********** ****** ********** ************* ********* ** ***** ***** ******** ******. *** ******** ******* / *********** *********** **** ******* ** *********** *** *** *******.

Lens ***********

**** ***** **** **** ******* *** **** * **** ********** in ***** *******, ********** ** *** ****** ********. *******, ** our *****, **** ******* ** ****** * ***** *******, ******* fine ******* *********** ***** *** *********** ** **** ******. ***** factors, **** ***-****,******, *** ********** ************ *** *** **** ****** ** ****** image *******.

Subjective ***** *******

******* *** **** ********** ******* ** *** ** *** ********** the '*****' ******* ***** *** **. **** ** '****** ** in *** *** ** *** ********', *** ********** ****** *** think * ***** ******* ***** ** **** ****** ** '********' a *******, *** ******* *** ******* ************* **** ****** ** target *** ********.

*** *******: * ******** ***** ** ****** * ***** *******. Which ** *** ***** *** ****** ***** ** *****?

***** **** ** **** **** ****** ******* *** *** ** them **** ** ***** ** *******, **** ***** ****** *** 18 ** ** *** ******, ** **** **** **** **** just * ****** '****', **** **** **** ***** *******.

*** **** ********* ******** ****** **** ******** ******* *** **** pixels *** ****** ** ******** * ******** ******. ******* *** images *****:

**** ****** **** *** *** ~** *** ** *** **** is *** ***** *** **** **** **** * '*******' *****. Others **** **** ** **** ******, ********** ** *** ****** is *****, **** ** ** ******** ** ********.

********** ** **** ** '******' ****** ** ******, *** ***** to ****** **** *** ***** / ******** ***** **** **** think ** **********.

Related / ******** *******

**** ********** *******, *** ***** **** *** ******* ****** *********** to ******** ****** *******, ******* ** ********* ** *********. **** using ***, ******* ******* **** ** ****:

  • ***** ** **** *****: ***** ************** **** ** ****** *** *** *** *** needs ** **, ********* **** * *** ******. **** *** create ********* ** **** **** *** ******** ** ***** **** than ******. *******, ************ ***** *** ****, *.*., ** *** at ** ****, ***.
  • ******** ** ******: ******* *** *** *** ****** ***** ** ******* *** given *** ******* **** ********* ** **** ** *** ***** of *** ***. ********, *** ******* **** **** *** ****** one ****, *** ***** *** ***.
  • ***** ** *********: *******, ********** ** *** ****** ** ******, ** *** camera ****** *** ******* ********** ** ************, *** **** **** key ******* **** ***** ** ******* ***** **********. ** ********* ****** ** ***** ***********, ** ********** **** **° ** **** ** ***** *** proper ****** ******.

FOV **** **********

******* ** ********* ** ********** ***** ********* ******* **** **********, PPF ********* *** ****** ****** *** ******* *****. *** *******, in ***** **' **** ** ****, * ***** ****** **** provide ~******, **** **** ****** ****** *** * **** ******* day **** *****. ** ********, ** *** **** ***** ** SD ******, ** *** *** **** ***, *** ***** **** to ***** **** *** ***** ** * **** **** - a **% ********.

** *** ****** **** ****, *** **** ********* ****** *** performance ********* **** ** *** ******'* *** ***** *** *** performance. ********, ***** ******* **** ***** ******* **** ****** ******** and *** ***** *** *** **** ****** ** ****** ******** a '****** *** *****'.

Larger **** **** *********

*******, ***** **-** **** **** ****, *** ********* ******* **** trickier. ****** ** **** ***** ** * *** ****** **** increases *** ********** ***** ***** ********, ~**%. ******* ***********, ********* low ***** *** *** *********** ** *** ******* *** ***** than ***** ****.

** ******* ***** ********** *** *** ***** ***** ** ** can ****** ******** ** *** ***. *** ********, ***'* *** you **** ***** ****** * *** **** **** ****. ** do **, *** **** **** **** ********** ******. * ****** 14MP ****** *********** **** (** ** *** ~**** ********** ******) as ***** (*) *** *******. *** **** ******** ***** ***** be (*) ***** *******. ***** *** ***** *** ** ******** less (****), *** ******* ******* *** ** ******** ** ***, low *****, ***** ****, ***** ******* *******, ***.

PPF ********** ******* ** *************

**** *** **** ** ****, *** ****** ******* ** ************ PPF **********.********:***** ******* ****** ******, **** ******** *** ** *** ****** in *** ****** ** ****** ******** ** **** ****** ********, which ** ****** ************.

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

  • **** ******* / *********** ****** *** ******* ******:************* ******* ******* ** *** *** ***. **** ** ***** conditions, ** ** ******** ** ******* ***** *********** *******, ********** of ******* ******. ** ********, *** ** ****** ******** ****** lighting ** **** **** ** **** **** ******* **** ** visible, **** ** *** ****** ******* ** ********.
  • ******** ******* / ****** *** **** ** ****** (******, ***) is ***** *** *** *** *********** *******:************* ********* ********* ******* ** *** ** ***. **** ** fairly ********* ** **** ** ******** ** *****.
  • *** ******* / ********* ****:************* ******* * - ** ***. ** *******, ******* ** this *****, ** *** ** **** **** ** **** ******* out ****** *** ******* **** **** **** *** ***** ** if *** *** ******* *********. ** ******, **** **** ******** ideal ********. *** ** ***, ** *** **** **** **** 10 ***, *** *** ****** ****** ** **** *******. *******, some ********* ******* **** * *** *** ** ********, ** may ***** ** ****.

[****: **** ***** *** ********** ******* ** **** *** *** revised ** ****/**** ** ******** ******* ******* *** ******* ****** examples **** *** **** ****** **********.]

Comments (11)

However, in our tests, lens quality is rarely a major concern, despite fine quality differences which are perceptible in some lenses...

Has there been a specific test of lenses and their effect on apparent PPF? Some tests have indicated that in certain cases there might be substantial differences, A Major Flaw in Long Lenses and PTZs Found.

Plus with imager pixel density increasing, lenses are needed to have higher MTF.

You raise a good point. We'll add more info about long lenses and clarify.

Great article.

Note, we use PPF throughout this report, but sometimes the metric equivalent, Pixels Per Meter (PPM), is used. However, PPF is commonly used, even in many regions standardized on the metric system.

This bias for anything non-metric forever bemuses me.

Setting aside your 'regional' comment for just a moment, there are only 3 countries in the world not using the metric system. And with no offense to Burma or Liberia, it's the USA that you are acquiescing to here. So I ask you (IPVM) to reflect on PPF versus PPM. As 'the world's leading video surveillance information source, IPVM provides the best reporting, testing and training for 10,000+ members globally' [my emphasis on the areas in bold], who are you serving? What is the more exact measurement tool?

You say, 'PPF is commonly used, even in many regions standardized on the metric system. I wonder what you base that comment on? More importantly, if that is true, could the reason be because PPF is what we are force fed?

The US National Institute of Standards and Technology (NIST) has a very interesting paper on the subject of metric systems in the USA at https://www.nist.gov/sites/default/files/documents/pml/wmd/metric/1136a.pdf

Thanks for your consideration and Happy New Year.

James,

Our calculator has long supported metric and actually checks the country for each visitor defaulting to metric for those countries who use metric.

We will add in references to PPM values as well as PPF for all pictures / graphics after the New Year's and update the post.

James, all, we added PPM measurements to the images inside the report. Thanks.

Can anyone explain why the Horizontal Pixel count of 2592, for 5MP resolution, is less than the figure of 2688, for 4MP resolution?

This question is in reference to the table on page for of this tutorial.

Eddie, good eye.

The reason that 5MP has a lower horizontal pixel count than a 4MP camera is the difference in aspect ratios, i.e., 5MP cameras are 'taller' than 4MP ones:

5MP - 2592 x 1944

4MP - 2688 x 1520

Related - Aspect Ratio 16:9 vs 4:3 Shootout

Also, 3MP cameras have slightly greater vertical pixel count but much narrower horizontal one, i.e., 3MP - 2048 x 1536

Give a better idea of ppm.

I want to help, but I don't understand the question. Can you expand?

Clear explanation of changes in HFoV and change of PPF according to difference parameter. Great information.

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

Outdoor Camera Mounting Hardware Guide on Feb 21, 2019
Mounting cameras outdoors can be challenging, requiring understanding different types of equipment and methods. In this guide, we teach this...
Security Installation Tools Guide - 22 Tools Listed on Feb 19, 2019
In this guide, we cover 22 tools that security installers frequently use. This is one part of our upcoming Video Surveillance...
Axis IR Multi Imager Camera Tested (P3717-PLE) on Feb 18, 2019
Axis has released their first IR multi imager, the P3717-PLE, a repositionable model listing 360° IR illumination and flexible positioning,...
Hanwha Smaller Multi Imager Tested (PNM-9000VQ) on Feb 14, 2019
Hanwha's first repositionable multi imager PNM-9081VQ tested well, but was huge, over 12" wide and weighing in at over 10 pounds. Now, they have...
Bandwidth vs Low Light Shootout - Avigilon, Axis, Bosch, Dahua, Geovision, Hanwha, Hikvision, Uniview, Vivotek on Feb 08, 2019
Nighttime bandwidth spikes are a major concern in video surveillance, but do all manufacturers' cameras perform the same? Are some more consistent...
Sony Favorability Results 2019 on Feb 06, 2019
Sony Favorability amongst integrators improved moderately compared to their 2017 favorability results, with a modest net positive...
8MP HD Analog Tested (Dahua / Hikvision) on Jan 30, 2019
HD analog has promised higher resolution for years, but has lagged substantially behind for years. Now, both Dahua and Hikvision have started...
Designing Access Control Guide on Jan 30, 2019
Designing an access control solution requires decisions on 8 fundamental questions. This in-depth guide helps you understand the options and...
ONVIF Video Surveillance Tutorial on Jan 29, 2019
ONVIF is well known within the surveillance industry as an interface to connect IP cameras and VMS systems. However, new users may find it...
Access Control Turnstiles Guide on Jan 28, 2019
Turnstiles control pedestrian access to secured areas, essentially becoming moving portions of fences, walls, or barricades for physically stop...

Most Recent Industry Reports

Outdoor Camera Mounting Hardware Guide on Feb 21, 2019
Mounting cameras outdoors can be challenging, requiring understanding different types of equipment and methods. In this guide, we teach this...
HID Favorability Results 2019 on Feb 21, 2019
HID favorability results were strong, in the 2019 IPVM integrator study of 200+ integrators, with a net +62% and low negativity as the table below...
First US State, Vermont, Bans Dahua and Hikvision on Feb 21, 2019
The first US state, Vermont, has issued a ban on a number of Chinese and Russian manufacturers including the world's 2 largest video surveillance...
ADI 'SAVE BIG' On FLIR And Hikvision Examined on Feb 20, 2019
One is a major US defense supplier. The other is owned by the Chinese government. But you can "SAVE BIG" on both at ADI. In this note, we...
BluB0x Company Profile on Feb 20, 2019
BluB0x has doubled in revenue every year since its founding in 2013, according to CEO Patrick Barry. We originally reported on them in 2015. At the...
Security Installation Tools Guide - 22 Tools Listed on Feb 19, 2019
In this guide, we cover 22 tools that security installers frequently use. This is one part of our upcoming Video Surveillance...
Sales Cuts At Rasilient on Feb 19, 2019
Over the past 2 years, video surveillance storage specialist Rasilient has expanded its workforce significantly, aiming to build its own branded...
Exacq Raises VMS Software Pricing Twice in Less Than a Year on Feb 18, 2019
Most VMSes regularly release new features, but rarely increase their prices. For the 3rd time in 4 years, and 2nd time in 8 months, since being...
Axis IR Multi Imager Camera Tested (P3717-PLE) on Feb 18, 2019
Axis has released their first IR multi imager, the P3717-PLE, a repositionable model listing 360° IR illumination and flexible positioning,...

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