X
Get all access to the world's best video surveillance information.
Logo
Free-book-promo-680-70

The Definitive Guide to PPF

by John Honovich, IPVM posted on Nov 04, 2012 About John Contact John

The most advanced yet most dangerous way to specify surveillance is pixels per foot (PPF, aka pixels per meter, PPM or pixel density). As much as it can help, it can make matters far worse, leading to overconfidence and poor performance.

PPF Established Metric

Yet PPF has become a critical established metric in the surveillance industry:

  • Broad camera manufacturer support: Most of the major vendors advocate the use of this metric.
  • Common A&E specifications: Architects and engineers who plan large projects regularly use PPF as the basis for their designs and surveillance plans.
  • Need for Something: With so many resolution options today, the old metrics for 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 50ppf. 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 are nearly never addressed:

  • 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
The complete report is available only to PRO Members.
Inside the Pro Section

Inside PRO Members may read our detailed analysis and explanation of how to best use PPF productively and take our 10 question PPF test at the end. Budget 30 minutes to read the full in-depth report.

Want to read the rest of The Definitive Guide to PPF and get immediate access?






Most Recent Industry Reports

Axis 4K Tested on Oct 29, 2014
Two years ago, Axis declared the megapixel race over. Now, they are among the first to release a 4K (8.3MP) camera. However, the question is simply: do we really need more pixels? We bought an Ax...

Top Manufacturers Gaining and Losing Ground on Oct 27, 2014
IPVM survey results of 100 integrators show what manufacturers are gaining and losing ground in 2014. Integrators answered 2 questions: "Added: This year, in 2014, what new product lines have you...

Getting Started With Your IPVM Membership on Oct 24, 2014
Here's how to get started and get the most out of your IPVM membership. Getting Started Video Presentation You can watch the 20 minute video immediately below or scan through the whole post for i...

Hikvision HDTVI Cameras Tested on Oct 22, 2014
HD Analog is the most interesting new trend in the industry now, claiming HD quality over legacy coax, with simpler configuration and lower prices than IP. IPVM has tested two of the ent...

Testing Arecont Omni on Oct 20, 2014
The Arecont SurroundVideo Omni is one of the most novel new camera offerings in the past few years. Like their 180 and 360 predecessors, the Omni supports 4 imagers / cameras inside. The major adv...

The Worst HD Quality Camera Ever (Samsung 1280H) on Oct 15, 2014
Samsung, what are you doing? Their new 1280H offering significantly stretches video and is one of the most bizarre offerings we have ever seen. Earlier this year, Samsung trumpeted that 1280H wou...

Winners Losers Fall 2014 on Oct 13, 2014
We are all losers, IPVM included. The historically poor new releases for Essen / ASIS make 2014 the worst year for surveillance innovation in, at least, a decade. (See our in depth manufacturer re...

Smart IR Panoramic Camera Tested on Oct 10, 2014
Panoramic cameras are overwhelmingly quite bad in low light. Now, manufacturers are starting to add IR to them. We tested the Hikvision panoramic IR earlier this year. Now, Vivotek has released t...

Testing Speco IP Intensifier on Oct 06, 2014
Chances are you have seen Speco's promotion of its Intensifier HD IP line, with ads online and in trade mags claiming color images down to an incredible 0.0005 lx. Speco funded a vacation f...

Testing IP Camera Latency on Sep 26, 2014
How much does latency impact IP cameras? We tested a number of combinations, like so: In this report, we break down: Average latency metrics in our test Key drivers of latency Variations i...