Detection, Classsification, Recognition and Identification (DCRI)

By: John Honovich, Published on Feb 04, 2013

Detection, classification, recognition and identification is all very easy until you put it in practice. Then you realize that there are big practical and subjective problems that make using them difficult.

Academically, the terms are straightforward and reflect what they mean in real English:

  • Detection - The ability to detect if there is some 'thing' vs nothing.
  • Recognition - The ability to recognize what type of thing it is (person, animal, car, etc.)
  • Identification - The ability to identify a specific individual from other people

Obviously, each level is harder and requires more detail, going from detection to recognition to identification.

Many manufacturers overview these categories including an Axis tutorial and a Bosch white paper [link no longer available]. For instance, here's the PPF chart that Bosch uses to provide concrete numbers:

And here is the Axis table:

Both relate a targeted PPF number to a certain level. While Bosch uses imperial and Axis uses metric units, the two manufacturers numbers are way off.

For identification:

  • Bosch recommends ~50ppf
  • Axis recommends ~80ppf
  • The Swedish National Lab recommends ~150ppf (cited inside the Axis paper)

Your first reaction might be, "What is going on here? Is someone wrong, lying or confused?"

Get Notified of Video Surveillance Breaking News
Get Notified of Video Surveillance Breaking News

Any of them might be the case individually, but, unfortunately, two fundamental issues exist with using these metrics.

2 Fundamental Issues

First, the terms are inherently subjective and depend on the perception and preferences of the individual viewer.

What is good enough for 'identification' can vary considerably among people. In our trainings and presentations, we have seen passionate debates break out about what passes for identification.

Try this for yourself. Look at the 3 images side by side below:

Which one, for you, is sufficient for identification? 40 (on the left), 60 (in the center) or 80 (on the right)?

In an IPVM class, it was a three way tie.

You face the same challenges in determining what's good enough for detection. Again take these image side by side:

What makes this particularly challenging is that seemingly modest changes in visual details captured can mean the difference of 2x the number of pixels per foot, which can have a massive impact on camera layouts and project design.

Warning

When people look at an image by themselves, the answer often appears 'obvious'. It is only when they confer with other people that it becomes a debate as they realize many others have different perceptions.

How do you resolve this scientifically? It is a tough call and ultimately the 'winner' is whoever is paying for the system.

Pixels and Image Quality

The other issue is that the same number of pixels will deliver different image quality depending on the time of day. You might be OK in perfect even lighting conditions with 50ppf for identification but if the sun sets or rises in line with the camera you might need more. Worse, if you only have street lighting at night, you still might need twice as many pixels per foot.

What to Do?

Using these terms and thinking about them as a goal is useful. Just do not treat this as simple math that is guaranteed to always work.

Most importantly, set the right expectations:

  • What level of details does the user/buyer/decision maker really want? Decide with a visual example, don't just say 'detection' and hope they agree when the system is commissioned.
  • What lighting or environmental issues are faced and how much of an impact will it have? Make this clear up front with the user/buyer/decision marker so they understand the inherent challenges in a real world operation.
Comments (16) : PRO Members only. Login. or Join.

Related Reports

Last Chance - Camera Course Winter 2020 on Jan 30, 2020
This is the only independent surveillance camera course, based on in-depth product and technology testing. Lots of manufacturer training exists...
2020 Camera Book Released on Jan 10, 2020
This is the best, most comprehensive security camera training in the world, based on our unprecedented testing. Now, all IPVM PRO Members can get...
Getting Started With Your IPVM Membership on Dec 02, 2019
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...
Security Sales Course January 2020 - Last Chance on Jan 02, 2020
Notice: This is the last chance to register for the course. This sales course is customized for the current needs and challenges specific to...
2020 IP Networking Book Released on Jan 06, 2020
The new IP Networking Book 2020 is a 280 page in-depth guide that teaches you how IT and telecom technologies impact modern security systems,...
Manufacturer Favorability Guide 2019 on Jun 12, 2019
The 259 page PDF guide may be downloaded inside by all IPVM members. It includes our manufacturer favorability rankings and individual...
Covert Facial Recognition Using Axis and Amazon By NYTimes on May 20, 2019
What if you took a 33MP Axis camera covering one of the busiest parks in the US and ran Amazon Facial Recognition against it? That is what the...
False Verkada 'Unrivaled' Low Light Performance Claim Removed on Jun 12, 2019
Verkada falsely claimed that it delivered 'UNRIVALED LOW LIGHT PERFORMANCE' until IPVM questioned. In fact, Verkada's low light performance is...
Video Surveillance 101 Course - Register Now on Feb 01, 2020
IPVM's first Video Surveillance 101 course starts this month, designed to help those new to the industry to quickly understand the most important...
IPVM Opens 12,000 Sqft Testing Facility on Dec 16, 2019
IPVM is proud to announce the opening of the world's first video surveillance testing facility that will allow us to significantly expand our...

Most Recent Industry Reports

Hanwha Wisenet X Plus PTRZ Tested on Feb 14, 2020
Hanwha has released their PTRZ camera, the Wisenet X Plus XNV-6081Z, claiming the "modular design allows for easy installation". We bought and...
PRC Warns Against China Video Surveillance Hacks, Hikvision Targeted on Feb 14, 2020
Hackers are targeting China video surveillance manufacturers and systems, according to the PRC's main cyber threat monitoring body. The hackers...
IPVM Conference 2020 on Feb 13, 2020
IPVM is excited to announce our 2020 conference. This is the first and only industry event that will be 100% sponsor-free. Like IPVM online, the...
Bosch Dropping Dahua on Feb 13, 2020
Bosch has confirmed to IPVM that it is in the process of dropping Dahua, over the next year, as both IP camera contract manufacturer and recorder...
BluB0X Alleges Lenel, S2, Software House Are Dinosaurs on Feb 13, 2020
BluB0X is running an ad campaign labeling Lenel, S2, Software House, Honeywell, AMAG and more as dinosaurs: In a follow-up email to IPVM,...
London Live Police Face Recognition Visited on Feb 13, 2020
London police have officially begun using live facial recognition in select areas of the UK capital, sparking significant controversy. IPVM...
Converged vs Dedicated Networks For Surveillance Tutorial on Feb 12, 2020
Use the existing network or deploy a new one? This is a critical choice in designing video surveillance systems. Though 'convergence' was a big...
Monitoreal "Completely Autonomous" Home AI Tested on Feb 12, 2020
Monitoreal claims to allow users to "see the things you want (people, vehicles, animals) and ignore the things you don’t”, using AI to distinguish...
Cisco Video Surveillance Is Dead, Long Live Cisco Meraki Video Surveillance on Feb 11, 2020
A dozen years ago much of the industry thought that Cisco was destined to dominate video surveillance. They stumbled repeatedly, failing. Now it is...
BICSI For IP Video Surveillance Guide on Feb 11, 2020
Spend enough time around networks and eventually someone will mention BICSI, the oft-referenced but only vaguely known standards body prevalent in...