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. 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 Video Surveillance News In Your Inbox
Get Video Surveillance News In Your Inbox

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

Hikvision DeepinView Camera Analytics Tested on May 08, 2019
Hikvision is expanding its 'deep learning' offerings with a new camera series called 'DeepinView' claiming false alarm reduction and improved...
Subnetting for Video Surveillance on Apr 30, 2019
This guide explains when subnetting is used on security networks, and how it works. We explain how to add or remove IP addresses to your range,...
The HIVIDEO $31 Face Detection DVR Tested on Apr 25, 2019
Face detection in a $31 DVR? That is what "HIVIDEO" (not to be confused with Hikvision, even if the company intends to do that) was promoting at...
Door Operators Access Control Tutorial on Apr 17, 2019
Doors equipped with door operators, specialty devices that automate opening and closing, tend to be quite complex. The mechanisms needed to...
Dahua Repositionable IR Multi-Imager Camera Tested on Apr 16, 2019
Dahua has released their first repositionable multi-imager camera, the Multi-Flex 4x2MP, claiming integrated IR, true WDR, and flexible...
Pole Mount Camera Installation Guide on Apr 11, 2019
Poles are a popular but challenging choice for deploying surveillance cameras outdoors. Poles are indispensable for putting cameras at the right...
Axis 5MP P Vs Q Camera Shootout (P3227-LVE vs Q3517-LVE) on Apr 02, 2019
While Axis' Q3517-LVE tested well, it is one of Axis' most expensive dome cameras, over $1,000 USD. Because of this, members asked us how it...
UTC Interlogix Series 6 Tested on Mar 25, 2019
UTC Interlogix has long been deceptively OEMing Hikvision as our 2017 results show. Now, Interlogix is back with their newest IP camera series,...
Pelco GFC 4K Dome Camera Tested (IMP831-1ERS) on Mar 12, 2019
Pelco has finally released their first 4K IP camera, after years of competitors' releases. Is this move too late? Or is their new GFC Professional...
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...

Most Recent Industry Reports

NJ Law Requires Apprenticeship For Public Works Integrators on May 24, 2019
Few integrators do a formal apprenticeship program. However, now a NJ law is requiring any integrator on public works projects (such as state...
Security / Privacy Journalist Sam Pfeifle Interview on May 24, 2019
Sam Pfeifle is best known as the outspoken former Editor of Security Systems News. After that, he was publications director at the International...
Verkada Video Quality Problems Tested on May 23, 2019
Verkada suffers from numerous video quality problems, not found in commercial IP cameras, new IPVM testing of Verkada vs Axis and Hikvision...
Average Frame Rate Video Surveillance 2019 on May 23, 2019
What is the average frame rated used in video surveillance systems? In IPVM's 2011 statistics, the average was 6-8fps increasing to ~10fps in...
Access Control Job Walk Guide on May 22, 2019
Significant money can be saved and problems avoided with an access control job walk if you know what to look for and what to ask. By inviting...
ASCMA / Monitronics Declares Chapter 11 Bankruptcy Plan on May 22, 2019
Monitronics is entering into Chapter 11 bankruptcy. The company, also called Ascent Capital Group Inc., aka ASCMA, aka Brinks Home Security,...
US Considers Sanctions Against Hikvision and Dahua on May 22, 2019
The US government is considering blacklisting "up to 5" PRC surveillance firms, including Hikvision and Dahua, Bloomberg reported, with human...
Dahua USA Celebrates 5 Years of Errors on May 21, 2019
Dahua USA is, in their own words, 'celebrating' 5 years in North America or as trade magazine SSN declared: Dahua Technology finds success in...
Axis ~$150 Outdoor Camera Tested on May 21, 2019
Axis has released the latest in their Companion camera line, the outdoor Companion Dome Mini LE, a 1080p integrated IR model aiming to compete with...
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...

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