Pixels Determine Potential, Not Quality

By: John Honovich, Published on Oct 20, 2013

Pixels = resolution = quality is not always true, since other factors impact quality (low light, bright light, lens quality, etc.). 

However, pixels determine potential quality. In this note, we explain why you will make much clearer and better decisions recognizing this.

Demonstrating This With Images

Here's a relatively high quality, high 'resolution' image:

It's 161 pixels wide across a small area of 1 - 2 feet, delivering a high ~100 PPF.

Now contrast this with this low quality, low resolution image:

This is 5 pixels wide and a total of 35 pixels covering the same exact area as the image above (enlarged so you can see it). This is clearly low quality.

Why? The pixels are being forced to cover areas wider than the details desired. You can see it the blockiness of the image. Those blocks are the limits of the pixel.

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

The image calls out 3 of the 35 pixels but you can make out pretty much all the individual pixels.

Now let's increase the pixels / resolution for this image.

A lot more details are being revealed now, as the number of pixels increases from 35 total to 140 and each pixel now can cover a smaller area.

Let's compare the two images to see key details in the image improve:

In the former image, the eyes were bigger than the pixels and therefore could not be captured. However, in the latter one, with pixels cover an area smaller than an individual eye, allows the eyes to be captured as two black dots.

Let's increase the pixels for this scene, from 140 to 240:

As each pixel covers a smaller area, more features continue to emerge - lips, ears, etc. and the eyes become more detailed (eyebrows, iris, etc.).

Finally, here's 4 samples ranging from 35 to 2120 pixels covering the same area:

Clearly, as we increased pixels allocated, the more fine details that can be captured.

The smaller pixel count images, regardless of how 'good' the camera or encoder was could not capture those details because the pixels were covering too large an area for them. This is what we mean by pixels determine potential.

Pixels Limits on Quality

A 1MP camera will never capture the fine details of the face of a subject at a 50' wide FoV. It simply lacks the potential, because the pixels will cover too large an area relative (25ppf) to how small a face is at the same position.

However, a 5MP came covering that same 50' wide FoV may capture the fine details. It has the potential, because the pixels will be covering small enough areas (50ppf).

This potential, though, is a maximum theoretical limit bound by very important factors like:

  • Ability to capture in low light scenes (which most 5MP+ cameras are terrible at).
  • Ability to handle wide dynamic range scenes (see example).
  • Quality of lens, preciseness of focus and eliminating any DoF problems.
  • Minimizing compression artifacts / loss of quality (see tutorial).
  • Angle of incidence of subject to camera (if the camera is too high or the person is looking askew from the camera, more pixels will not help).

Quality vs Pixels

Ultimately, image quality is driven by a half dozen factors combined. While pixel density / count determines the potential quality and the maximum achievable details, those other factors, that are often overlooked and ignored in PPF calculations, routinely and often dramatically constrain the actual image quality achieved.

3 reports cite this report:

Selling 4K Cameras on Jun 21, 2016
This is a first in a new series to help integrators and manufacturers do a...
Resolution: 4K vs 2160p vs 8.3MP on Apr 24, 2015
4K, 2160p and 8.3MP all basically refer to the same 'thing', just different...
Axis 4K Tested (P1428E) on Oct 29, 2014
[UPDATE August 2015: We recently updated firmware on this camera for an...
Comments (6) : Members only. Login. or Join.

Related Reports

Video Surveillance Cameras 101 on Feb 25, 2020
Cameras come in many shapes, sizes and specifications. This 101 examines the...
Directory of 201 "Fever" Camera Suppliers on Aug 04, 2020
This directory provides a list of "Fever" scanning thermal camera providers...
IronYun AI Analytics Tested on Feb 17, 2020
Taiwan / US startup IronYun has raised tens of millions for its "mission to...
New Axis M30 Cameras Tested on Mar 26, 2020
Axis has released a new generation of, for them, relatively low cost M30...
Cheap Camera Problems at Night on Feb 19, 2020
Cheap cameras generally have problems at night, despite the common perception...
Sunell "Panda Cam" Thermal Body Temperature System Examined on Apr 09, 2020
Sunell's Panda Cam is the most visually recognizable coronavirus camera, sold...
Integrated IR Camera Shootout 2020 - Avigilon, Axis, Bosch, Dahua, Hanwha, Hikvision, Panasonic, Uniview, Vivotek on Jan 30, 2020
The best and worst cameras tested in this IPVM shootout showed major...
FLIR A Series Temperature Screening Cameras Tested on Jun 04, 2020
FLIR is one of the biggest names in thermal and one of the most conservative....
IR Surveillance Camera Guide on Feb 06, 2020
Integrated infrared (IR) cameras are everywhere in 2020, but not all IR is...
The Next Hot Fever Detection Trend - $100 Wall-Mounted Units on Jul 06, 2020
The first wave of the booming fever detecting market was $10,000+ cameras,...
Multi-Imagers Added to IPVM Camera Calculator on Jun 15, 2020
IPVM has added multi-imager cameras to the Camera Calculator, supporting this...
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...
Facial Recognition 101 on Mar 18, 2020
Facial recognition interest, use and fear is increasing. This guide aims to...
Sunell Panda Cam Body Temperature Measurement Camera Tested on May 14, 2020
Sunell is far less well known than its gargantuan domestic competitors Dahua...
FLIR Screen-EST Screening Software Tested on Jun 30, 2020
In our FLIR A Series Test, the cameras' biggest drawback was their lack of...

Recent Reports

Genetec CEO Declares "We Don't Negotiate Payment With Patent Trolls" on Aug 11, 2020
Are patent trolls like terrorists? Genetec's CEO is coming out strongly...
Hanwha AI Analytics Camera Tested on Aug 11, 2020
Hanwha has released their Wisenet P AI camera, adding person and vehicle...
Alabama Schools Million Dollar Hikvision Fever Camera Deal on Aug 11, 2020
The Baldwin County, Alabama public schools purchased a $1 million, 144-camera...
Dahua Taunts Australian Government, Continues To Sell Illegal Fever Cameras on Aug 10, 2020
Dahua is effectively taunting the Australian government by continuing to sell...
HID Releases VertX Replacement Aero on Aug 10, 2020
HID is replacing two established and broadly supported types of access...
NDAA Compliant Video Surveillance Whitelist on Aug 10, 2020
This report aggregates video surveillance products that manufacturers have...
Telpo China Temperature Tablets Tested on Aug 10, 2020
The provider for overseas companies ranging from Canon Singapore to US'...
Dangerous Hikvision Fever Camera Showcased by Chilean City on Aug 07, 2020
Deploying a fever camera outdoors, in the rain, with no black body, is...
"Grand Slam" For Pelco's PE Firm, A Risk For Motorola on Aug 07, 2020
The word "Pelco" and "grand slam" have not been said together for many years....
FLIR Stock Falls, Admits 'Decelerating' Demand For Temperature Screening on Aug 07, 2020
Is the boom going to bust for temperature screening? FLIR disappointed...
VSaaS Will Hurt Integrators on Aug 06, 2020
VSaaS will hurt integrators, there is no question about that. How much...
Dogs For Coronavirus Screening Examined on Aug 06, 2020
While thermal temperature screening is the surveillance industry's most...
ADT Slides Back, Disappointing Results, Poor Commercial Performance on Aug 06, 2020
While ADT had an incredible start to the week, driven by the Google...
AHJ / Authority Having Jurisdiction Tutorial on Aug 06, 2020
One of the most powerful yet often underappreciated characters in all...
SIA Coaches Sellers on NDAA 889B Blacklist Workarounds on Aug 05, 2020
Last month SIA demanded that NDAA 899B "must be delayed". Now that they have...