Beware Imager vs Stream Resolution

By: Ethan Ace, Published on Sep 10, 2015

Typically, a camera's sensor resolution and stream resolution are the same. So a camera with a 3MP imager supports a 3MP stream max.

However, sometimes the actual stream resolution supported is significantly less than the imager resolution. Worse, some manufacturers try to obscure this to make their cameras look higher resolution, causing confusion and disappointment for users.

Panoramic cameras are the most common example of this problem. In this note, we explain the differences and the risks involved.

*********, * ******'* ****** resolution *** ****** ********** are *** ****. ** a ****** **** * 3MP ****** ******** * 3MP ****** ***.

*******, ********* *** ****** stream ********** ********* ** significantly **** **** *** imager **********. *****, **** manufacturers *** ** ******* this ** **** ***** cameras **** ****** **********, causing ********* *** ************** for *****.

********* ******* *** *** most ****** ******* ** this *******. ** **** note, ** ******* *** differences *** *** ***** involved.

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

Imager ********** ** ********* **********

***** ******* ******* ******* round (** **********) ****** of ****, *** ****** image ******* *** ***********, ***** is *********** ***** ** the ***** ***** ******, ****** black. **** ** ********* on *** **** *** right, ***** *****, *** sometimes *** *** ****** as ****.

***** *** ***** ** view **** *** ***** the ****** ***** ** the ******, *** ********* PPF **** ** ********** based **** ** *** actual ***** ** *** FOV, *** *** *** resolution. [**** ***************'* *********** ************* ** ********** ***** of ****, ***** ***** more ** *** *********** imager, *** ***** ** still ***** ***** **** to *** ***** ** the ***.]

**** ************* **** *** camera's ***** ** * square ****** ***** ** eliminate *** ****** ***** space **** *****. *** example, * *** ****** (2592x1920) *** ** ******* to *********, ** ** the ***** *****:

Manufacturer ********

***** *** ******* ******** of ************* ********* ******* using ***** ****** **********, instead ** ********* **********:

*** ***** *** **** *** do ** *****, ** well.

**********, ******* ** ***** issues, *** ******* ** may ** ********* ** determine *** ********** * given ****** ** *********, best ******** ** ** test **** ****** ********* camera ** *****. ** this ** *** ********, those **** ******, ***-******** aspect ****** *** ********* more *********** **** ***** specifying *** **** ****** resolution. 

Comments (10)

Thank you Ethan for pointing this topic!

Question: are there panoramic cameras with, for example, 5MP sensor (quite typicall now), but with only 2MP stream (panoramic or de-warped soft PTZ)?

The Axis M3007 comes to mind. It uses a 5MP sensor, but aside from the fisheye overview stream (5MP) it outputs much lower resolutions. For example, the dual panorama and PTZ view areas are both 1920x1440 max resolution, about 2.7MP. There are other examples but that one I know off the top of my head.

The main argument for this is that these streams are removing unnecessary regions from the image (like the black around the spherical view) or looking at only a portion of it, and that's why they are lower resolution. But it is still often deceptive and can be difficult to calculate.

There are other examples...

Same deal noted here after the test of Panasonic panoramic, yes?

  • This size of the camera's sensor is 12 MP.
  • The fisheye lens forms an image circle of 9 MP.
  • The images in the test are 5 MP.

Camera from your example is fair - it is still delivering sensor pixel-2-pixel. And other streams really do not need full resolution.

Any ideas about cameras where original imager(s) is/are completely obscured? Scallop maybe?

I have a mix of the geovision FE and Vivotek FE cameras, and have verified the above statement. I battled this on install but gave up on it...so I have to wonder if these 5mp FE cams are only putting out 3mp, if you buy the 3mp fe, will the image be scaled again or will it be 3mp.

Heres a snapshot of Geovision software stating the actual size of 1920*1920, the camera is a vivotek being ran on the geovision platform.

Some manufacturers crop the camera's image to a square aspect ratio to eliminate the wasted black space seen above. For example, a 5MP camera (2592x1920) may be cropped to 1920x1920.

1920x1920 = 3.7MP

And even that number is deceiving, the effective pixels are actually more like 2.9MP.

Ethan, do any of these new panoramics have lens options that might change the image circle, and therefore the amount of wasted pixels? I think I have a Mobotix that does, but it's old.

Off-topic, but I have to ask, what is all the debris and downed signage in the middle of the street? Was there an accident or a wind storm?

The intersection where we were shooting is pretty infamous here. The road to the right leads to what was supposed to be a shopping center but it was never built. There are parking lots and much of the site is paved, but no buildings. The debris is the road closed sign which was already on the ground when we got there, and broken sandbags which were holding it. Fun fact: this was the only site I was ever asked to leave by the police. The site is private property but we were on the sidewalk which is public. He asked me to go anyway.

The site is private property but we were on the sidewalk which is public. He asked me to go anyway.

The trunk being open gives the impression you were ready to high tail it out of there if necessary. ;)

I think this may be one of the worst offenders, the Dahua "12MP" fisheye.

Not only is it marketed as 12MP, the spec sheet lists the resolution as 4000x3000. Effective pixels.

The other ones don't seem to actually state a bogus stream resolution as well.

I don't know how many it does use, but it's not possible to have a fisheye with a resolution as high as the sensor unless the sensor is round, or you are including dark pixels, right?

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 on Panoramic

Avigilon 32MP and 12MP H4 Multisensor Cameras Tested on Jun 11, 2019
Avigilon has released their H4 Multi-Sensor line of cameras claiming "broad scene coverage and high image detail" We bought and tested the...
Vivotek 20MP Multi-Imager Tested on May 30, 2019
Vivotek has released their latest repositionable multi-imager camera, the MA9321-EHTV, a 20 MP model claiming "Supreme Night Visibility", "Optimal...
Panasonic 32MP Multi Imager Camera Tested (WV-X8570N) on May 16, 2019
Panasonic has released their first multi imager models including the 32MP (4x4K) WV-X8570N, claiming "Extreme image quality for evidence capturing...
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,...
Axis Bad Marketing - Panoramic Commercial on Nov 23, 2018
Axis is bad at marketing. Recall last month - Axis: "No One Wants To Buy A Camera" and, more generally their 2018 production introductions. But...
Hikvision PanoVu Mini Tested (Multi-imager + PTZ For ~$500) on Aug 07, 2018
Hikvision has released their first PanoVu Mini multi imager, the PanoVu DS-2PT3326IZ-DE3, with four 1080p imagers, including a PTZ and integrated...
Panasonic 9MP Panoramic Fisheye Tested (WV-X4571L) on Aug 02, 2018
Panasonic has released their latest fisheye camera, the WV-X4571L, with 12MP sensor and 9MP resolution, claiming "extreme image quality" under...
Panoramic Fisheye Camera Shootout - Avigilon, Axis, Dahua, Hanwha, Hikvision, Oncam And Vivotek on Jun 27, 2018
IPVM tested Avigilon, Axis, Dahua, Hanwha, Hikvision, Oncam And Vivotek 12MP panoramic fisheye cameras head to head, as shown in the test setup...
Dahua 12MP Fisheye Camera Tested (NK8BR4) on May 16, 2018
Continuing our coverage of 12MP sensor fisheye cameras, we bought and tested the Dahua NK8BR4, examining: Default vs. Optimized...
Axis 12MP Stereographic Camera Tested (M3058-LVE) on May 10, 2018
Axis has released the M3058-PLVE, a 12MP sensor, stereographic panoramic camera and Axis' first with integrated IR claiming images "sharp to the...

Most Recent Industry Reports

How Cobalt Robotics May Disrupt Security on Sep 13, 2019
While security robots have largely become a joke over the last few years, one organization, Cobalt Robotics, has raised $50+ million from top US...
Panasonic 4K Camera Tested (WV-S2570L) on Sep 13, 2019
Panasonic has released their latest generation 4K dome, the WV-S2570L, claiming "Extreme image quality allows evidence to be captured even under...
ASIS GSX 2019 Show Report Final on Sep 12, 2019
IPVM went to Chicago for ASIS GSX 2019, with many exhibitors disappointed about traffic and the exhibitor schedule changing next year. Inside we...
Installation Course - Last Chance - Register Now on Sep 12, 2019
Last Chance - Register Now - September 2019 Video Surveillance Install Course. Thursday, September 12th is your last chance to register for the...
Commend ID5 Intercom Tested on Sep 12, 2019
Commend touts the new ID5 intercom as 'timelessly elegant' and the slim body, glass front touchscreen indeed looks better than common, but ugly,...
US State Department: "Chinese Tech Giants" "Tools of the Chinese Communist Party" on Sep 12, 2019
The US State Department has called out "Chinese tech giants" for being "tools of the Chinese Communist Party" in a blunt new speech that makes...
Uniview OEM Directory on Sep 11, 2019
This directory lists 20+ companies that OEM products from Uniview, with a graphic and links to company websites below. It does not cover all...
Yi Home Camera 3 AI Analytics Tested on Sep 10, 2019
Yi Technology is claiming "new AI features" in its $50 Home Camera 3 "eliminates 'false positives' caused by flying insects, small pets, or light...
Hanwha Announces 32MP Camera + AI Line on Sep 10, 2019
In the first rise in maximum megapixel resolution in 5 years, Hanwha has announced a 32MP / 8K camera directly competing with Avigilon's H4 30MP /...
Fingerprints for Access Control Guide on Sep 09, 2019
Users can lose badges, but they never misplace a finger, right? The most common biometric used in access are fingerprints, and it has become one...

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