Beware Imager vs Stream Resolution

Author: 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.

*********, * ******'* ****** ********** *** ****** ********** *** *** same. ** * ****** **** * *** ****** ******** * 3MP ****** ***.

*******, ********* *** ****** ****** ********** ********* ** ************* **** than *** ****** **********. *****, **** ************* *** ** ******* this ** **** ***** ******* **** ****** **********, ******* ********* and ************** *** *****.

********* ******* *** *** **** ****** ******* ** **** *******. In **** ****, ** ******* *** *********** *** *** ***** involved.

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

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

***** ******* ******* ******* ***** (** **********) ****** ** ****, but ****** ***** ******* *** ***********, ***** ** *********** ***** ** the ***** ***** ******, ****** *****. **** ** ********* ** *** left *** *****, ***** *****, *** ********* *** *** ****** as ****.

***** *** ***** ** **** **** *** ***** *** ****** width ** *** ******, *** ********* *** **** ** ********** based **** ** *** ****** ***** ** *** ***, *** the *** **********. [**** ***************'* *********** ************* ** ********** ***** ** ****, ***** ***** **** ** the *********** ******, *** ***** ** ***** ***** ***** **** to *** ***** ** *** ***.]

**** ************* **** *** ******'* ***** ** * ****** ****** ratio ** ********* *** ****** ***** ***** **** *****. *** example, * *** ****** (*********) *** ** ******* ** *********, as ** *** ***** *****:

Manufacturer ********

***** *** ******* ******** ** ************* ********* ******* ***** ***** sensor **********, ******* ** ********* **********:

*** ***** *** **** *** ** ** *****, ** ****.

**********, ******* ** ***** ******, *** ******* ** *** ** difficult ** ********* *** ********** * ***** ****** ** *********, best ******** ** ** **** **** ****** ********* ****** ** place. ** **** ** *** ********, ***** **** ******, ***-******** aspect ****** *** ********* **** *********** **** ***** ********** *** full ****** **********. 

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

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...
Vivotek 12MP Fisheye Camera Tested (FE9391-EV) on May 08, 2018
Next in our 12MP fisheye camera evaluation, we bought and tested Vivotek's latest generation FE9391-EV, a new model claiming improved smart IR...
Avigilon 12MP Fisheye Camera Tested on May 03, 2018
12MP fisheye cameras have become mainstream, with nearly every major manufacturer offering their take on this segment. To see how these new higher...
Best and Worst ISC West 2018 on Apr 16, 2018
ISC West 2018 had strong attendance, modest overall new products, and a surge in Artificial Intelligence marketing. First, here are 20+...
Axis Launches First Stereographic Panoramic Camera on Apr 05, 2018
Fisheye panoramics have not had much innovation in the past few years, with their multi-imager cousins getting most of the advances, e.g.,...
Camera Form Factor Guide on Mar 16, 2018
When selecting surveillance cameras, users may choose from a number of different form factors, each with its own unique strengths and weaknesses,...

Most Recent Industry Reports

'Sticker' Surveillance Camera Developed (CSEM Witness) on Nov 16, 2018
The Swiss Center for Electronics and Microtechnology (CSEM) has announced what it calls the: world’s first fully autonomous camera that can be...
ISC East 2018 Mini-Show Final Report on Nov 16, 2018
This is our second (updated) and final show report from ISC East. ISC East, by its own admission, is not a national or international show, billed...
Facial Detection Tested on Nov 16, 2018
Facial detection and recognition are increasingly offered by video surveillance manufacturers. Facial detection detects faces in an image/video...
Throughtek P2P/Cloud Solution Profile on Nov 15, 2018
Many IoT manufacturers either do not have the capabilities or the interest to develop their own cloud management software for their devices....
ASIS Offering Custom Research For Manufacturers on Nov 15, 2018
Manufacturers often want to know what industry people think about trends and, in particular, the segments and product they offer.  ASIS and its...
Hikvision Silent on "Bad Architectural Practices" Cybersecurity Report on Nov 14, 2018
A 'significant vulnerability was found in Hikvision cameras' by VDOO, a startup cybersecurity specialist. Hikvision has fixed the specific...
French Government Threatens School with $1.7M Fine For “Excessive Video Surveillance” on Nov 14, 2018
The French government has notified a high-profile Paris coding academy that it risks a fine of up to 1.5 million euros (about $1.7m) if it...
Integrator Credit Card Alternative Divvy on Nov 13, 2018
Most security integrators are small businesses but large enough that they have various employees that need to be able to expense various charges as...
Directory of Video Intercoms on Nov 13, 2018
Video Intercoms, also known as Video Door-Phones or Video Entry Systems, have been growing in the past decade as more and more IP camera...
Beware Amazon Go Store Hype (Tested) on Nov 13, 2018
IPVM's trip to and testing of Amazon Go's San Francisco store shows a number of significant operational and economic issues that undermine 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