How Accurate Are Resolution Specs For Panoramic Cameras?

I just installed a DS-2CD6362F-I this past week and noticed the "6MP" claim to be a bit misleading... the full image is 2048x2048 (4MP) and there are three "digital PTZ windows" that can be up to (but not larger than) XGA (1024x768, or about 0.75MP)... it seems 6MP refers to the combination of all three.

Is this common of other panoramic cameras?

I was just reminded of the "Panoramic camera shootout" article, and looked through that, as well as a linked test of this camera and its 3MP little brother, but I didn't see any mention of this... discrepancy.

[IPVM Note: Covered: Beware Imager vs Stream Resolution]

Yup - they all seem to add up the horizontal pix and advertise that number. I suppose that makes reasonable marketing sense, and If the sensors are fixed, it makes more sense. However, the new Avigilon 3 sensor and 4 sensor panoramic cameras have independent cameras within the dome, with certain physical aiming restrictions. With each being a 3MP camera, they rightly call refer to them as a "multi-sensor" camera.

The part numbers are a little confusing - to me, MH means Multi-Head so maybe MH should be MS, but they didn't consult me.

9W-H3-3MH-DC1 3 x Image Sensor In-Ceiling HD Multisensor Dome Camera

12W-H3-4MH-DC1 4 x Image Sensor In-Ceiling HD Multisensor Dome Camera

Matt, you should be able to get a single 6MP stream out of that camera by using Mode 2*

*Whatever the hell that is ;)

"Whatever the hell that is"... or more importantly, however the hell you access it.

So it may actually be a 6MP, 3:2 sensor... but in the main image settings page, 2048x2048 is the highest option available (without going to Mode 2??).

It does actually output a 2048x2048 stream, vignetted areas notwithstanding...

B&H also lists it as 2048x2048 Max resolution.

Weird. This review showed this picture:

Which can best be described as warped and stretched.

So maybe you need to use Hik's stretching software. ;)

Ethan did a review but right before he selects the resolution drop down he changes the camera to camera 5.

Hmmm mine only listed up to "IP Camera 4". The 2-4 are the cropped 1024x768 "PTZ" views.

It's that damn mode 2 switch...

Seriously, is the firmware new?

Samsung seems to be marketing their fisheyes properly. The SNF-8010 has a 6MP sensor but is marketed as a 5MP camera.

Matt, have you tried setting real-time mode:

its supposed to only output one high-res stream then.

Ahhh I think I recall seeing that setting but didn't delve into it. I'll give that a try, thanks!

Thinking about it though, even if you get it to give you a 3072x2048 stream, I don't see how it could have any more actual information than a 2048x2048 one.

Barring an elliptical lens or non-square pixels, the image circle is just that, a circle, which will be inscribed in a square. A circle inscribed in a square takes up pi/4 of the area, or around 80%.

So if you get a 3072x2048 stream I would think one of the following three things is happening:

  1. Stretching the 2048 to 3072 in the horizontal.
  2. Asymmetric letter boxing.
  3. Image circle cut off on the top or bottom.

Net/net, a 4.2MP (2048x2048) stream, will contain the entire 3.3MP (80% of 4.2) image circle.

Anything else is BS or worse.

I could be very wrong of course, what do you think?

You're only slightly wrong. A circular crop of a 2048x2048 image (assuming the circle itself is a full 1024 pixel radius) would be 3.2941986583305710348142047482657 MP. :)

Ok, I stand corrected, but lets just leave it at 3.294198 MP, I would hate to give the impression that the sensor supported sub-pixel resolutions.

A reasonable compromise for unreasonable times!