UngarMax
Posts: 3
Joined: Thu Mar 26, 2020 4:52 pm

No-IR effect

Thu Mar 26, 2020 5:01 pm

Hi there,

I am planning to build a facial recognition system using a Raspberry Pi 3A+ and the official Raspberry Pi No-IR camera module. I've chosen the No-IR model instead of the standard model because the system I plan to build will have to work under low light conditions.

I reckon the system will have difficulties to recognize trained faces, and therefore I was thinking of applying an effect to the training images before using them to train the system, in order to simulate the same effect the No-IR camera produces. I think this will avoid issues in the facial recognition system, but I am not completely sure.

Have you ever developed such a recognition system using a No-IR camera? What considerations did you take?

Thanks in advance.

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HermannSW
Posts: 2006
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
Contact: Website Twitter YouTube

Re: No-IR effect

Fri Mar 27, 2020 9:51 am

I cannot answer whether it is good or bad to have no IR filter for face recognition.

All I can say is that colors look very different outside at daylight:
https://forum.arduino.cc/index.php?topi ... msg3268945

Robot Raspberry v1 NoIR camera view:
Image

Same location and time view with smartphone camera with IR filter:
Image
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/github_repo_i420toh264
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

UngarMax
Posts: 3
Joined: Thu Mar 26, 2020 4:52 pm

Re: No-IR effect

Fri Mar 27, 2020 12:24 pm

HermannSW wrote:
Fri Mar 27, 2020 9:51 am
I cannot answer whether it is good or bad to have no IR filter for face recognition.

All I can say is that colors look very different outside at daylight:
https://forum.arduino.cc/index.php?topi ... msg3268945

Robot Raspberry v1 NoIR camera view:
Image

Same location and time view with smartphone camera with IR filter:
Image
Do you know if it would be possible to apply a No IR filter effect to an image taken with a camera that has IR filter (using Python or similar)? How?

gordon77
Posts: 4626
Joined: Sun Aug 05, 2012 3:12 pm

Re: No-IR effect

Fri Mar 27, 2020 1:08 pm

Does your face recognition code work in colour or black and white?

UngarMax
Posts: 3
Joined: Thu Mar 26, 2020 4:52 pm

Re: No-IR effect

Fri Mar 27, 2020 1:17 pm

gordon77 wrote:
Fri Mar 27, 2020 1:08 pm
Does your face recognition code work in colour or black and white?
Nope, I haven’t code anything yet! I am just planning to build a facial recognition system capable of working with Raspberry PI’s No IR camera. It’s unclear for me whether it would be better to buy the standard camera (with IR filter) and lose the possibility of recognizing faces under low light conditions. I am asking whether it’s possible and which considerations do I have to take in mind.

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HermannSW
Posts: 2006
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
Contact: Website Twitter YouTube

Re: No-IR effect

Fri Mar 27, 2020 2:31 pm

UngarMax wrote:
Fri Mar 27, 2020 12:24 pm
Do you know if it would be possible to apply a No IR filter effect to an image taken with a camera that has IR filter (using Python or similar)? How?
No, because the infrared light has been filtered and is not captured.
and lose the possibility of recognizing faces under low light conditions.
You cheat, even a NoIR camera will get dark images at night if you do not use bright IR light.

Without IR light you need to use other cameras, eg Veye-mipi-327 camera, see low light image here:
https://www.raspberrypi.org/forums/view ... 4#p1614494
⇨https://stamm-wilbrandt.de/en/Raspberry_camera.html

https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/github_repo_i420toh264
https://github.com/Hermann-SW/fork-raspiraw
https://twitter.com/HermannSW

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: No-IR effect

Fri Mar 27, 2020 3:34 pm

UngarMax wrote:
Fri Mar 27, 2020 12:24 pm
Do you know if it would be possible to apply a No IR filter effect to an image taken with a camera that has IR filter (using Python or similar)? How?
It's not an effect. It's down to the fact that all 3 channels are equally sensitive to IR, and with sunlight having a significant IR content you get very strange colouring to the image.

And a NoIR camera will do nothing extra in low light over a normal sensor unless you add some additional IR illumination.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

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