Detect a candle fire using OpenMV H7 and FLIR

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mike58smile
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Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Sun May 26, 2019 8:49 am

Hello, my project is to use OpenMV cam H7 and some of the FLIR lepton to detect a candle fire (approximately 2 or less centimetres high) from at least 2 metre distance. I would like to know if it is possible (I also want the maximum FPS because it would be mounted to a moving object), then which FLIR Lepton to use to get the best results. I also tried doing it without FLIR, after using gamma correction and turning off automatic light correction I get almost good results, but it wasn't resistant to sun light (which I need it to be), but using grayscale I got 70 FPS witch was pretty great. So I would like to know what is the best way to use. Maybe also use the special sun lens you are offering.
Thank you a lot.
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iabdalkader
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby iabdalkader » Sun May 26, 2019 9:18 am

You can definitely use FLIR for this, but note it's limited to 9FPS.
mike58smile
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Sun May 26, 2019 9:48 am

Thank you! Do you mean FLIR Lepton 3 or 3.5? And do you think it can be done without it and somehow isolate the sun light using polarizing filter you are offering?
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kwagyeman
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby kwagyeman » Sun May 26, 2019 12:15 pm

Hi, the FLIR Lepton sees heat. As long as the sun isn't behind the candle it will isolate the sun out. You don't need the lens polarizer. That's for visible light. Not thermal.

I'd use the 3.5 if possible, you can set a target temperature rang using it.
Nyamekye,
mike58smile
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Sun May 26, 2019 12:27 pm

But maybe it would be not so good because of FPS, so I am mapping the possibillities. Do you think that without flir, with normal lens and the polarizar it can isolate sun and setect just the candle fire? Because then, it would have a lot more FPS, wouldn't it?
Btw thank you for your answers :D
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kwagyeman
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby kwagyeman » Sun May 26, 2019 2:56 pm

The polarizer works great when the light from the sun is reflected off a surface at some angle. It doesn't work looking right at the sun. You'd need to specify exactly how your system is setup. If you just need to remove reflected light from the sun the polarizer will work. Otherwise it will not.
Nyamekye,
mike58smile
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Sun May 26, 2019 3:47 pm

I don't need to look right at the sun, I just want to ignore the reflected sunlight going from window which is right above the field with the candles. The sun light is ussually seen as light stripes on the field.
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kwagyeman
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby kwagyeman » Sun May 26, 2019 6:42 pm

Okay, the polarizer may help them. I can't really offer any guarantees. It does work magic when it works however.
Nyamekye,
mike58smile
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Wed May 29, 2019 1:15 pm

Can I somehow set the maximum detecting value (I know, you can set the minimum - that is pixel and area treshold) so it can ignore the bright areas with bigger area and detect just the object that has small area...? I hope you understanded it
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kwagyeman
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby kwagyeman » Wed May 29, 2019 1:45 pm

Hi, use the filter method in Python and filter out blobs returned that pass the maximum value you want to ignore. Find blobs returns a list of values. So, just inspect the pixel/area count per blob returned and ignore blobs that have too large a value.
Nyamekye,
mike58smile
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Thu May 30, 2019 8:16 am

Thank you, I will try that soon, but for now I want to order that polarizer to my H7 camera. I want to know if I need more than one and how can it be attached to the camera. I also ordered wide angle lens with my camera, but it cannot be put on camera, it always get stuck in one position. I think that the screw thred is badly made so it always get stuck. I don't know if I need to order new one, or how to deal with this.
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kwagyeman
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby kwagyeman » Thu May 30, 2019 11:02 am

Hi, the polarizer goes under the lens mount. Please order a new lens mount. We have a stock of them that didn't come from the production run. Lens mounts are available on the store.
Nyamekye,
mike58smile
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Thu May 30, 2019 2:09 pm

So the lens mount will also solve the problem with putting on ultra wide lens, I mentioned?
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kwagyeman
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby kwagyeman » Thu May 30, 2019 3:24 pm

Yes, the standard lens mount you have should work with the ultra wide angle lens. It's just that we use really cheap lens mounts which aren't to spec always.
Nyamekye,
mike58smile
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby mike58smile » Sat Jul 06, 2019 6:31 am

Hello, I now have Flir Lepton 3.5 as you adviced me, which example program should I use or what should I do to track the candle fire? Thank you.
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kwagyeman
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Re: Detect a candle fire using OpenMV H7 and FLIR

Postby kwagyeman » Sat Jul 06, 2019 8:10 pm

Hi, please see Examples - > FLIR Lepton -> Target Temperature Tracking. We have about 8 examples to work with.
Nyamekye,

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