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Published 20 hours ago • verified publisher icon detecttechnologies

meta data is overwirtten with constant data

Open najtin opened this issue 3 years ago • 11 comments

Hi, i just stumbled upon this project so i am not sure if i understand correctly.

To me this seems wrong: https://github.com/detecttechnologies/thermal_base/blob/main/thermal_base/thermal_base.py#L110-L125

I am going to try to built it myself and report back.

najtin avatar Jul 30 '21 12:07 najtin

It seems like someone had at least partial success in reverse engineering the important meta data: https://exiftool.org/forum/index.php?topic=11401.0

najtin avatar Jul 30 '21 13:07 najtin

Hey @najtin

Yes absolutely, it would be better if we can extract the formula params from the metadata itself for the DJI encoding too. Would you be interested in contributing the same?

rsnk96 avatar Jul 30 '21 17:07 rsnk96

Yes i will take a look into that. Though i have no experience in reverse engineering and it would be a side project for me. :D

najtin avatar Jul 31 '21 19:07 najtin

Haha well, all the best, hope you figure it out! 🙂

rsnk96 avatar Aug 02 '21 15:08 rsnk96

Hi, Regarding the same issue, DJI released SDK that allows extracting the information from images taken by H20T and XTS but does not yet support M2EA. According to this thread, one of their developers says they will release a version that supports M2EA in the second half of 2021. The formula that DJI used to calculate the temperatures in deg C is different than the one that you should use for FLIR data.

omritz avatar Sep 02 '21 09:09 omritz

Thanks for sharing @omritz . Will look into integrating that!

rsnk96 avatar Sep 06 '21 16:09 rsnk96

Hey @omritz - the DJI SDK has been integrated by @agarwalkunal12 for fetching the raw sensor values 😃

rsnk96 avatar Oct 05 '21 12:10 rsnk96

Can you test it out, and share how it compares to using the DJI Thermal Analysis tool?

rsnk96 avatar Oct 05 '21 12:10 rsnk96

Thanks for the update. When I test it with the new M2EA support and adjust the same parameters, the results are not the same as the DJI thermal analysis tool. For the same image: DJI Thermal Analysis - max=55.3, min=16.8, avg=35.1 Thermal_base - max=38.2, min=26.7 , avg=32.2

omritz avatar Dec 29 '21 11:12 omritz

@agarwalkunal12 - any thoughts on this? Could this be because of the assumptions made for the missing metadata?

rsnk96 avatar Dec 30 '21 19:12 rsnk96

Perhaps this could be because DJI's SDK is not called when M2EA images are processed by thermal_tools?

nrontsis avatar Jan 19 '22 17:01 nrontsis