Request for RawThermalImage support of H20T camera

[EE]

The Zenmuse H20T camera captures R-JPEG (https://www.dji.com/be/downloads/products/zenmuse-h20-series) but I am unable to extract the 16-bit raw data. The data is readable using `DJI Thermal Analysis Tool` (https://www.dji.com/be/zenmuse-h20-series/downloads).
Could ExifTool help me extract the 16 bit data?

It seems like there are 2 TIFF headers in the file.
I have no idea what APP3/APP4/APP5 are (could be these?)
The PreviewImage seems to also be 8bit (slight shift compared to the original jpg) `[MPImage2]      PreviewImage                    : (Binary data 191087 bytes, use -b option to extract)`. (So PreviewImage is not coming from APP3 I believe)

[Jonathan McGillivray]

See my post on this topic: https://exiftool.org/forum/index.php?topic=11401.msg61059#msg61059

The 16 bit raw sensor data is stored within the APP3 segment. These raw values need to be corrected within a formula which combines the calibration data with other settings such as emissivity, distance etc. to convert the raw values to actual temperatures (similar to Flir's R-JPEG images). Phil thinks the calibration data may be stored within the APP4 segment. If we could decode this then hopefully we could apply a similar formula as to the one used on Flir images: https://exiftool.org/forum/index.php?topic=4898.60

I've tried to take a look at decoding the APP4 segment but haven't had any luck so far. It's quite out of my depth looking at the binary data. If somebody with more experience could help I think we might be able to come right.