DJI Thermal Analysis Tool on a Mac: your options for R-JPEG files

DJI's radiometric JPEG, R-JPEG, works on the same principle as FLIR's: a normal colour JPEG that any viewer opens, with the raw thermal data and the parameters needed to turn it into temperature stored in the file's metadata. The encoding is DJI's own, which is why a FLIR tool can't read it and why DJI publishes an SDK for decoding it.

As with any radiometric file, keep the originals. Re-saving an R-JPEG in a photo editor leaves you with the colour picture and no temperatures.

A Windows virtual machine runs DJI Thermal Analysis Tool and is the simplest route if you already own a Windows licence.

DJI Thermal SDK includes a command-line sample that converts an R-JPEG into a raw temperature array, which you can then save as TIFF or CSV. It targets Windows and Linux, so on a Mac it means a Linux container or a second machine, and some scripting.

DJI's mapping and cloud products can process thermal flights, which suits photogrammetry jobs more than single-image inspection.

DJI R-JPEG from the M3T, M30T and H20T is the next format on HeatDeck's list, and the site marks it as coming soon until the parser reads them reliably. When it ships, drone images will open in the same batch as your handheld FLIR and InfiRay / Topdon files, with the same measurements, palette lock and PDF report. If you shoot both handheld and drone, the free tier is useful now for the handheld half.

• Save R-JPEG (radiometric) rather than plain JPEG in the camera settings.
• Set emissivity and distance before the flight if you can; you can correct them afterwards, but defaults help.
• Fly roof surveys after sunset or before sunrise, when solar loading has gone and moisture shows as a temperature difference.
• Keep the visual images: a report without them is hard for a client to read.