flirimageextractor 0.0.1

A package to get thermal information out of FLIR radiometric JPGs

Flir Image Extractor

FLIR® thermal cameras like the FLIR ONE® include both a thermal and a visual light camera. The latter is used to enhance the thermal image using an edge detector.

The resulting image is saved as a jpg image but both the original visual image and the raw thermal sensor data are embedded in the jpg metadata.

This small Python tool/library allows to extract the original photo and thermal sensor values converted to temperatures.

Requirements

This tool relies on exiftool. It should be available in most Linux distributions (e.g. as perl-image-exiftool in Arch Linux or libimage-exiftool-perl in Debian and Ubuntu).

It also needs the Python packages numpy and matplotlib (the latter only if used interactively).

sudo apt update
sudo apt install exiftool
sudo pip install numpy matplotlib

Usage

This module can be used by importing it:

import flir_image_extractor
flir = flir_image_extractor.FlirImageExtractor()
flir.process_image('examples/ax8.jpg')
flir.save_image('examples/ax8_thermal.jpg')
flir.plot()

This command will show an interactive plot of the thermal image using matplotlib and create two image files flir_example_thermal.jpg and flir_example_rgb_image.jpg. Both are RGB images, the original temperature array is available using the get_thermal_np or export_thermal_to_csv functions.

The functions get_rgb_np and get_thermal_np yield numpy arrays and can be called from your own script after importing this lib.

The function save_image saves the image at the given filepath

Supported/Tested cameras:

• Flir One (thermal + RGB)
• Xenmuse XTR (thermal + thumbnail, set the subject distance to 1 meter)
• AX8 (thermal + RGB)

Other cameras might need some small tweaks (the embedded raw data can be in multiple image formats)

Credits

Raw value to temperature conversion is ported from this R package: https://github.com/gtatters/Thermimage/blob/master/R/raw2temp.R Original Python code from: https://github.com/Nervengift/read_thermal.py