A set of image utils geared towards game development and handling of various PBR texture types.
Last tested with Python 3.11 on Windows.
Game engines (Unity, Unreal, etc) use shaders that require a specific packed texture format. For example, Unity requires metallic data packed in the (R) channel, and smoothness packed in the (A) channel. However, some assets may only provide a roughness map, meaning you must first invert that roughness map to create a smoothness map, and then set that smoothness map as the alpha channel of a metallic map.
Place images in images/. By default, scripts search images/ for relative image file paths.
python add-image-to-alpha-channel.py -rgb specular.png -a smoothness.png
Linear to Gamma:
python add-image-to-alpha-channel.py -rgb specular.png -a smoothness.png --suffix smoothness --exponent_power 0.454545
Gamma to Linear:
python add-image-to-alpha-channel.py -rgb specular.png -a smoothness.png --suffix smoothness --exponent_power 2.2
Invert RGB channels:
python invert-channels.py -i roughness.png -c rgb
Invert Alpha channel:
python invert-channels.py -i metallic_roughness.png -c a
python resize-image.py -i image.png --width 2048 --height 1024
python extract-channel-and-save-as-image.py -i OcclusionRoughnessMetallic.png -c r