+- Gimp-Forum.net (https://www.gimp-forum.net)
+-- Forum: GIMP (https://www.gimp-forum.net/Forum-GIMP)
+--- Forum: Extending the GIMP (https://www.gimp-forum.net/Forum-Extending-the-GIMP)
+--- Thread: Parametric Mask plug-in for GIMP 3 - a different approach (/Thread-Parametric-Mask-plug-in-for-GIMP-3-a-different-approach)
Parametric Mask plug-in for GIMP 3 - a different approach - chuckhenrich - 03-19-2026
Hi all,
I've just released a parametric masking plug-in for GIMP 3 and wanted to share it here.
The plug-in creates a layer mask from one of four source channels: Red, Green, Blue, or Luminance. You shape the mask using a tone curve with a live histogram. Drag points up to include tones, drag them down to exclude them. The canvas updates live as you work.
The curve approach gives you precise, automatically feathered control over the mask. Target midtones, create double peaks, or invert regions entirely. Since photographers already think in curves, there's no new mental model to learn.
The idea was inspired by Yasuo Ohnishi's parametric masking work for GIMP 3. My plug-in takes a different direction, using a curve editor instead of sliders.
A few highlights:
- Red, Green, Blue, and Luminance channel support
- Live preview on the canvas
- Whole-image mode and single-layer mode
- Non-destructive: works on a new layer, never touches the original
- Available in 14 languages
- Runs on Linux, Windows, and macOS
Full write-up with a short demo video: https://www.chuckhenrich.com/parametric-mask-in-gimp-plugin/
Direct download: https://chuckhenrich.com/downloads/parametric-mask-v3/parametric-mask-v3.zip
Happy to answer questions. Feedback and bug reports are very welcome.
RE: Parametric Mask plug-in for GIMP 3 - a different approach - denzjos - 03-19-2026
I have tested the plugin and it is a nice addition to GIMP 3.2.0. Thanks chuckhenrich for the effort and for sharing this plugin.