Masks

Masks let you adjust one part of the photo: brighten a face, darken the sky, warm the foreground. Each mask has its own set of sliders.

If you’ve used another editor: this is the usual masking panel. It has the usual tools (AI Subject, Sky, Background, People, Select Object, brush, linear and radial gradients, color, luminance and depth ranges) and the same keys: K brush, M linear, ⇧M radial, ⇧J color range, ⇧Q luminance range, O overlay.

Open it with Masks on the rail, or press one of the tool keys.

Creating a mask

Click Create New Mask and choose:

• AI tools find the area for you. The first time you use one, its model downloads (“first use only”), which takes a moment. Select Object: click the object, or drag a box around it. Background is the subject’s outline, inverted.
• Brush: paint; hold ⌥ to erase.
• Linear Gradient: drag across the photo where the change should happen.
• Radial Gradient: drag out an ellipse, or click for a circle.
• Color Range, Luminance Range and Depth Range: click the photo on the color, brightness or distance to select.

A new mask is named after its kind, such as Sky or Radial. Make a second of the same kind and they become Radial 1 and Radial 2.

Shaping a mask

Select a mask, then use + to add to it or − to subtract from it, with any of the same tools. Under +, the ranges are listed under Intersect: they narrow the mask to a color, brightness or depth within it. For example, add a Sky mask, then intersect a Luminance Range to keep only its bright clouds.

Each part of the mask is listed under it, with a + / − switch and × to delete it.

On the photo, drag a shape’s handles: the center moves it, the edges size it, the arrow rotates it, and the outer ring sets its feather. The handles show while the pointer is over the photo, and step aside while it is over the panels, so the adjustment can be seen.

The mask list

• The eye shows or hides the mask’s adjustments.
• Hover over a name for a moment to see that mask in red.
• Double-click a name to rename it.
• The … menu has Duplicate Mask, Duplicate and Invert Mask, Rename Mask and Delete Mask.
• O, or the eye in the panel’s title, shows or hides the red overlay. While you add to or subtract from a mask, its overlay shows even with the toggle off; O hides it until you put the tool down, and moving one of the mask’s sliders hides it until your next stroke. A mask an AI selection has just made shows its overlay too, so you can see what was selected, until you press O or move one of its sliders.

Mask settings

• Invert: adjust everything except the mask.
• Opacity: 0-100%, how strongly the mask’s adjustments apply.
• Refine:
  • Edge Aware: softens the edge so it follows edges in the photo
  • Blur: softens the edge
  • Detail: keeps the mask to detailed areas, or flat ones (raws only)
  • Contrast: hardens or softens the mask’s falloff
• A part’s own settings: Feather for brushes, radial gradients and objects; Near, Far and Feather for depth; Low (EV), High (EV) and Smoothness for luminance; Refine and Smoothness for color.

The brush

Size (0.5-40% of the photo), Feather (0-100), Density (1-100) and Erase (hold ⌥).

Parametric

Parametric selects by darktable’s blending channels: gray, red, green, blue, and lightness, chroma and hue (Jz, Cz, hz). Each channel has a slider with four markers that set the range and its soft edges, and a + / − switch for inside or outside it. Drag a box on the photo to set a channel from it. Boost raises the range for bright highlights, and Invert Polarities flips every channel. Double-click a channel to reset it.

Adjusting inside a mask

The selected mask’s sliders sit below its settings, in six groups:

• White Balance: Temp, Tint
• Tone: Exposure (±4), Contrast, Highlights, Shadows, Whites, Blacks
• Presence: Texture, Clarity, Dehaze, Hue, Saturation
• HSL: Hue, Saturation and Luminance tabs, each with the eight color bands
• Color Grading: 3-Way, Global or Sliders, for shadows, midtones, highlights and global
• Detail: Sharpening, Noise, Defringe

They work like the same sliders in Adjustments, only inside the mask. A new mask opens its Tone group.

Choose mask modules independently of global adjustments under Preferences › Modules › Masks. Alternatives are available for Contrast, Highlights and Shadows, Clarity, Texture, Sharpening, and Defringe. Used mask adjustments keep their modules when preferences change; new masks and unused tools take the current mask choices. Whites is the exception: the photo’s Whites moves the top of the tone mapper’s curve, which can’t run inside a mask, so a mask’s Whites only brightens or darkens its brightest tones, as the photo’s Whites also does under AgX.

Where masks overlap, their adjustments add up. Contrast, Saturation, Whites, Color Grading, HSL, Texture, Noise and Defringe add up only to the end of their own slider, so two masks at +80 Contrast give +100 where they meet.

Keys

Clarity and Texture also offer contrast & texture, chosen independently in Preferences › Modules. Medium and Fine details stay visible; Advanced reveals the remaining native controls. Contrast equalizer can also replace mask Contrast: select Custom, then Masks › Contrast › contrast equalizer. The mask’s Tone group shows the same five-channel, six-band graph described in Adjustments, applied only inside that mask. Global Contrast can still use AgX. Masked equalizer instances run separately; the slider-based overlap limits described above apply to color balance rgb Contrast.

Object selections use the same model folder as the other AI tools. A model downloaded during the current session is available immediately; restarting the app is unnecessary. Existing valid models are reused.

Reporting an AI model loading error on Linux

If an AI tool repeatedly downloads its model and then says it cannot load it, use the diagnostic script to capture the native loading error. Subject and Select Object use different models, so one can work while another fails.

1. Close Immage. Copy app/scripts/diagnose_ai_appimage.sh from the source repository to the affected machine, beside your AppImage.

2. In a terminal in that folder, run:

   sh diagnose_ai_appimage.sh ./Immage.AppImage

   Replace the AppImage filename with yours.

3. Try one Object mask, wait for the error, then close Immage. Avoid in-app Relaunch during this diagnostic run.

4. Share the immage-ai-report.*.tar.gz file created in that folder.

The report contains AI and launcher logs, platform information and Object model file sizes, checksums and configuration. It contains no photos or model weights. Logs can include local file paths. The debug switch applies only to this launch; the script does not change saved preferences or delete model files. The app’s normal automatic model recovery can still download the model during the test.

This page is part of immage's own docs, at v0.41.1. View the source on GitHub.