[AI] AI object mask tool

data/ai_models.json

@@ -1,5 +1,21 @@
 {
   "version": 1,
   "models": [
-    ]
+    {
+      "id": "mask-object-sam21-small",
+      "name": "mask sam2.1 hiera small",
+      "description": "Segment Anything 2.1 (Hiera Small) for interactive masking",
+      "task": "mask",
+      "github_asset": "mask-object-sam21-small.dtmodel",
+      "default": true
+    },
+    {
+      "id": "mask-object-segnext-b2hq",
+      "name": "mask segnext vitb-sax2 hq",
+      "description": "SegNext ViT-B SAx2 HQ fine-tuned for interactive masking",
+      "task": "mask",
+      "github_asset": "mask-object-segnext-b2hq.dtmodel",
+      "default": false
+    }
+  ]
 }

data/darktableconfig.xml.in

@@ -3501,6 +3501,55 @@
     <shortdescription>height of mask manager view window</shortdescription>
     <longdescription>maximum height the masks view in darkroom will grow to before scrolling</longdescription>
   </dtconfig>
+  <dtconfig>
+    <name>plugins/darkroom/masks/object/cleanup</name>
+    <type min="0" max="100">int</type>
+    <default>10</default>
+    <shortdescription>AI mask cleanup</shortdescription>
+    <longdescription>area (in pixels²) of the largest speckle to suppress during AI mask vectorization. higher values remove more small artifacts.</longdescription>
+  </dtconfig>
+  <dtconfig>
+    <name>plugins/darkroom/masks/object/smoothing</name>
+    <type min="0.0" max="1.3">float</type>
+    <default>1.0</default>
+    <shortdescription>AI mask smoothing</shortdescription>
+    <longdescription>corner threshold for AI mask vectorization. 0 = all sharp corners (most points), 1.0 = balanced, 1.3 = maximum smoothing (fewest points).</longdescription>
+  </dtconfig>
+  <dtconfig>
+    <name>plugins/darkroom/masks/object/refine_passes</name>
+    <type min="1" max="5">int</type>
+    <default>1</default>
+    <shortdescription>AI mask refinement passes</shortdescription>
+    <longdescription>number of iterative decoder passes. each pass feeds back the mask to tighten boundaries. higher values give tighter edges at the cost of more processing time.</longdescription>
+  </dtconfig>
+  <dtconfig>
+    <name>plugins/darkroom/masks/object/threshold</name>
+    <type min="0.3" max="0.9">float</type>
+    <default>0.5</default>
+    <shortdescription>AI mask binarization threshold</shortdescription>
+    <longdescription>sigmoid threshold for converting AI mask to binary. higher values (0.6-0.7) tighten boundaries, lower values include more area.</longdescription>
+  </dtconfig>
+  <dtconfig>
+    <name>plugins/darkroom/masks/object/morph_radius</name>
+    <type min="0" max="5">int</type>
+    <default>3</default>
+    <shortdescription>AI mask morphological cleanup radius</shortdescription>
+    <longdescription>radius of structuring element for morphological open+close cleanup. removes small protrusions and fills small holes in the mask. 0 = disabled, 1-3 = typical values.</longdescription>
+  </dtconfig>
+  <dtconfig>
+    <name>plugins/darkroom/masks/object/edge_refine</name>
+    <type min="0.0" max="0.5">float</type>
+    <default>0.2</default>
+    <shortdescription>AI mask edge refinement</shortdescription>
+    <longdescription>strength of edge-aware threshold boost. near strong image edges the binarization threshold is raised, snapping the mask boundary to object edges. 0 = disabled, 0.1-0.3 = typical values.</longdescription>
+  </dtconfig>
+  <dtconfig>
+    <name>plugins/darkroom/masks/object/brush_size</name>
+    <type min="0.005" max="0.5">float</type>
+    <default>0.03</default>
+    <shortdescription>AI mask brush size</shortdescription>
+    <longdescription>brush radius as a fraction of the shorter image dimension. used for the brush tool in the AI object mask to paint over the target object.</longdescription>
+  </dtconfig>
   <dtconfig>
     <name>plugins/darkroom/ashift/near_delta</name>
     <type>float</type>

src/CMakeLists.txt

@@ -461,6 +461,7 @@ if(USE_AI)
 
   FILE(GLOB SOURCE_FILES_AI
     "common/ai_models.c"
+    "develop/masks/object.c"
     "gui/preferences_ai.c"
   )
   set(SOURCES ${SOURCES} ${SOURCE_FILES_AI})

src/ai/CMakeLists.txt

@@ -4,6 +4,8 @@ add_library(darktable_ai STATIC
   backend.h
   backend_common.c
   backend_onnx.c
+  segmentation.h
+  segmentation.c
 )
 
 # Find ONNX Runtime (auto-downloads if not present)