Add image extraction functionality with background removal

- Implemented ExtractImageRegion operator for extracting image regions using box or lasso selection.
- Added RemoveImageRegionBackground job for background removal from selected image regions.
- Created utility functions for polygon bounds, selection canvas creation, and applying selection masks.
- Integrated image processing using PIL and numpy for efficient pixel manipulation.
- Enhanced user experience with modal drawing and status updates during extraction.

src/anyimage/properties.py

@@ -280,25 +280,27 @@ def balloon_contour_analysis_property():
     )
 
 
-def image_lasso_contour_analysis_property():
+def image_extract_remove_background_property():
     return bpy.props.BoolProperty(
-        name="Contour",
+        name="Remove Background",
         description=(
-            "Use BEN2 to refine the lasso Alpha while preserving the source colors"
+            "Use BEN2 to remove the background inside the selected image region"
         ),
         default=False,
     )
 
 
-def image_lasso_keep_original_property():
+def image_extract_continuous_property():
     return bpy.props.BoolProperty(
-        name="Keep Original",
-        description="Keep the source Image Empty and create a cropped copy",
+        name="Continuous",
+        description=(
+            "Keep the source Image Empty active and continuously create extracted copies"
+        ),
         default=False,
     )
 
 
-def image_lasso_padding_property():
+def image_extract_padding_property():
     return bpy.props.IntProperty(
         name="Padding",
         description="Transparent padding in pixels around the visible Alpha bounds",
@@ -335,9 +337,9 @@ def balloon_radial_zoom_property(scale):
 
 
 class AnyImageSettings(bpy.types.PropertyGroup):
-    image_lasso_contour_analysis: image_lasso_contour_analysis_property()
-    image_lasso_keep_original: image_lasso_keep_original_property()
-    image_lasso_padding: image_lasso_padding_property()
+    image_extract_remove_background: image_extract_remove_background_property()
+    image_extract_continuous: image_extract_continuous_property()
+    image_extract_padding: image_extract_padding_property()
     balloon_mode: balloon_mode_property()
     balloon_thickness: balloon_thickness_property()
     balloon_resolution: balloon_resolution_property()