Preview coordinate mapping + Object Detector example (0.0.6)

.pubignore

@@ -5,6 +5,10 @@
 # Demo media
 doc/
 
+# The example's bundled ML model (git-tracked so the example runs, but ~5 MB —
+# kept out of the published package).
+**/*.tflite
+
 # Build & tooling artifacts (mirrors .gitignore)
 build/
 **/build/

CHANGELOG.md

@@ -1,5 +1,17 @@
 # Changelog
 
+## 0.0.6
+
+* **New:** `CameraController.previewRectFromFrame(rect, sourceRotationDegrees:)` maps a normalized
+  detection box from a frame's coordinate space into preview-display space, accounting for the live preview
+  rotation and the front-camera mirror — so ML overlays line up with the preview **at any device
+  orientation** (the preview rotation and frame orientation are tracked independently, so boxes drawn
+  without it drift as the phone turns).
+* **Example:** added a real-time **Object Detector** page — the FFI frame pipeline drives an on-device
+  EfficientDet-Lite0 detector (90 COCO classes) in a background isolate, with labelled boxes and a
+  cat-certainty voting trigger. Demonstrates YUV→RGB preprocessing, isolate inference, and
+  `previewRectFromFrame` for correctly-oriented overlays.
+
 ## 0.0.5
 
 * **Docs:** added demo GIFs to the README (live preview + orientation, barcode/QR scanning with overlay,

README.md

@@ -229,6 +229,24 @@ frame.incrementRefCount();              // keep the buffer alive
 frame.decrementRefCount();              // release it (mandatory)
 ```
 
+### Drawing ML detection boxes on the preview
+
+Detection boxes are in the frame's coordinate space; the preview is rotated (and
+maybe mirrored) for display, and the two are tracked **independently** — so a box
+drawn naively drifts as the device turns. Map it with `previewRectFromFrame`:
+
+```dart
+final previewRect = controller.previewRectFromFrame(
+  detection.boundingBox,                      // normalized 0..1 from your model
+  sourceRotationDegrees: frame.orientation.degrees, // rotation you fed the model
+);
+// Scale previewRect onto the preview widget's rect (use displayPreviewSize for BoxFit).
+```
+
+It accounts for the live `previewRotation` and the front-camera mirror, so boxes
+stay aligned at any orientation. See the example's **Object Detector** page for a
+full EfficientDet-Lite0 overlay.
+
 ### High-performance native C/C++ plugin
 
 For the heaviest work, hook the synchronous frame loop in C++ (`src/VisionCamera.hpp`):

android/build.gradle

@@ -1,7 +1,7 @@
 // The Android Gradle Plugin builds the native code with the Android NDK.
 
 group = "dev.jentejan.flutter_native_vision_camera"
-version = "0.0.5"
+version = "0.0.6"
 
 buildscript {
     repositories {

example/android/gradle.properties

@@ -1,6 +1,10 @@
 org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
 android.useAndroidX=true
 android.enableJetifier=true
+# Some plugins (e.g. tflite_flutter 0.11.x) leave Java at 1.8 while Kotlin uses
+# the toolchain's 21. On Android everything dexes to the same level, so downgrade
+# the JVM-target consistency check from a hard error to a warning.
+kotlin.jvm.target.validation.mode=warning
 # This builtInKotlin flag was added automatically by Flutter migrator
 android.builtInKotlin=false
 # This newDsl flag was added automatically by Flutter migrator

example/assets/coco_labels.txt

@@ -0,0 +1,90 @@
+person
+bicycle
+car
+motorcycle
+airplane
+bus
+train
+truck
+boat
+traffic light
+fire hydrant
+???
+stop sign
+parking meter
+bench
+bird
+cat
+dog
+horse
+sheep
+cow
+elephant
+bear
+zebra
+giraffe
+???
+backpack
+umbrella
+???
+???
+handbag
+tie
+suitcase
+frisbee
+skis
+snowboard
+sports ball
+kite
+baseball bat
+baseball glove
+skateboard
+surfboard
+tennis racket
+bottle
+???
+wine glass
+cup
+fork
+knife
+spoon
+bowl
+banana
+apple
+sandwich
+orange
+broccoli
+carrot
+hot dog
+pizza
+donut
+cake
+chair
+couch
+potted plant
+bed
+???
+dining table
+???
+???
+toilet
+???
+tv
+laptop
+mouse
+remote
+keyboard
+cell phone
+microwave
+oven
+toaster
+sink
+refrigerator
+???
+book
+clock
+vase
+scissors
+teddy bear
+hair drier
+toothbrush

example/ios/Podfile.lock

@@ -1,14 +1,42 @@
 PODS:
   - Flutter (1.0.0)
-  - flutter_native_vision_camera (0.0.4):
+  - flutter_native_vision_camera (0.0.5):
     - Flutter
   - permission_handler_apple (9.3.0):
     - Flutter
+  - TensorFlowLiteC (2.12.0):
+    - TensorFlowLiteC/Core (= 2.12.0)
+  - TensorFlowLiteC/Core (2.12.0)
+  - TensorFlowLiteC/CoreML (2.12.0):
+    - TensorFlowLiteC/Core
+  - TensorFlowLiteC/Metal (2.12.0):
+    - TensorFlowLiteC/Core
+  - TensorFlowLiteSwift (2.12.0):
+    - TensorFlowLiteSwift/Core (= 2.12.0)
+  - TensorFlowLiteSwift/Core (2.12.0):
+    - TensorFlowLiteC (= 2.12.0)
+  - TensorFlowLiteSwift/CoreML (2.12.0):
+    - TensorFlowLiteC/CoreML (= 2.12.0)
+    - TensorFlowLiteSwift/Core (= 2.12.0)
+  - TensorFlowLiteSwift/Metal (2.12.0):
+    - TensorFlowLiteC/Metal (= 2.12.0)
+    - TensorFlowLiteSwift/Core (= 2.12.0)
+  - tflite_flutter (0.0.1):
+    - Flutter
+    - TensorFlowLiteSwift (= 2.12.0)
+    - TensorFlowLiteSwift/CoreML (= 2.12.0)
+    - TensorFlowLiteSwift/Metal (= 2.12.0)
 
 DEPENDENCIES:
   - Flutter (from `Flutter`)
   - flutter_native_vision_camera (from `.symlinks/plugins/flutter_native_vision_camera/ios`)
   - permission_handler_apple (from `.symlinks/plugins/permission_handler_apple/ios`)
+  - tflite_flutter (from `.symlinks/plugins/tflite_flutter/ios`)
+
+SPEC REPOS:
+  trunk:
+    - TensorFlowLiteC
+    - TensorFlowLiteSwift
 
 EXTERNAL SOURCES:
   Flutter:
@@ -17,11 +45,16 @@ EXTERNAL SOURCES:
     :path: ".symlinks/plugins/flutter_native_vision_camera/ios"
   permission_handler_apple:
     :path: ".symlinks/plugins/permission_handler_apple/ios"
+  tflite_flutter:
+    :path: ".symlinks/plugins/tflite_flutter/ios"
 
 SPEC CHECKSUMS:
   Flutter: cabc95a1d2626b1b06e7179b784ebcf0c0cde467
-  flutter_native_vision_camera: f9cae7b27180d93bf6fafad999e37e5086ae477a
+  flutter_native_vision_camera: 241fc00d5a123d3e560daa047824120dd6af5c03
   permission_handler_apple: 4ed2196e43d0651e8ff7ca3483a069d469701f2d
+  TensorFlowLiteC: 20785a69299185a379ba9852b6625f00afd7984a
+  TensorFlowLiteSwift: 3a4928286e9e35bdd3e17970f48e53c80d25e793
+  tflite_flutter: 64b192e11352fe36943ab6656e1d49207f1a5595
 
 PODFILE CHECKSUM: 3c63482e143d1b91d2d2560aee9fb04ecc74ac7e
 

example/lib/main.dart

@@ -3,6 +3,7 @@ import 'package:flutter_native_vision_camera/flutter_native_vision_camera.dart';
 import 'native_camera_page.dart';
 import 'standard_camera_page.dart';
 import 'code_scanner_page.dart';
+import 'object_detector_page.dart';
 
 import 'package:flutter/services.dart';
 
@@ -83,6 +84,19 @@ class _HomePageState extends State<HomePage> {
               },
             ),
             const SizedBox(height: 16),
+            _buildFeatureCard(
+              context,
+              title: 'Object Detector',
+              subtitle: 'Frame processor → EfficientDet (90 classes) + boxes',
+              icon: Icons.center_focus_strong,
+              color: Colors.deepPurple,
+              onTap: () {
+                Navigator.of(context).push(
+                  MaterialPageRoute(builder: (_) => const ObjectDetectorPage()),
+                );
+              },
+            ),
+            const SizedBox(height: 16),
             _buildFeatureCard(
               context,
               title: 'Standard Camera',