feat: port object detection to C++ (#361)

## Description

Port object detection native code to C++

### Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Documentation update (improves or adds clarity to existing
documentation)

### Tested on

- [x] iOS
- [x] Android

### Related issues

#260 #255

### Checklist

- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have updated the documentation accordingly
- [x] My changes generate no new warnings

Author: JakubGonera

packages/react-native-executorch/android/src/main/java/com/swmansion/rnexecutorch/ObjectDetection.kt

@@ -18,8 +18,6 @@ class RnExecutorchPackage : TurboReactPackage() {
       LLM(reactContext)
     } else if (name == ETModule.NAME) {
       ETModule(reactContext)
-    } else if (name == ObjectDetection.NAME) {
-      ObjectDetection(reactContext)
     } else if (name == SpeechToText.NAME) {
       SpeechToText(reactContext)
     } else if (name == OCR.NAME) {
@@ -60,17 +58,6 @@ class RnExecutorchPackage : TurboReactPackage() {
           true,
         )
 
-      moduleInfos[ObjectDetection.NAME] =
-        ReactModuleInfo(
-          ObjectDetection.NAME,
-          ObjectDetection.NAME,
-          false, // canOverrideExistingModule
-          false, // needsEagerInit
-          true, // hasConstants
-          false, // isCxxModule
-          true,
-        )
-
       moduleInfos[SpeechToText.NAME] =
         ReactModuleInfo(
           SpeechToText.NAME,

packages/react-native-executorch/android/src/main/java/com/swmansion/rnexecutorch/RnExecutorchPackage.kt

@@ -3,6 +3,7 @@
 #include <rnexecutorch/host_objects/JsiConversions.h>
 #include <rnexecutorch/models/classification/Classification.h>
 #include <rnexecutorch/models/image_segmentation/ImageSegmentation.h>
+#include <rnexecutorch/models/object_detection/ObjectDetection.h>
 #include <rnexecutorch/models/style_transfer/StyleTransfer.h>
 
 namespace rnexecutorch {
@@ -31,5 +32,10 @@ void RnExecutorchInstaller::injectJSIBindings(
       *jsiRuntime, "loadClassification",
       RnExecutorchInstaller::loadModel<Classification>(
           jsiRuntime, jsCallInvoker, "loadClassification"));
+
+  jsiRuntime->global().setProperty(
+      *jsiRuntime, "loadObjectDetection",
+      RnExecutorchInstaller::loadModel<ObjectDetection>(
+          jsiRuntime, jsCallInvoker, "loadObjectDetection"));
 }
 } // namespace rnexecutorch

packages/react-native-executorch/android/src/main/java/com/swmansion/rnexecutorch/models/objectDetection/SSDLiteLargeModel.kt

@@ -111,6 +111,7 @@ cv::Mat readImage(const std::string &imageURI) {
     throw std::runtime_error("Read image error: invalid argument");
   }
 
+  cv::cvtColor(image, image, cv::COLOR_BGR2RGB);
   return image;
 }