ente/lib/services/object_detection/object_detection_service.dart
2023-03-15 12:28:25 +05:30

109 lines
3.3 KiB
Dart

import "dart:isolate";
import "dart:typed_data";
import "package:logging/logging.dart";
import "package:photos/services/object_detection/models/predictions.dart";
import 'package:photos/services/object_detection/models/recognition.dart';
import 'package:photos/services/object_detection/tflite/cocossd_classifier.dart';
import "package:photos/services/object_detection/tflite/mobilenet_classifier.dart";
import "package:photos/services/object_detection/tflite/scene_classifier.dart";
import "package:photos/services/object_detection/utils/isolate_utils.dart";
class ObjectDetectionService {
static const scoreThreshold = 0.5;
final _logger = Logger("ObjectDetectionService");
late CocoSSDClassifier _objectClassifier;
late MobileNetClassifier _mobileNetClassifier;
late SceneClassifier _sceneClassifier;
late IsolateUtils _isolateUtils;
ObjectDetectionService._privateConstructor();
Future<void> init() async {
_isolateUtils = IsolateUtils();
await _isolateUtils.start();
_objectClassifier = CocoSSDClassifier();
_mobileNetClassifier = MobileNetClassifier();
_sceneClassifier = SceneClassifier();
}
static ObjectDetectionService instance =
ObjectDetectionService._privateConstructor();
Future<List<String>> predict(Uint8List bytes) async {
try {
final results = <String>{};
final objectResults = await _getObjects(bytes);
results.addAll(objectResults);
final mobileNetResults = await _getMobileNetResults(bytes);
results.addAll(mobileNetResults);
final sceneResults = await _getSceneResults(bytes);
results.addAll(sceneResults);
return results.toList();
} catch (e, s) {
_logger.severe(e, s);
rethrow;
}
}
Future<List<String>> _getObjects(Uint8List bytes) async {
final isolateData = IsolateData(
bytes,
_objectClassifier.interpreter.address,
_objectClassifier.labels,
ClassifierType.cocossd,
);
return _getPredictions(isolateData);
}
Future<List<String>> _getMobileNetResults(Uint8List bytes) async {
final isolateData = IsolateData(
bytes,
_mobileNetClassifier.interpreter.address,
_mobileNetClassifier.labels,
ClassifierType.mobilenet,
);
return _getPredictions(isolateData);
}
Future<List<String>> _getSceneResults(Uint8List bytes) async {
final isolateData = IsolateData(
bytes,
_sceneClassifier.interpreter.address,
_sceneClassifier.labels,
ClassifierType.scenes,
);
return _getPredictions(isolateData);
}
Future<List<String>> _getPredictions(IsolateData isolateData) async {
final predictions = await _inference(isolateData);
final Set<String> results = {};
for (final Recognition result in predictions.recognitions) {
if (result.score > scoreThreshold) {
results.add(result.label);
}
}
_logger.info(
"Time taken for " +
isolateData.type.toString() +
": " +
predictions.stats.totalElapsedTime.toString() +
"ms",
);
return results.toList();
}
/// Runs inference in another isolate
Future<Predictions> _inference(IsolateData isolateData) async {
final responsePort = ReceivePort();
_isolateUtils.sendPort.send(
isolateData..responsePort = responsePort.sendPort,
);
return await responsePort.first;
}
}