[firebase_ml_vision] Add support for cloud text recognizer (flutter#1847)

Author: tatiesmars

packages/firebase_ml_vision/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.9.1
+
+* Add support for cloud text recognizer.
+
 ## 0.9.0+3
 
 * Automatically use version from pubspec.yaml when reporting usage to Firebase.

packages/firebase_ml_vision/android/src/main/java/io/flutter/plugins/firebasemlvision/TextRecognizer.java

@@ -21,7 +21,15 @@ public class TextRecognizer implements Detector {
   private final FirebaseVisionTextRecognizer recognizer;
 
   TextRecognizer(FirebaseVision vision, Map<String, Object> options) {
-    recognizer = vision.getOnDeviceTextRecognizer();
+    final String modelType = (String) options.get("modelType");
+    if (modelType.equals("onDevice")) {
+      recognizer = vision.getOnDeviceTextRecognizer();
+    } else if (modelType.equals("cloud")) {
+      recognizer = vision.getCloudTextRecognizer();
+    } else {
+      final String message = String.format("No model for type: %s", modelType);
+      throw new IllegalArgumentException(message);
+    }
   }
 
   @Override

packages/firebase_ml_vision/example/lib/camera_preview_scanner.dart

@@ -29,6 +29,8 @@ class _CameraPreviewScannerState extends State<CameraPreviewScanner> {
   final ImageLabeler _cloudImageLabeler =
       FirebaseVision.instance.cloudImageLabeler();
   final TextRecognizer _recognizer = FirebaseVision.instance.textRecognizer();
+  final TextRecognizer _cloudRecognizer =
+      FirebaseVision.instance.cloudTextRecognizer();
 
   @override
   void initState() {
@@ -72,6 +74,8 @@ class _CameraPreviewScannerState extends State<CameraPreviewScanner> {
     switch (_currentDetector) {
       case Detector.text:
         return _recognizer.processImage;
+      case Detector.cloudText:
+        return _cloudRecognizer.processImage;
       case Detector.barcode:
         return _barcodeDetector.detectInImage;
       case Detector.label:
@@ -119,7 +123,8 @@ class _CameraPreviewScannerState extends State<CameraPreviewScanner> {
         painter = LabelDetectorPainter(imageSize, _scanResults);
         break;
       default:
-        assert(_currentDetector == Detector.text);
+        assert(_currentDetector == Detector.text ||
+            _currentDetector == Detector.cloudText);
         if (_scanResults is! VisionText) return noResultsText;
         painter = TextDetectorPainter(imageSize, _scanResults);
     }
@@ -200,6 +205,10 @@ class _CameraPreviewScannerState extends State<CameraPreviewScanner> {
                 child: Text('Detect Text'),
                 value: Detector.text,
               ),
+              const PopupMenuItem<Detector>(
+                child: Text('Detect Cloud Text'),
+                value: Detector.cloudText,
+              ),
             ],
           ),
         ],
@@ -222,6 +231,7 @@ class _CameraPreviewScannerState extends State<CameraPreviewScanner> {
       _imageLabeler.close();
       _cloudImageLabeler.close();
       _recognizer.close();
+      _cloudRecognizer.close();
     });
 
     _currentDetector = null;

packages/firebase_ml_vision/example/lib/detector_painters.dart

@@ -7,7 +7,7 @@ import 'dart:ui' as ui;
 import 'package:firebase_ml_vision/firebase_ml_vision.dart';
 import 'package:flutter/material.dart';
 
-enum Detector { barcode, face, label, cloudLabel, text }
+enum Detector { barcode, face, label, cloudLabel, text, cloudText }
 
 class BarcodeDetectorPainter extends CustomPainter {
   BarcodeDetectorPainter(this.absoluteImageSize, this.barcodeLocations);

packages/firebase_ml_vision/example/lib/picture_scanner.dart

@@ -29,6 +29,8 @@ class _PictureScannerState extends State<PictureScanner> {
   final ImageLabeler _cloudImageLabeler =
       FirebaseVision.instance.cloudImageLabeler();
   final TextRecognizer _recognizer = FirebaseVision.instance.textRecognizer();
+  final TextRecognizer _cloudRecognizer =
+      FirebaseVision.instance.cloudTextRecognizer();
 
   Future<void> _getAndScanImage() async {
     setState(() {
@@ -93,6 +95,9 @@ class _PictureScannerState extends State<PictureScanner> {
       case Detector.text:
         results = await _recognizer.processImage(visionImage);
         break;
+      case Detector.cloudText:
+        results = await _cloudRecognizer.processImage(visionImage);
+        break;
       default:
         return;
     }
@@ -121,6 +126,9 @@ class _PictureScannerState extends State<PictureScanner> {
       case Detector.text:
         painter = TextDetectorPainter(_imageSize, results);
         break;
+      case Detector.cloudText:
+        painter = TextDetectorPainter(_imageSize, results);
+        break;
       default:
         break;
     }
@@ -185,6 +193,10 @@ class _PictureScannerState extends State<PictureScanner> {
                 child: Text('Detect Text'),
                 value: Detector.text,
               ),
+              const PopupMenuItem<Detector>(
+                child: Text('Detect Cloud Text'),
+                value: Detector.cloudText,
+              ),
             ],
           ),
         ],
@@ -207,6 +219,7 @@ class _PictureScannerState extends State<PictureScanner> {
     _imageLabeler.close();
     _cloudImageLabeler.close();
     _recognizer.close();
+    _cloudRecognizer.close();
     super.dispose();
   }
 }

packages/firebase_ml_vision/ios/Classes/TextRecognizer.m

@@ -8,7 +8,17 @@ @implementation TextRecognizer
 - (instancetype)initWithVision:(FIRVision *)vision options:(NSDictionary *)options {
   self = [super init];
   if (self) {
-    _recognizer = [vision onDeviceTextRecognizer];
+    if ([@"onDevice" isEqualToString:options[@"modelType"]]) {
+      _recognizer = [vision onDeviceTextRecognizer];
+    } else if ([@"cloud" isEqualToString:options[@"modelType"]]) {
+      _recognizer = [vision cloudTextRecognizer];
+    } else {
+      NSString *reason =
+          [NSString stringWithFormat:@"Invalid model type: %@", options[@"modelType"]];
+      @throw [[NSException alloc] initWithName:NSInvalidArgumentException
+                                        reason:reason
+                                      userInfo:nil];
+    }
   }
   return self;
 }

packages/firebase_ml_vision/lib/src/firebase_vision.dart

@@ -67,7 +67,12 @@ class FirebaseVision {
   }
 
   /// Creates an instance of [TextRecognizer].
-  TextRecognizer textRecognizer() => TextRecognizer._(nextHandle++);
+  TextRecognizer textRecognizer() {
+    return TextRecognizer._(
+      modelType: ModelType.onDevice,
+      handle: nextHandle++,
+    );
+  }
 
   /// Creates a cloud instance of [ImageLabeler].
   ImageLabeler cloudImageLabeler([CloudImageLabelerOptions options]) {
@@ -77,6 +82,14 @@ class FirebaseVision {
       handle: nextHandle++,
     );
   }
+
+  /// Creates a cloud instance of [TextRecognizer].
+  TextRecognizer cloudTextRecognizer() {
+    return TextRecognizer._(
+      modelType: ModelType.cloud,
+      handle: nextHandle++,
+    );
+  }
 }
 
 /// Represents an image object used for both on-device and cloud API detectors.

packages/firebase_ml_vision/lib/src/text_recognizer.dart

@@ -19,7 +19,13 @@ part of firebase_ml_vision;
 ///     await textRecognizer.processImage(image);
 /// ```
 class TextRecognizer {
-  TextRecognizer._(this._handle);
+  TextRecognizer._({
+    @required this.modelType,
+    @required int handle,
+  })  : _handle = handle,
+        assert(modelType != null);
+
+  final ModelType modelType;
 
   final int _handle;
   bool _hasBeenOpened = false;
@@ -35,7 +41,9 @@ class TextRecognizer {
       'TextRecognizer#processImage',
       <String, dynamic>{
         'handle': _handle,
-        'options': <String, dynamic>{},
+        'options': <String, dynamic>{
+          'modelType': _enumToString(modelType),
+        },
       }..addAll(visionImage._serialize()),
     );
 

packages/firebase_ml_vision/pubspec.yaml

@@ -2,7 +2,7 @@ name: firebase_ml_vision
 description: Flutter plugin for Firebase machine learning vision services.
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/firebase_ml_vision
-version: 0.9.0+3
+version: 0.9.1
 
 dependencies:
   flutter: