Flutter 苹果视觉对象识别插件 apple_vision_object 的使用

apple_vision_object

Apple Vision 自拍检测是一个 Flutter 插件，使 Flutter 应用能够使用 Apple Vision 自拍检测。

• 该插件并非由 Apple 赞助或维护。作者是希望为 macOS 创建类似 Google ML Kit 的开发者。

要求

MacOS

• 最低 osx 部署目标：10.13
• Xcode 13 或更新版本
• Swift 5
• ML Kit 仅支持 64 位架构（x86_64 和 arm64）

iOS

• 最低 osx 部署目标：14.0
• Xcode 13 或更新版本
• Swift 5
• ML Kit 仅支持 64 位架构（x86_64 和 arm64）

开始使用

首先需要导入 'package:apple_vision/apple_vision.dart';

final GlobalKey cameraKey = GlobalKey(debugLabel: "cameraKey");
AppleVisionObjectController visionController = AppleVisionObjectController();
InsertCamera camera = InsertCamera();
Size imageSize = const Size(640, 640 * 9 / 16);
String? deviceId;
bool loading = true;

List<ObjectData>? objectData;
late double deviceWidth;
late double deviceHeight;

[@override](/user/override)
void initState() {
  camera.setupCameras().then((value) {
    setState(() {
      loading = false;
    });
    camera.startLiveFeed((InputImage i) {
      if (i.metadata?.size != null) {
        imageSize = i.metadata!.size;
      }
      if (mounted) {
        Uint8List? image = i.bytes;
        visionController.processImage(image!, imageSize).then((data) {
          objectData = data;
          // print(objectData!.objects);
          setState(() {});
        });
      }
    });
  });
  super.initState();
}

[@override](/user/override)
void dispose() {
  camera.dispose();
  super.dispose();
}

[@override](/user/override)
Widget build(BuildContext context) {
  deviceWidth = MediaQuery.of(context).size.width;
  deviceHeight = MediaQuery.of(context).size.height;
  return Stack(
    children: [
      SizedBox(
        width: imageSize.width,
        height: imageSize.height,
        child: loading ? Container() : CameraSetup(camera: camera, size: imageSize)
      ),
    ] + showRects()
  );
}

List<Widget> showRects() {
  if (objectData == null || objectData!.isEmpty) return [];
  List<Widget> widgets = [];

  for (int i = 0; i < objectData!.length; i++) {
    // if(objectData!.objects[i]. confidence > 0.5){
      widgets.add(
        Positioned(
          top: objectData![i].object.top,
          left: objectData![i].object.left,
          child: Container(
            width: objectData![i].object.width * imageSize.width,
            height: objectData![i].object.height * imageSize.height,
            decoration: BoxDecoration(
              color: Colors.transparent,
              border: Border.all(width: 1, color: Colors.green),
              borderRadius: BorderRadius.circular(5)
            ),
            child: Text(
              '${objectData![i].label}: ${objectData![i].confidence}',
              style: const TextStyle(
                color: Colors.white,
                fontSize: 12
              ),
            )
          )
        )
      );
    //}
  }
  return widgets;
}

Widget loadingWidget() {
  return Container(
    width: deviceWidth,
    height: deviceHeight,
    color: Theme.of(context).canvasColor,
    alignment: Alignment.center,
    child: const CircularProgressIndicator(color: Colors.blue)
  );
}

示例

完整的示例代码可以在以下链接找到： example/lib/main.dart

import 'package:apple_vision_object/apple_vision_object.dart';
import 'package:flutter/material.dart';
import '../camera/camera_insert.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart';
import 'camera/input_image.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const VisionObject(),
    );
  }
}

class VisionObject extends StatefulWidget {
  const VisionObject({
    Key? key,
    this.onScanned
  }) : super(key: key);

  final Function(dynamic data)? onScanned; 

  [@override](/user/override)
  _VisionObject createState() => _VisionObject();
}

class _VisionObject extends State<VisionObject> {
  final GlobalKey cameraKey = GlobalKey(debugLabel: "cameraKey");
  AppleVisionObjectController visionController = AppleVisionObjectController();
  InsertCamera camera = InsertCamera();
  Size imageSize = const Size(640, 640 * 9 / 16);
  String? deviceId;
  bool loading = true;

  List<ObjectData>? objectData;
  late double deviceWidth;
  late double deviceHeight;

  [@override](/user/override)
  void initState() {
    camera.setupCameras().then((value) {
      setState(() {
        loading = false;
      });
      camera.startLiveFeed((InputImage i) {
        if (i.metadata?.size != null) {
          imageSize = i.metadata!.size;
        }
        if (mounted) {
          Uint8List? image = i.bytes;
          visionController.processImage(image!, imageSize).then((data) {
            objectData = data;
            // print(objectData!.objects);
            setState(() {});
          });
        }
      });
    });
    super.initState();
  }

  [@override](/user/override)
  void dispose() {
    camera.dispose();
    super.dispose();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    deviceWidth = MediaQuery.of(context).size.width;
    deviceHeight = MediaQuery.of(context).size.height;
    return Stack(
      children: [
        SizedBox(
          width: imageSize.width,
          height: imageSize.height,
          child: loading ? Container() : CameraSetup(camera: camera, size: imageSize)
        ),
      ] + showRects()
    );
  }

  List<Widget> showRects() {
    if (objectData == null || objectData!.isEmpty) return [];
    List<Widget> widgets = [];

    for (int i = 0; i < objectData!.length; i++) {
      // if(objectData!.objects[i]. confidence > 0.5){
        widgets.add(
          Positioned(
            top: objectData![i].object.top,
            left: objectData![i].object.left,
            child: Container(
              width: objectData![i].object.width * imageSize.width,
              height: objectData![i].object.height * imageSize.height,
              decoration: BoxDecoration(
                color: Colors.transparent,
                border: Border.all(width: 1, color: Colors.green),
                borderRadius: BorderRadius.circular(5)
              ),
              child: Text(
                '${objectData![i].label}: ${objectData![i].confidence}',
                style: const TextStyle(
                  color: Colors.white,
                  fontSize: 12
                ),
              )
            )
          )
        );
      //}
    }
    return widgets;
  }

  Widget loadingWidget() {
    return Container(
      width: deviceWidth,
      height: deviceHeight,
      color: Theme.of(context).canvasColor,
      alignment: Alignment.center,
      child: const CircularProgressIndicator(color: Colors.blue)
    );
  }
}