body_detection 0.0.3

A flutter plugin that uses MLKit on iOS/Android platforms to enable body pose and mask detection using Pose Detection and Selfie Segmentation APIs for both static images and live camera stream.

example/lib/main.dart

import 'dart:io';
import 'dart:typed_data';

import 'package:body_detection/models/image_result.dart';
import 'package:body_detection/models/pose.dart';
import 'package:body_detection/models/body_mask.dart';
import 'package:body_detection/png_image.dart';
import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'dart:ui' as ui;

import 'package:body_detection/body_detection.dart';
import 'package:permission_handler/permission_handler.dart';

import 'pose_mask_painter.dart';

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

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  int _selectedTabIndex = 0;

  bool _isDetectingPose = false;
  bool _isDetectingBodyMask = false;

  Image? _selectedImage;

  Pose? _detectedPose;
  ui.Image? _maskImage;
  Image? _cameraImage;
  Size _imageSize = Size.zero;

  Future<void> _selectImage() async {
    FilePickerResult? result =
        await FilePicker.platform.pickFiles(type: FileType.image);
    if (result == null || result.files.isEmpty) return;
    final path = result.files.single.path;
    if (path != null) {
      _resetState();
      setState(() {
        _selectedImage = Image.file(File(path));
      });
    }
  }

  Future<void> _detectImagePose() async {
    PngImage? pngImage = await _selectedImage?.toPngImage();
    if (pngImage == null) return;
    setState(() {
      _imageSize = Size(pngImage.width.toDouble(), pngImage.height.toDouble());
    });
    final pose = await BodyDetection.detectPose(image: pngImage);
    _handlePose(pose);
  }

  Future<void> _detectImageBodyMask() async {
    PngImage? pngImage = await _selectedImage?.toPngImage();
    if (pngImage == null) return;
    setState(() {
      _imageSize = Size(pngImage.width.toDouble(), pngImage.height.toDouble());
    });
    final mask = await BodyDetection.detectBodyMask(image: pngImage);
    _handleBodyMask(mask);
  }

  Future<void> _startCameraStream() async {
    final request = await Permission.camera.request();
    if (request.isGranted) {
      await BodyDetection.startCameraStream(
        onFrameAvailable: _handleCameraImage,
        onPoseAvailable: (pose) {
          if (!_isDetectingPose) return;
          _handlePose(pose);
        },
        onMaskAvailable: (mask) {
          if (!_isDetectingBodyMask) return;
          _handleBodyMask(mask);
        },
      );
    }
  }

  Future<void> _stopCameraStream() async {
    await BodyDetection.stopCameraStream();

    setState(() {
      _cameraImage = null;
      _imageSize = Size.zero;
    });
  }

  void _handleCameraImage(ImageResult result) {
    // Ignore callback if navigated out of the page.
    if (!mounted) return;

    // To avoid a memory leak issue.
    // https://github.com/flutter/flutter/issues/60160
    PaintingBinding.instance?.imageCache?.clear();
    PaintingBinding.instance?.imageCache?.clearLiveImages();

    final image = Image.memory(
      result.bytes,
      gaplessPlayback: true,
      fit: BoxFit.contain,
    );

    setState(() {
      _cameraImage = image;
      _imageSize = result.size;
    });
  }

  void _handlePose(Pose? pose) {
    // Ignore if navigated out of the page.
    if (!mounted) return;

    setState(() {
      _detectedPose = pose;
    });
  }

  void _handleBodyMask(BodyMask? mask) {
    // Ignore if navigated out of the page.
    if (!mounted) return;

    if (mask == null) {
      setState(() {
        _maskImage = null;
      });
      return;
    }

    final bytes = mask.buffer
        .expand(
          (it) => [0, 0, 0, (it * 255).toInt()],
        )
        .toList();
    ui.decodeImageFromPixels(Uint8List.fromList(bytes), mask.width, mask.height,
        ui.PixelFormat.rgba8888, (image) {
      setState(() {
        _maskImage = image;
      });
    });
  }

  Future<void> _toggleDetectPose() async {
    if (_isDetectingPose) {
      await BodyDetection.disablePoseDetection();
    } else {
      await BodyDetection.enablePoseDetection();
    }

    setState(() {
      _isDetectingPose = !_isDetectingPose;
      _detectedPose = null;
    });
  }

  Future<void> _toggleDetectBodyMask() async {
    if (_isDetectingBodyMask) {
      await BodyDetection.disableBodyMaskDetection();
    } else {
      await BodyDetection.enableBodyMaskDetection();
    }

    setState(() {
      _isDetectingBodyMask = !_isDetectingBodyMask;
      _maskImage = null;
    });
  }

  void _onTabEnter(int index) {
    // Camera tab
    if (index == 1) {
      _startCameraStream();
    }
  }

  void _onTabExit(int index) {
    // Camera tab
    if (index == 1) {
      _stopCameraStream();
    }
  }

  void _onTabSelectTapped(int index) {
    _onTabExit(_selectedTabIndex);
    _onTabEnter(index);

    setState(() {
      _selectedTabIndex = index;
    });
  }

  Widget? get _selectedTab => _selectedTabIndex == 0
      ? _imageDetectionView
      : _selectedTabIndex == 1
          ? _cameraDetectionView
          : null;

  void _resetState() {
    setState(() {
      _maskImage = null;
      _detectedPose = null;
      _imageSize = Size.zero;
    });
  }

  Widget get _imageDetectionView => SingleChildScrollView(
        child: Center(
          child: Column(
            children: [
              GestureDetector(
                child: ClipRect(
                  child: CustomPaint(
                    child: _selectedImage,
                    foregroundPainter: PoseMaskPainter(
                      pose: _detectedPose,
                      mask: _maskImage,
                      imageSize: _imageSize,
                    ),
                  ),
                ),
              ),
              OutlinedButton(
                onPressed: _selectImage,
                child: const Text('Select image'),
              ),
              OutlinedButton(
                onPressed: _detectImagePose,
                child: const Text('Detect pose'),
              ),
              OutlinedButton(
                onPressed: _detectImageBodyMask,
                child: const Text('Detect body mask'),
              ),
              OutlinedButton(
                onPressed: _resetState,
                child: const Text('Clear'),
              ),
            ],
          ),
        ),
      );

  Widget get _cameraDetectionView => SingleChildScrollView(
        child: Center(
          child: Column(
            children: [
              ClipRect(
                child: CustomPaint(
                  child: _cameraImage,
                  foregroundPainter: PoseMaskPainter(
                    pose: _detectedPose,
                    mask: _maskImage,
                    imageSize: _imageSize,
                  ),
                ),
              ),
              OutlinedButton(
                onPressed: _toggleDetectPose,
                child: _isDetectingPose
                    ? const Text('Turn off pose detection')
                    : const Text('Turn on pose detection'),
              ),
              OutlinedButton(
                onPressed: _toggleDetectBodyMask,
                child: _isDetectingBodyMask
                    ? const Text('Turn off body mask detection')
                    : const Text('Turn on body mask detection'),
              ),
            ],
          ),
        ),
      );

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Body Detection Plugin Example App'),
        ),
        bottomNavigationBar: BottomNavigationBar(
          items: const <BottomNavigationBarItem>[
            BottomNavigationBarItem(
              icon: Icon(Icons.image),
              label: 'Image',
            ),
            BottomNavigationBarItem(
              icon: Icon(Icons.camera),
              label: 'Camera',
            ),
          ],
          currentIndex: _selectedTabIndex,
          onTap: _onTabSelectTapped,
        ),
        body: _selectedTab,
      ),
    );
  }
}

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