我正在尝试将面孔与AWS rekognition API进行比较。但不知何故，我一直都在遇到“断管”错误。 aws键和照片没有问题。我正试图从http.post获取更多信息，但是不幸的是，它只说了“断管”，没有提供任何细节。
场景；
我也将图像质量更改为最低，但这没有帮助。
Main.dart代码
import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:camera/camera.dart';
import 'testa.dart';
import 'package:path_provider/path_provider.dart';
List<CameraDescription> cameras;
Future<void> main() async {
cameras = await availableCameras();
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
CameraController controller;
@override
void initState() {
super.initState();
controller = CameraController(cameras[0], ResolutionPreset.low);
controller.initialize().then((_) {
if (!mounted) {
return;
}
setState(() {});
});
}
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
Future<String> _checkImage(String filePath, String secondPath) async {
File sourceImagefile, targetImagefile; //load source and target images in those File objects
String accessKey, secretKey, region ; //load your aws account info in those variables
print(filePath);
print(secondPath);
targetImagefile = File(filePath);
sourceImagefile = File(secondPath);
print(targetImagefile.existsSync());
print(sourceImagefile.existsSync());
accessKey = '';
secretKey = '';
region = 'eu-west-1';
RekognitionHandler rekognition = new RekognitionHandler(accessKey, secretKey, region);
String labelsArray = await rekognition.compareFaces(sourceImagefile, targetImagefile);
return labelsArray;
}
Widget cameraPart() {
if (!controller.value.isInitialized) {
return Container();
}
return AspectRatio(
aspectRatio:
controller.value.aspectRatio,
child: CameraPreview(controller));
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: cameraPart(),
floatingActionButton: FloatingActionButton(
onPressed: takePhoto,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
Future<String> get360PhotoFolder() async {
final Directory appFolder = await getAppFolder();
final String dirPath = '${appFolder.path}/photos360';
await Directory(dirPath).create(recursive: true);
return dirPath;
}
String firstPath = '';
String secondPath = '';
Future<bool> takePhoto() async {
final String dirPath = await get360PhotoFolder();
final String filePath = '$dirPath/${timestamp()}_test.jpg';
try {
debugPrint('photo taken - $filePath');
await controller.takePicture(filePath);
setState(() {
if (firstPath == '') {
print('a');
firstPath = filePath;
}else if (secondPath == '') {
print('b');
secondPath = filePath;
_checkImage(firstPath, secondPath).then((value) {
print(value);
}).catchError((error) {
print(error);
});
firstPath = '';
secondPath = '';
}
});
} on CameraException catch (e) {
print([e.code, e.description]);
return true;
}
return false;
}
String timestamp() => DateTime.now().millisecondsSinceEpoch.toString();
Future<Directory> getAppFolder() async =>
await getApplicationDocumentsDirectory();
}
AWS识别代码
import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'package:intl/intl.dart';
import 'testb.dart';
class RekognitionHandler {
final String _accessKey, _secretKey, _region;
RekognitionHandler(this._accessKey, this._secretKey, this._region);
Future<String> _rekognitionHttp(String amzTarget, String body) async {
String endpoint = "https://rekognition.$_region.amazonaws.com/";
String host = "rekognition.$_region.amazonaws.com";
String httpMethod = "POST";
String service = "rekognition";
var now = new DateTime.now().toUtc();
var amzFormatter = new DateFormat("yyyyMMdd'T'HHmmss'Z'");
String amzDate =
amzFormatter.format(now); // format should be '20170104T233405Z"
var dateFormatter = new DateFormat('yyyyMMdd');
String dateStamp = dateFormatter.format(
now); // Date w/o time, used in credential scope. format should be "20170104"
int bodyLength = body.length;
String queryStringParamters = "";
Map<String, String> headerParamters = {
"content-length": bodyLength.toString(),
"content-type": "application/x-amz-json-1.1",
"host": host,
"x-amz-date": amzDate,
"x-amz-target": amzTarget
};
String signature = Signature.generateSignature(
endpoint,
service,
_region,
_secretKey,
httpMethod,
now,
queryStringParamters,
headerParamters,
body);
String authorization =
"AWS4-HMAC-SHA256 Credential=$_accessKey/$dateStamp/$_region/$service/aws4_request, SignedHeaders=content-length;content-type;host;x-amz-date;x-amz-target, Signature=$signature";
headerParamters.putIfAbsent('Authorization', () => authorization);
//String labelsArray = "";
StringBuffer builder = new StringBuffer();
try {
HttpClient httpClient = new HttpClient();
httpClient.connectionTimeout = Duration(minutes: 10);
HttpClientRequest request = await httpClient.postUrl(Uri.parse(endpoint));
request.headers.set('content-length', headerParamters['content-length']);
request.headers.set('content-type', headerParamters['content-type']);
request.headers.set('host', headerParamters['host']);
request.headers.set('x-amz-date', headerParamters['x-amz-date']);
request.headers.set('x-amz-target', headerParamters['x-amz-target']);
request.headers.set('Authorization', headerParamters['Authorization']);
request.write(body);
HttpClientResponse response = await request.close();
await for (String a in response.transform(utf8.decoder)) {
builder.write(a);
}
} catch (e) {
print(e);
}
return Future.value(builder.toString());
}
Future<String> compareFaces(
File sourceImagefile, File targetImagefile) async {
try {
List<int> sourceImageBytes = sourceImagefile.readAsBytesSync();
String base64SourceImage = base64Encode(sourceImageBytes);
List<int> targetImageBytes = targetImagefile.readAsBytesSync();
String base64TargetImage = base64Encode(targetImageBytes);
String body =
'{"SourceImage":{"Bytes": "$base64SourceImage"},"TargetImage":{"Bytes": "$base64TargetImage"}}';
String amzTarget = "RekognitionService.CompareFaces";
String response = await _rekognitionHttp(amzTarget, body);
return response;
} catch (e) {
print(e);
return "{}";
}
}
}