converting image to base64 in flutter - image

Question

I take a picture with phone's camera, then resize it and convert it to base64 string. However, after those manipulations, base64 string that I get doesn't seem to be valid.
I try to convert it back to image on this website https://codebeautify.org/base64-to-image-converter . After I click generate image, nothing happens, however sample on their website works. Tried on the other websites and still no luck.
My code:
import 'package:image/image.dart' as img;
import 'package:image_picker/image_picker.dart';
File _photo;
String photoBase64;
Future getImage(ImageSource source) async {
var photo = await ImagePicker.pickImage(source: source);
img.Image image = img.decodeImage(photo.readAsBytesSync());
img.Image imageResized = img.copyResize(image, width: 120);
setState(() {
_photo = photo;
List<int> imageBytes = imageResized.getBytes();
photoBase64 = base64Encode(imageBytes);
});
}
I tried base64UrlEncode() too, however the issue still remains. String I am trying to convert back to image is photoBase64. My goal is to send it in a body of a POST request later. What exactly am I doing wrong here?
Thank you

Answer 1

You can copy paste run full code below
You can use package https://pub.dev/packages/flutter_native_image to get resized image
imageResized = await FlutterNativeImage.compressImage(photo.path,
quality: 100, targetWidth: 120, targetHeight: 120);
...
List<int> imageBytes = imageResized.readAsBytesSync();
working demo
full code
import 'package:flutter/material.dart';
import 'package:image/image.dart' as img;
import 'package:image_picker/image_picker.dart';
import 'dart:io';
import 'dart:convert';
import 'package:flutter_native_image/flutter_native_image.dart';
void main() => runApp(MyApp());
File _photo;
String photoBase64;
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
File imageResized;
Future getImage(ImageSource source) async {
var photo = await ImagePicker.pickImage(source: source);
imageResized = await FlutterNativeImage.compressImage(photo.path,
quality: 100, targetWidth: 120, targetHeight: 120);
setState(() {
_photo = photo;
List<int> imageBytes = imageResized.readAsBytesSync();
photoBase64 = base64Encode(imageBytes);
print(photoBase64);
});
}
void _incrementCounter() {
getImage(ImageSource.camera);
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
imageResized == null ? Container() : Image.file(imageResized),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}

Answer 2

my solution
Future getImage() async {
pickedFile =
await _picker.getImage(source: ImageSource.gallery, imageQuality: 50);
setState(() {
if (pickedFile != null) {
file = File(pickedFile!.path);
final bytes =
file!.readAsBytesSync();
img64 = base64Encode(bytes);
} else {
print('No image selected.');
}
});
}