flutter_image_compress 0.2.2

compress image with native code(objc kotlin), it's faster. This library can work on android/ios.

example/lib/main.dart

import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:io';

import 'package:flutter/services.dart';
import 'package:flutter_image_compress/flutter_image_compress.dart';

import 'package:path_provider/path_provider.dart' as path_provider;
// import 'package:image_picker/image_picker.dart';

void main() => runApp(new MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  void initState() {
    super.initState();
  }

  // Platform messages are asynchronous, so we initialize in an async method.
  Future<void> compress() async {
    var img = AssetImage("img/img.jpg");
    print("pre compress");
    var config = new ImageConfiguration();

    AssetBundleImageKey key = await img.obtainKey(config);
    final ByteData data = await key.bundle.load(key.name);

    var beforeCompress = data.lengthInBytes;
    print("beforeCompress = $beforeCompress");

    var result = await FlutterImageCompress.compressWithList(data.buffer.asUint8List());

    print("after = ${result?.length ?? 0}");
  }

  ImageProvider provider;

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          title: const Text('Plugin example app'),
        ),
        body: new Center(
          child: Column(
            children: <Widget>[
              AspectRatio(
                child: Image(
                  image: provider ?? AssetImage("img/img.jpg"),
                  width: double.infinity,
                  fit: BoxFit.contain,
                ),
                aspectRatio: 1 / 1,
              ),
              FlatButton(
                child: Text('CompressFile and rotate 180'),
                onPressed: _testCompressFile,
              ),
              FlatButton(
                child: Text('CompressAndGetFile and rotate 90'),
                onPressed: getFileImage,
              ),
              FlatButton(
                child: Text('CompressAsset and rotate 135'),
                onPressed: () => testCompressAsset("img/img.jpg"),
              ),
              FlatButton(
                child: Text('CompressList and rotate 270'),
                onPressed: compressListExample,
              ),
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          child: Icon(Icons.computer),
          onPressed: () => setState(() => this.provider = null),
          tooltip: "show origin asset",
        ),
      ),
    );
  }

  Future<Directory> getTemporaryDirectory() async {
    return Directory.systemTemp;
  }

  void _testCompressFile() async {
    var img = AssetImage("img/img.jpg");
    print("pre compress");
    var config = new ImageConfiguration();

    AssetBundleImageKey key = await img.obtainKey(config);
    final ByteData data = await key.bundle.load(key.name);
    var dir = await path_provider.getTemporaryDirectory();
    print('dir = $dir');

    File file = File("${dir.absolute.path}/test.png");
    file.writeAsBytesSync(data.buffer.asUint8List());

    List<int> list = await testCompressFile(file);
    ImageProvider provider = MemoryImage(Uint8List.fromList(list));
    this.provider = provider;
    setState(() {});
  }

  void getFileImage() async {
    var img = AssetImage("img/img.jpg");
    print("pre compress");
    var config = new ImageConfiguration();

    AssetBundleImageKey key = await img.obtainKey(config);
    final ByteData data = await key.bundle.load(key.name);
    var dir = await path_provider.getTemporaryDirectory();

    File file = File("${dir.absolute.path}/test.png");
    file.writeAsBytesSync(data.buffer.asUint8List());

    var targetPath = dir.absolute.path + "/temp.png";
    var imgFile = await testCompressAndGetFile(file, targetPath);

    provider = FileImage(imgFile);
    setState(() {});
  }

  Future<List<int>> testCompressFile(File file) async {
    print("testCompressFile");
    var result = await FlutterImageCompress.compressWithFile(
      file.absolute.path,
      minWidth: 2300,
      minHeight: 1500,
      quality: 94,
      rotate: 180,
    );
    print(file.lengthSync());
    print(result.length);
    return result;
  }

  Future<File> testCompressAndGetFile(File file, String targetPath) async {
    print("testCompressAndGetFile");
    var result = await FlutterImageCompress.compressAndGetFile(
      file.absolute.path,
      targetPath,
      quality: 90,
      minWidth: 1024,
      minHeight: 1024,
      rotate: 90,
    );

    print(file.lengthSync());
    print(result.lengthSync());

    return result;
  }

  Future testCompressAsset(String assetName) async {
    print("testCompressAsset");
    var list = await FlutterImageCompress.compressAssetImage(
      assetName,
      minHeight: 1920,
      minWidth: 1080,
      quality: 96,
      rotate: 135,
    );

    this.provider = MemoryImage(Uint8List.fromList(list));
    setState(() {});
  }

  Future compressListExample() async {
    var img = AssetImage("img/img.jpg");
    print("pre compress");
    var config = new ImageConfiguration();

    AssetBundleImageKey key = await img.obtainKey(config);
    final ByteData data = await key.bundle.load(key.name);
    var list = List<int>.from(data.buffer.asUint8List());

    // print(list);

    list = await testComporessList(list);

    var memory = Uint8List.fromList(list);
    setState(() {
      this.provider = MemoryImage(memory);
    });
  }

  Future<List<int>> testComporessList(List<int> list) async {
    var result = await FlutterImageCompress.compressWithList(
      list,
      minHeight: 1920,
      minWidth: 1080,
      quality: 96,
      rotate: 270,
    );
    print(list.length);
    print(result.length);
    return result;
  }

  void writeToFile(List<int> list, String filePath) {
    var file = File(filePath);
    file.writeAsBytes(list, flush: true, mode: FileMode.write);
  }
}