Question

有没有办法获得图像的rgb矩阵表示？反之亦然？我想对原始图像执行图像屏蔽/过滤，因此需要将其应用于其rgb矩阵表示。目前正在使用此库从设备获取图像：https://pub.dartlang.org/packages/image_picker

Answer 1

https://pub.dartlang.org/packages/image提供图像转换和操作实用程序功能。

Answer 2

import 'dart:ui' as ui;
import 'package:flutter/material.dart';

// for a local iamge example
List RGBAList;
// 1. get [ImageProvider] instance
//    [ExactAssetImage] extends [AssetBundleImageProvider] extends [ImageProvider]
ExactAssetImage provider = ExactAssetImage('$local_img_uri');

// 2. get [ui.Image] by [ImageProvider]
ImageStream stream = provider.resolve(ImageConfiguration.empty);
Completer completer = Completer<ui.Image>();
ImageStreamListener listener = ImageStreamListener((frame, sync) {
    ui.Image image = frame.image;
    completer.complete(image);
    stream.removeListener(listener);
})
stream.addListener(listener);

// 3. get rgba array/list by [ui.Image]
completer.then((ui.Image image) {
    image.toByteData(format: ui.ImageByteFormat.rowRgba).then((ByteData data) {
        RGBAList = data.buffer.asUint8List().toList();
    }); 
})

将Image对象转换为rgb像素数组，然后返回Flutter

2 个答案: