Workaround for Image widget not applying the filter quality unless you force it to change size via the "fit" operation

main.dart

import 'dart:typed_data';
import 'dart:ui' as ui;

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

void main() {
  runApp(ImageTestApp());
}

class ImageTestApp extends StatefulWidget {
  @override
  State createState() => ImageTestAppState();
}

class ImageTestAppState extends State<ImageTestApp> {
  final isCanvasKit = const bool.fromEnvironment('FLUTTER_WEB_USE_SKIA', defaultValue: false);
  bool padTweak = false;
  bool boxTweak = false;
  Map<String, ui.Image> uiImages = {};

  @override
  void initState() {
    super.initState();
    _loadImages();
  }

  Future<void> _loadImages() async {
    await _loadImage('images/sample.png');
    await _loadImage('images/sample2.png');
    await _loadImage('images/sample3.png');
    setState(() async {
    });
  }

  Future<void> _loadImage(String imageFile) async {
    ByteData bd = await rootBundle.load(imageFile);
    final Uint8List bytes = Uint8List.view(bd.buffer);
    final ui.Codec codec = await ui.instantiateImageCodec(bytes);
    final ui.Image image = (await codec.getNextFrame()).image;
    uiImages[imageFile] = image;
  }

  Widget tweakedImage(ImageProvider provider, FilterQuality quality, Size size) {
    Image image = Image(
      image: provider,
      filterQuality: quality,
      fit: BoxFit.fill,
      width: padTweak ? size.width + 0.001 : null,
      height: padTweak ? size.height + 0.001 : null,
    );
    if (!boxTweak) return image;
    return SizedBox(
      width: size.width + 0.001,
      height: size.height + 0.001,
      child: image,
    );
  }

  Widget wrap(String imageFile, Size size) {
    ImageProvider provider = AssetImage(imageFile);
    return Row(
      children: <Widget>[
        tweakedImage(provider, FilterQuality.none, size),
        tweakedImage(provider, FilterQuality.low, size),
        tweakedImage(provider, FilterQuality.high, size),
        if (uiImages[imageFile] != null)
          CustomPaint(
            painter: _ImagePainter(uiImages[imageFile], FilterQuality.none),
            child: SizedBox(width: size.width, height: size.height,),
          ),
        if (uiImages[imageFile] != null)
          CustomPaint(
            painter: _ImagePainter(uiImages[imageFile], FilterQuality.low),
            child: SizedBox(width: size.width, height: size.height,),
          ),
        if (uiImages[imageFile] != null)
          CustomPaint(
            painter: _ImagePainter(uiImages[imageFile], FilterQuality.high),
            child: SizedBox(width: size.width, height: size.height,),
          ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Container(
          child: Container(
            padding: const EdgeInsets.all(8.0),
            width: double.infinity,
            child: Column(
              crossAxisAlignment: isCanvasKit ? CrossAxisAlignment.start : CrossAxisAlignment.end,
              children: <Widget>[
                Text(isCanvasKit ? 'CanvasKit' : 'HTML'),
                Row(
                  children: [
                    Text('Pad Image size tweak: '),
                    Checkbox(value: padTweak, onChanged: (value) => setState(() { padTweak = value; }),),
                    SizedBox(width: 20),
                    Text('SizedBox tweak: '),
                    Checkbox(value: boxTweak, onChanged: (value) => setState(() { boxTweak = value; }),),
                  ],
                ),
                SizedBox(height: 20),
                wrap('images/sample2.png', Size(200, 200)),
                wrap('images/sample.png',  Size(100, 100)),
                wrap('images/sample3.png', Size(60, 60)),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _ImagePainter extends CustomPainter {
  _ImagePainter(this.image, this.filterQuality);

  final ui.Image image;
  final FilterQuality filterQuality;

  @override
  void paint(Canvas canvas, Size size) {
    canvas.drawImage(image, Offset.zero, Paint()..filterQuality = filterQuality);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => true;
}