flutter_image_filters: A GLSL repository from icc-tips

A flutter package for iOS and Android for applying OpenGL filters to image.

Usage

How to generate and use a bunch of filters

How to add custom filters

Export processed image

final texture = await TextureSource.fromAsset('demo.jpeg');
final configuration = BrightnessShaderConfiguration();
configuration.brightness = 0.5;
final image = await configuration.export(texture, texture.size);

Pipeline export

In case you see performance issues, look on how to generate and use bunch of filters

final texture = await TextureSource.fromAsset('demo.jpeg');
final brConfig = BrightnessShaderConfiguration();
brConfig.brightness = 0.5;

final stConfig = SaturationShaderConfiguration();
stConfig.saturation = 0.5;

final configuration = GroupShaderConfiguration();
configuration.add(brConfig);
configuration.add(stConfig);
final result = await configuration.export(texture, texture.size);

LookupTable sample

final texture = await TextureSource.fromAsset('demo.jpeg');
final configuration = SquareLookupTableShaderConfiguration();
await configuration.setLutAsset('lookup_amatorka.png');
final image = await configuration.export(texture, texture.size);

LookupTable HALD sample

final texture = await TextureSource.fromAsset('demo.jpeg');
final configuration = HALDLookupTableShaderConfiguration();
await configuration.setLutAsset('lookup_hald.png');
final image = await configuration.export(texture, texture.size);

ImageShaderPreview example

import 'package:flutter_image_filters/flutter_image_filters.dart';

class PreviewPage extends StatefulWidget {
  const PreviewPage({Key? key}) : super(key: key);

  @override
  State<PreviewPage> createState() => _PreviewPageState();
}

class _PreviewPageState extends State<PreviewPage> {
  late TextureSource texture;
  late BrightnessShaderConfiguration configuration;
  bool textureLoaded = false;

  @override
  void initState() {
    super.initState();
    configuration = BrightnessShaderConfiguration();
    configuration.brightness = 0.5;
    TextureSource.fromAsset('demo.jpeg')
        .then((value) => texture = value)
        .whenComplete(
          () => setState(() {
            textureLoaded = true;
          }),
        );
  }

  @override
  Widget build(BuildContext context) {
    return textureLoaded
        ? ImageShaderPreview(
            texture: texture,
            configuration: configuration,
          )
        : const Offstage();
  }
}

PipelineImageShaderPreview example

class PreviewPage extends StatefulWidget {
  const PreviewPage({Key? key}) : super(key: key);

  @override
  State<PreviewPage> createState() => _PreviewPageState();
}

class _PreviewPageState extends State<PreviewPage> {
  late TextureSource texture;
  late GroupShaderConfiguration configuration;
  bool textureLoaded = false;

  @override
  void initState() {
    super.initState();
    configuration = GroupShaderConfiguration();
    configuration.add(BrightnessShaderConfiguration()..brightness = 0.5);
    configuration.add(SaturationShaderConfiguration()..saturation = 0.5);
    TextureSource.fromAsset('demo.jpeg')
        .then((value) => texture = value)
        .whenComplete(
          () => setState(() {
        textureLoaded = true;
      }),
    );
  }

  @override
  Widget build(BuildContext context) {
    return textureLoaded
        ? PipelineImageShaderPreview(
      texture: texture,
      configuration: configuration,
    )
        : const Offstage();
  }
}

Divided preview sample

import 'package:before_after_image_slider_nullsafty/before_after_image_slider_nullsafty.dart';
import 'package:flutter_image_filters/flutter_image_filters.dart';

class PreviewPage extends StatefulWidget {
  const PreviewPage({Key? key}) : super(key: key);

  @override
  State<PreviewPage> createState() => _PreviewPageState();
}

class _PreviewPageState extends State<PreviewPage> {
  late TextureSource texture;
  late BrightnessShaderConfiguration configuration;
  bool textureLoaded = false;

  @override
  void initState() {
    super.initState();
    configuration = BrightnessShaderConfiguration();
    configuration.brightness = 0.5;
    TextureSource.fromAsset('demo.jpeg')
        .then((value) => texture = value)
        .whenComplete(
          () => setState(() {
            textureLoaded = true;
          }),
        );
  }

  @override
  Widget build(BuildContext context) {
    return textureLoaded
        ? BeforeAfter(
            thumbRadius: 0.0,
            thumbColor: Colors.transparent,
            beforeImage: ImageShaderPreview(
              texture: texture,
              configuration: NoneShaderConfiguration(),
            ),
            afterImage: ImageShaderPreview(
              texture: texture,
              configuration: configuration,
            ),
          )
        : const Offstage();
  }
}

Export & save processed image

import 'package:image/image.dart' as img;
import 'package:path_provider/path_provider.dart';



final texture = await TextureSource.fromAsset('demo.jpeg');
final configuration = BrightnessShaderConfiguration();
configuration.brightness = 0.5;
final image = await configuration.export(texture, texture.size);

final directory = await getTemporaryDirectory();
final output =
File('${directory.path}/result.jpeg');
final bytes = await image.toByteData();
final persistedImage = img.Image.fromBytes(
  image.width,
  image.height,
  bytes!.buffer.asUint8List(),
);
img.JpegEncoder encoder = img.JpegEncoder();
final data = encoder.encodeImage(persistedImage);
await output.writeAsBytes(data);

Additional information

Support status of GPUImage for iOS and GPUImage for Android shaders

Status	Name
✅	Brightness
✅	Bulge Distortion
✅	CGA Colorspace
✅	Color Invert
✅	Color Matrix
✅	Contrast
✅	Crosshatch
✅	Exposure
✅	False Color
✅	Gamma
✅	Glass Sphere
✅	Grayscale
✅	Halftone
✅	Haze
✅	Highlight Shadow
✅	Hue
✅	Lookup Table
✅	Luminance
✅	Luminance Threshold
✅	Monochrome
✅	Opacity
✅	Pixelation
✅	Posterize
✅	RGB
✅	Saturation
✅	Solarize
✅	Swirl
✅	Vibrance
✅	Vignette
✅	White Balance
✅	Zoom Blur