flutter_image_filters - Dart API docs

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

LUT

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

LUT

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

Sample results

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