Functions to load, save, share and manipulate images as bytes.

Thin wrapper of various packages related to image processing.

Note

• Web: saveAs() triggers a download.
• App: saveAs() saves to gallery.
• Web: shareAs() is not working.

This package is meant to be used in Flutter.

Usage

enum ImageFormat { jpg, png, webp }

FlutterImageUtil {
    
  // -------------------------------------------
  // SAVE
  // -------------------------------------------

  /// Shares an image via Share-dialog.
  ///
  /// Default: JPG.
  ///
  /// ### Sharing on Web
  ///
  /// Sharing on Web does not work. Use `saveToJpg()` instead.
  ///
  /// ### How to get the render box:
  /// ```
  /// if(context.mounted) {
  ///   final RenderBox? box = context.findRenderObject() as RenderBox?;
  /// }
  /// ```
  static Future<void> shareAs(
      String title,
      String message,
      Uint8List bytes,
      final RenderBox? box, {
      int quality = 100,
      Size? size,
      int? dpi,
      int rotate = 0,
      ImageFormat format = ImageFormat.jpg,
  });

  /// Web: Downloads the file via Browser.
  ///
  /// Android: Saves in `album`. If album is NULL 
  /// its name will be the name of the image.
  ///
  /// Returns the String-path of the created File.
  ///
  /// Default: JPG.
  static Future<String?> saveAs(
      Uint8List bytes,
      String name, {
      String? album,
      int quality = 100,
      Size? size,
      int? dpi,
      int rotate = 0,
      ImageFormat format = ImageFormat.jpg,
  });

  // -------------------------------------------
  // LOAD
  // -------------------------------------------

  /// Loads an image from the given [url].
  ///
  /// Keep in mind to adjust the server CORS settings.
  static Future<Uint8List> loadFromWeb(
    double widthMax, double heightMax, int quality, url);

  /// Loads an image from the local gallery.
  static Future<Uint8List> loadFromGallery(
    double widthMax, double heightMax, int quality);

  /// Loads an image using the local camera.
  static Future<Uint8List> loadFromCamera(
    double widthMax, double heightMax, int quality);

  // -------------------------------------------
  // GENERAL
  // -------------------------------------------

  /// Compresses `bytes` to PNG.
  static Future<Uint8List> compressToPng(
    Uint8List pngBytes, double width, double height,
    {int quality = 100});

  /// Compresses `bytes` to JPG.
  static Future<Uint8List> compressToJpg(
    Uint8List pngBytes, double width, double height,
    {int quality = 100});

  /// Compresses `bytes` to WEBP.
  ///
  /// Only on Android.
  static Future<Uint8List> compressToWebp(
    Uint8List pngBytes, double width, double height,
    [int quality = 100]);

  /// Sets the DPI in EXIF.
  static Future<Uint8List> setDpi(Uint8List imageBytes, int dpi);

  /// Returns the `Size` of the image.
  static Size getSize(Uint8List bytes);


  /// Rotates the image.
  static Future<Uint8List> rotate(Uint8List bytes, int rotate,
      {ImageFormat format = ImageFormat.jpg})
}