PaletteGenerator class

A class to extract prominent colors from an image for use as user interface colors.

To create a new PaletteGenerator, use the asynchronous PaletteGenerator.fromImage static function.

A number of color paletteColors with different profiles are chosen from the image:

You may add your own target palette color types by supplying them to the targets parameter for PaletteGenerator.fromImage.

In addition, the population-sorted list of discovered colors is available, and a paletteColors list providing contrasting title text and body text colors for each palette color.

The palette is created using a color quantizer based on the Median-cut algorithm, but optimized for picking out distinct colors rather than representative colors.

The color space is represented as a 3-dimensional cube with each dimension being one component of an RGB image. The cube is then repeatedly divided until the color space is reduced to the requested number of colors. An average color is then generated from each cube.

What makes this different from a median-cut algorithm is that median-cut divides cubes so that all of the cubes have roughly the same population, where the quantizer that is used to create the palette divides cubes based on their color volume. This means that the color space is divided into distinct colors, rather than representative colors.

Constructors

PaletteGenerator.fromColors(List<PaletteColor> paletteColors, {List<PaletteTarget> targets = const <PaletteTarget>[]}): Create a PaletteGenerator from a set of paletteColors and targets.

Properties

colors → Iterable<Color>: Returns a list of colors in the paletteColors, sorted from most dominant to least dominant color.
no setter
darkMutedColor → PaletteColor?: Returns a muted and dark color from the palette. Might be null if an appropriate target color could not be found.
no setter
darkVibrantColor → PaletteColor?: Returns a dark and vibrant color from the palette. Might be null if an appropriate target color could not be found.
no setter
dominantColor → PaletteColor?: The dominant color (the color with the largest population).
no setter
hashCode → int: The hash code for this object.
no setterinherited
lightMutedColor → PaletteColor?: Returns a muted and light color from the palette. Might be null if an appropriate target color could not be found.
no setter
lightVibrantColor → PaletteColor?: Returns a light and vibrant color from the palette. Might be null if an appropriate target color could not be found.
no setter
mutedColor → PaletteColor?: Returns a muted color from the palette. Might be null if an appropriate target color could not be found.
no setter
paletteColors → List<PaletteColor>: The list of PaletteColors that make up the palette, sorted from most dominant color to least dominant color.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
selectedSwatches → Map<PaletteTarget, PaletteColor>: Provides a map of the selected paletteColors for each target in targets.
final
targets → List<PaletteTarget>: The list of targets that the palette uses for custom color selection.
final
vibrantColor → PaletteColor?: Returns a vibrant color from the palette. Might be null if an appropriate target color could not be found.
no setter

Methods

debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
override
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringShort() → String: A brief description of this object, usually just the runtimeType and the hashCode.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

fromByteData(EncodedImage encodedImage, {Rect? region, int maximumColorCount = _defaultCalculateNumberColors, List<PaletteFilter> filters = const <PaletteFilter>[avoidRedBlackWhitePaletteFilter], List<PaletteTarget> targets = const <PaletteTarget>[]}) → Future<PaletteGenerator>: Create a PaletteGenerator asynchronously from encoded image ByteData, width, and height. These parameters are packed in EncodedImage.
fromImage(Image image, {Rect? region, int maximumColorCount = _defaultCalculateNumberColors, List<PaletteFilter> filters = const <PaletteFilter>[avoidRedBlackWhitePaletteFilter], List<PaletteTarget> targets = const <PaletteTarget>[]}) → Future<PaletteGenerator>: Create a PaletteGenerator from an dart:ui.Image asynchronously.
fromImageProvider(ImageProvider<Object> imageProvider, {Size? size, Rect? region, int maximumColorCount = _defaultCalculateNumberColors, List<PaletteFilter> filters = const <PaletteFilter>[avoidRedBlackWhitePaletteFilter], List<PaletteTarget> targets = const <PaletteTarget>[], Duration timeout = const Duration(seconds: 15)}) → Future<PaletteGenerator>: Create a PaletteGenerator from an ImageProvider, like FileImage, or AssetImage, asynchronously.