Summary: Methods | Inherited Methods

ColorUtils

Kotlin |Java

public final class ColorUtils
extends Object

java.lang.Object
↳	androidx.core.graphics.ColorUtils

A set of color-related utility methods, building upon those available in Color.

Summary

Public methods
`static int`	`HSLToColor(float[] hsl)` Convert HSL (hue-saturation-lightness) components to a RGB color.
`static int`	`LABToColor(double l, double a, double b)` Converts a color from CIE Lab to its RGB representation.
`static void`	`LABToXYZ(double l, double a, double b, double[] outXyz)` Converts a color from CIE Lab to CIE XYZ representation.
`static void`	`RGBToHSL(int r, int g, int b, float[] outHsl)` Convert RGB components to HSL (hue-saturation-lightness).
`static void`	`RGBToLAB(int r, int g, int b, double[] outLab)` Convert RGB components to its CIE Lab representative components.
`static void`	`RGBToXYZ(int r, int g, int b, double[] outXyz)` Convert RGB components to its CIE XYZ representative components.
`static int`	`XYZToColor(double x, double y, double z)` Converts a color from CIE XYZ to its RGB representation.
`static void`	`XYZToLAB(double x, double y, double z, double[] outLab)` Converts a color from CIE XYZ to CIE Lab representation.
`static int`	`blendARGB(int color1, int color2, float ratio)` Blend between two ARGB colors using the given ratio.
`static void`	`blendHSL(float[] hsl1, float[] hsl2, float ratio, float[] outResult)` Blend between `hsl1` and `hsl2` using the given ratio.
`static void`	`blendLAB(double[] lab1, double[] lab2, double ratio, double[] outResult)` Blend between two CIE-LAB colors using the given ratio.
`static double`	`calculateContrast(int foreground, int background)` Returns the contrast ratio between `foreground` and `background`.
`static double`	`calculateLuminance(int color)` Returns the luminance of a color as a float between `0.0` and `1.0`.
`static int`	`calculateMinimumAlpha(int foreground, int background, float minContrastRatio)` Calculates the minimum alpha value which can be applied to `foreground` so that would have a contrast value of at least `minContrastRatio` when compared to `background`.
`static void`	`colorToHSL(int color, float[] outHsl)` Convert the ARGB color to its HSL (hue-saturation-lightness) components.
`static void`	`colorToLAB(int color, double[] outLab)` Convert the ARGB color to its CIE Lab representative components.
`static void`	`colorToXYZ(int color, double[] outXyz)` Convert the ARGB color to its CIE XYZ representative components.
`static Color`	`compositeColors(Color foreground, Color background)` Composites two translucent colors together.
`static int`	`compositeColors(int foreground, int background)` Composite two potentially translucent colors over each other and returns the result.
`static double`	`distanceEuclidean(double[] labX, double[] labY)` Returns the euclidean distance between two LAB colors.
`static int`	`setAlphaComponent(int color, int alpha)` Set the alpha component of `color` to be `alpha`.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()`
`boolean`	`equals(Object arg0)`
`void`	`finalize()`
`final Class<?>`	`getClass()`
`int`	`hashCode()`
`final void`	`notify()`
`final void`	`notifyAll()`
`String`	`toString()`
`final void`	`wait(long arg0, int arg1)`
`final void`	`wait(long arg0)`
`final void`	`wait()`

Public methods

HSLToColor

public static int HSLToColor (float[] hsl)

Convert HSL (hue-saturation-lightness) components to a RGB color.

hsl[0] is Hue [0 .. 360)
hsl[1] is Saturation [0...1]
hsl[2] is Lightness [0...1]

If hsv values are out of range, they are pinned.

Parameters
`hsl`	`float`: 3-element array which holds the input HSL components

Returns
`int`	the resulting RGB color

LABToColor

public static int LABToColor (double l, 
                double a, 
                double b)

Converts a color from CIE Lab to its RGB representation.

Parameters
`l`	`double`: L component value [0...100] Value is between 0.0 and 100.0 inclusive.
`a`	`double`: A component value [-128...127] Value is between -128.0 and 127.0 inclusive.
`b`	`double`: B component value [-128...127] Value is between -128.0 and 127.0 inclusive.

Returns
`int`	int containing the RGB representation

LABToXYZ

public static void LABToXYZ (double l, 
                double a, 
                double b, 
                double[] outXyz)

Converts a color from CIE Lab to CIE XYZ representation.

The resulting XYZ representation will use the D65 illuminant and the CIE 2° Standard Observer (1931).

outXyz[0] is X [0 ...95.047)
outXyz[1] is Y [0...100)
outXyz[2] is Z [0...108.883)

Parameters
`l`	`double`: L component value [0...100) Value is between 0.0 and 100.0 inclusive.
`a`	`double`: A component value [-128...127) Value is between -128.0 and 127.0 inclusive.
`b`	`double`: B component value [-128...127) Value is between -128.0 and 127.0 inclusive.
`outXyz`	`double`: 3-element array which holds the resulting XYZ components

RGBToHSL

public static void RGBToHSL (int r, 
                int g, 
                int b, 
                float[] outHsl)

Convert RGB components to HSL (hue-saturation-lightness).

outHsl[0] is Hue [0 .. 360)
outHsl[1] is Saturation [0...1]
outHsl[2] is Lightness [0...1]

Parameters
`r`	`int`: red component value [0..255] Value is 255 or less.
`g`	`int`: green component value [0..255] Value is 255 or less.
`b`	`int`: blue component value [0..255] Value is 255 or less.
`outHsl`	`float`: 3-element array which holds the resulting HSL components

RGBToLAB

public static void RGBToLAB (int r, 
                int g, 
                int b, 
                double[] outLab)

Convert RGB components to its CIE Lab representative components.

outLab[0] is L [0 ...1)
outLab[1] is a [-128...127)
outLab[2] is b [-128...127)

Parameters
`r`	`int`: red component value [0..255] Value is 255 or less.
`g`	`int`: green component value [0..255] Value is 255 or less.
`b`	`int`: blue component value [0..255] Value is 255 or less.
`outLab`	`double`: 3-element array which holds the resulting LAB components

RGBToXYZ

public static void RGBToXYZ (int r, 
                int g, 
                int b, 
                double[] outXyz)

Convert RGB components to its CIE XYZ representative components.

The resulting XYZ representation will use the D65 illuminant and the CIE 2° Standard Observer (1931).

outXyz[0] is X [0 ...95.047)
outXyz[1] is Y [0...100)
outXyz[2] is Z [0...108.883)

Parameters
`r`	`int`: red component value [0..255] Value is 255 or less.
`g`	`int`: green component value [0..255] Value is 255 or less.
`b`	`int`: blue component value [0..255] Value is 255 or less.
`outXyz`	`double`: 3-element array which holds the resulting XYZ components

XYZToColor

public static int XYZToColor (double x, 
                double y, 
                double z)

Converts a color from CIE XYZ to its RGB representation.

This method expects the XYZ representation to use the D65 illuminant and the CIE 2° Standard Observer (1931).

Parameters
`x`	`double`: X component value [0...95.047) Value is between 0.0 and 95.047 inclusive.
`y`	`double`: Y component value [0...100) Value is between 0.0 and 100.0 inclusive.
`z`	`double`: Z component value [0...108.883) Value is between 0.0 and 108.883 inclusive.

Returns
`int`	int containing the RGB representation

XYZToLAB

public static void XYZToLAB (double x, 
                double y, 
                double z, 
                double[] outLab)

Converts a color from CIE XYZ to CIE Lab representation.

This method expects the XYZ representation to use the D65 illuminant and the CIE 2° Standard Observer (1931).

outLab[0] is L [0 ...1)
outLab[1] is a [-128...127)
outLab[2] is b [-128...127)

Parameters
`x`	`double`: X component value [0...95.047) Value is between 0.0 and 95.047 inclusive.
`y`	`double`: Y component value [0...100) Value is between 0.0 and 100.0 inclusive.
`z`	`double`: Z component value [0...108.883) Value is between 0.0 and 108.883 inclusive.
`outLab`	`double`: 3-element array which holds the resulting Lab components

blendARGB

public static int blendARGB (int color1, 
                int color2, 
                float ratio)

Blend between two ARGB colors using the given ratio.

A blend ratio of 0.0 will result in color1, 0.5 will give an even blend, 1.0 will result in color2.

Parameters
`color1`	`int`: the first ARGB color
`color2`	`int`: the second ARGB color
`ratio`	`float`: the blend ratio of `color1` to `color2` Value is between 0.0 and 1.0 inclusive.

Returns
`int`

blendHSL

public static void blendHSL (float[] hsl1, 
                float[] hsl2, 
                float ratio, 
                float[] outResult)

Blend between hsl1 and hsl2 using the given ratio. This will interpolate the hue using the shortest angle.

A blend ratio of 0.0 will result in hsl1, 0.5 will give an even blend, 1.0 will result in hsl2.

Parameters
`hsl1`	`float`: 3-element array which holds the first HSL color
`hsl2`	`float`: 3-element array which holds the second HSL color
`ratio`	`float`: the blend ratio of `hsl1` to `hsl2` Value is between 0.0 and 1.0 inclusive.
`outResult`	`float`: 3-element array which holds the resulting HSL components

blendLAB

public static void blendLAB (double[] lab1, 
                double[] lab2, 
                double ratio, 
                double[] outResult)

Blend between two CIE-LAB colors using the given ratio.

A blend ratio of 0.0 will result in lab1, 0.5 will give an even blend, 1.0 will result in lab2.

Parameters
`lab1`	`double`: 3-element array which holds the first LAB color
`lab2`	`double`: 3-element array which holds the second LAB color
`ratio`	`double`: the blend ratio of `lab1` to `lab2` Value is between 0.0 and 1.0 inclusive.
`outResult`	`double`: 3-element array which holds the resulting LAB components

calculateContrast

public static double calculateContrast (int foreground, 
                int background)

Returns the contrast ratio between foreground and background. background must be opaque.

Formula defined here.

Parameters
`foreground`	`int`
`background`	`int`

Returns
`double`

calculateLuminance

public static double calculateLuminance (int color)

Returns the luminance of a color as a float between 0.0 and 1.0.

Defined as the Y component in the XYZ representation of color.

Parameters
`color`	`int`

Returns
`double`	Value is between 0.0 and 1.0 inclusive.

calculateMinimumAlpha

public static int calculateMinimumAlpha (int foreground, 
                int background, 
                float minContrastRatio)

Calculates the minimum alpha value which can be applied to foreground so that would have a contrast value of at least minContrastRatio when compared to background.

Parameters
`foreground`	`int`: the foreground color
`background`	`int`: the opaque background color
`minContrastRatio`	`float`: the minimum contrast ratio

Returns
`int`	the alpha value in the range 0-255, or -1 if no value could be calculated

colorToHSL

public static void colorToHSL (int color, 
                float[] outHsl)

Convert the ARGB color to its HSL (hue-saturation-lightness) components.

outHsl[0] is Hue [0 .. 360)
outHsl[1] is Saturation [0...1]
outHsl[2] is Lightness [0...1]

Parameters
`color`	`int`: the ARGB color to convert. The alpha component is ignored
`outHsl`	`float`: 3-element array which holds the resulting HSL components

colorToLAB

public static void colorToLAB (int color, 
                double[] outLab)

Convert the ARGB color to its CIE Lab representative components.

Parameters
`color`	`int`: the ARGB color to convert. The alpha component is ignored
`outLab`	`double`: 3-element array which holds the resulting LAB components

colorToXYZ

public static void colorToXYZ (int color, 
                double[] outXyz)

Convert the ARGB color to its CIE XYZ representative components.

The resulting XYZ representation will use the D65 illuminant and the CIE 2° Standard Observer (1931).

outXyz[0] is X [0 ...95.047)
outXyz[1] is Y [0...100)
outXyz[2] is Z [0...108.883)

Parameters
`color`	`int`: the ARGB color to convert. The alpha component is ignored
`outXyz`	`double`: 3-element array which holds the resulting LAB components

compositeColors

public static Color compositeColors (Color foreground, 
                Color background)

Composites two translucent colors together. More specifically, adds two colors using the source over blending mode. The colors must not be pre-multiplied and the result is a non pre-multiplied color.

If the two colors have different color spaces, the foreground color is converted to the color space of the background color.

The following example creates a purple color by blending opaque blue with semi-translucent red:

Color purple = ColorUtils.compositeColors(
         Color.valueOf(1f, 0f, 0f, 0.5f),
         Color.valueOf(0f, 0f, 1f));

Note: This method requires API 26 or newer.

Parameters
`foreground`	`Color`
`background`	`Color`

Returns
`Color`

Throws
`IllegalArgumentException`	if the models of the colors do not match

compositeColors

public static int compositeColors (int foreground, 
                int background)

Composite two potentially translucent colors over each other and returns the result.

Parameters
`foreground`	`int`
`background`	`int`

Returns
`int`

distanceEuclidean

public static double distanceEuclidean (double[] labX, 
                double[] labY)

Returns the euclidean distance between two LAB colors.

Parameters
`labX`	`double`
`labY`	`double`

Returns
`double`

setAlphaComponent

public static int setAlphaComponent (int color, 
                int alpha)

Set the alpha component of color to be alpha.

Parameters
`color`	`int`
`alpha`	`int` Value is 255 or less.

Returns
`int`