Added in API level 26

ColorSpace


abstract class ColorSpace
kotlin.Any
   ↳ android.graphics.ColorSpace

A ColorSpace is used to identify a specific organization of colors. Each color space is characterized by a color model that defines how a color value is represented (for instance the RGB color model defines a color value as a triplet of numbers).

Each component of a color must fall within a valid range, specific to each color space, defined by getMinValue(int) and getMaxValue(int) This range is commonly \([0..1]\). While it is recommended to use values in the valid range, a color space always clamps input and output values when performing operations such as converting to a different color space.

Using color spaces

This implementation provides a pre-defined set of common color spaces described in the Named enum. To obtain an instance of one of the pre-defined color spaces, simply invoke get(android.graphics.ColorSpace.Named):

ColorSpace sRgb = ColorSpace.get(ColorSpace.Named.SRGB);
  

The get(android.graphics.ColorSpace.Named) method always returns the same instance for a given name. Color spaces with an RGB color model can be safely cast to Rgb. Doing so gives you access to more APIs to query various properties of RGB color models: color gamut primaries, transfer functions, conversions to and from linear space, etc. Please refer to Rgb for more information.

The documentation of Named provides a detailed description of the various characteristics of each available color space.

Color space conversions

To allow conversion between color spaces, this implementation uses the CIE XYZ profile connection space (PCS). Color values can be converted to and from this PCS using toXyz(float[]) and fromXyz(float[]).

For color space with a non-RGB color model, the white point of the PCS must be the CIE standard illuminant D50. RGB color spaces use their native white point (D65 for sRGB for instance and must undergo chromatic adaptation as necessary.

Since the white point of the PCS is not defined for RGB color space, it is highly recommended to use the variants of the connect(android.graphics.ColorSpace,android.graphics.ColorSpace) method to perform conversions between color spaces. A color space can be manually adapted to a specific white point using adapt(android.graphics.ColorSpace,float[]). Please refer to the documentation of RGB color spaces for more information. Several common CIE standard illuminants are provided in this class as reference (see ILLUMINANT_D65 or ILLUMINANT_D50 for instance).

Here is an example of how to convert from a color space to another:

// Convert from DCI-P3 to Rec.2020
  ColorSpace.Connector connector = ColorSpace.connect(
          ColorSpace.get(ColorSpace.Named.DCI_P3),
          ColorSpace.get(ColorSpace.Named.BT2020));
 
  float[] bt2020 = connector.transform(p3r, p3g, p3b);
  

You can easily convert to sRGB by omitting the second parameter:

// Convert from DCI-P3 to sRGB
  ColorSpace.Connector connector = ColorSpace.connect(ColorSpace.get(ColorSpace.Named.DCI_P3));
 
  float[] sRGB = connector.transform(p3r, p3g, p3b);
  

Conversions also work between color spaces with different color models:

// Convert from CIE L*a*b* (color model Lab) to Rec.709 (color model RGB)
  ColorSpace.Connector connector = ColorSpace.connect(
          ColorSpace.get(ColorSpace.Named.CIE_LAB),
          ColorSpace.get(ColorSpace.Named.BT709));
  

Color spaces and multi-threading

Color spaces and other related classes (Connector for instance) are immutable and stateless. They can be safely used from multiple concurrent threads.

Public static methods provided by this class, such as get(android.graphics.ColorSpace.Named) and connect(android.graphics.ColorSpace,android.graphics.ColorSpace), are also guaranteed to be thread-safe.

Summary

Nested classes

List of adaptation matrices that can be used for chromatic adaptation using the von Kries transform.

open

A connector transforms colors from a source color space to a destination color space.

A color model is required by a ColorSpace to describe the way colors can be represented as tuples of numbers.

List of common, named color spaces.

A render intent determines how a connector maps colors from one color space to another.

open

An RGB color space is an additive color space using the RGB color model (a color is therefore represented by a tuple of 3 numbers).

Constants
static Int

The maximum ID value a color space can have.

static Int

The minimum ID value a color space can have.

Public methods
open static ColorSpace
adapt(colorSpace: ColorSpace, whitePoint: FloatArray)

Performs the chromatic adaptation of a color space from its native white point to the specified white point.

open static ColorSpace
adapt(colorSpace: ColorSpace, whitePoint: FloatArray, adaptation: ColorSpace.Adaptation)

Performs the chromatic adaptation of a color space from its native white point to the specified white point.

open static FloatArray
cctToXyz(cct: Int)

Computes the chromaticity coordinates of a specified correlated color temperature (CCT) on the Planckian locus.

open static FloatArray
chromaticAdaptation(adaptation: ColorSpace.Adaptation, srcWhitePoint: FloatArray, dstWhitePoint: FloatArray)

Computes the chromatic adaptation transform from the specified source white point to the specified destination white point.

open static ColorSpace.Connector
connect(source: ColorSpace, destination: ColorSpace)

Connects two color spaces to allow conversion from the source color space to the destination color space.

open static ColorSpace.Connector
connect(source: ColorSpace, destination: ColorSpace, intent: ColorSpace.RenderIntent)

Connects two color spaces to allow conversion from the source color space to the destination color space.

open static ColorSpace.Connector

Connects the specified color spaces to sRGB.

open static ColorSpace.Connector

Connects the specified color spaces to sRGB.

open Boolean
equals(other: Any?)

open FloatArray
fromXyz(x: Float, y: Float, z: Float)

Converts tristimulus values from the CIE XYZ space to this color space's color model.

abstract FloatArray

Converts tristimulus values from the CIE XYZ space to this color space's color model.

open static ColorSpace

Returns an instance of ColorSpace identified by the specified name.

open Int

Returns the number of components that form a color value according to this color space's color model.

open Int

Retrieve the DataSpace value from a ColorSpace object.

open static ColorSpace?
getFromDataSpace(dataSpace: Int)

Create a ColorSpace object using a DataSpace value.

open Int

Returns the ID of this color space.

abstract Float
getMaxValue(component: Int)

Returns the maximum valid value for the specified component of this color space's color model.

abstract Float
getMinValue(component: Int)

Returns the minimum valid value for the specified component of this color space's color model.

open ColorSpace.Model

Return the color model of this color space.

open String

Returns the name of this color space.

open Int

open Boolean

Indicates whether this color space is the sRGB color space or equivalent to the sRGB color space.

abstract Boolean

Returns whether this color space is a wide-gamut color space.

open static ColorSpace?

Returns a Named instance of ColorSpace that matches the specified RGB to CIE XYZ transform and transfer functions.

open String

Returns a string representation of the object.

open FloatArray
toXyz(r: Float, g: Float, b: Float)

Converts a color value from this color space's model to tristimulus CIE XYZ values.

abstract FloatArray

Converts a color value from this color space's model to tristimulus CIE XYZ values.

Properties
static FloatArray!

Standard CIE 1931 2° illuminant A, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant B, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant C, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant D50, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant D55, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant D60, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant D65, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant D75, encoded in xyY.

static FloatArray!

Standard CIE 1931 2° illuminant E, encoded in xyY.

Constants

MAX_ID

Added in API level 26
static val MAX_ID: Int

The maximum ID value a color space can have.

Value: 63

See Also

MIN_ID

Added in API level 26
static val MIN_ID: Int

The minimum ID value a color space can have.

Value: -1

See Also

Public methods

adapt

Added in API level 26
open static fun adapt(
    colorSpace: ColorSpace,
    whitePoint: FloatArray
): ColorSpace

Performs the chromatic adaptation of a color space from its native white point to the specified white point.

The chromatic adaptation is performed using the Adaptation#BRADFORD matrix.

The color space returned by this method always has an ID of MIN_ID.

Parameters
colorSpace ColorSpace: The color space to chromatically adapt This value cannot be null.
whitePoint FloatArray: The new white point This value cannot be null.
Return
ColorSpace A ColorSpace instance with the same name, primaries, transfer functions and range as the specified color space This value cannot be null.

adapt

Added in API level 26
open static fun adapt(
    colorSpace: ColorSpace,
    whitePoint: FloatArray,
    adaptation: ColorSpace.Adaptation
): ColorSpace

Performs the chromatic adaptation of a color space from its native white point to the specified white point. If the specified color space does not have an RGB color model, or if the color space already has the target white point, the color space is returned unmodified.

The chromatic adaptation is performed using the von Kries method described in the documentation of Adaptation.

The color space returned by this method always has an ID of MIN_ID.

Parameters
colorSpace ColorSpace: The color space to chromatically adapt This value cannot be null.
whitePoint FloatArray: The new white point This value cannot be null.
adaptation ColorSpace.Adaptation: The adaptation matrix This value cannot be null.
Return
ColorSpace A new color space if the specified color space has an RGB model and a white point different from the specified white point; the specified color space otherwise This value cannot be null.

cctToXyz

Added in API level 31
open static fun cctToXyz(cct: Int): FloatArray

Computes the chromaticity coordinates of a specified correlated color temperature (CCT) on the Planckian locus. The specified CCT must be greater than 0. A meaningful CCT range is [1667, 25000].

The transform is computed using the methods in Kang et al., Design of Advanced Color - Temperature Control System for HDTV Applications, Journal of Korean Physical Society 41, 865-871 (2002).

Parameters
cct Int: The correlated color temperature, in Kelvin Value is 1 or greater
Return
FloatArray Corresponding XYZ values This value cannot be null.
Exceptions
java.lang.IllegalArgumentException If cct is invalid

chromaticAdaptation

Added in API level 31
open static fun chromaticAdaptation(
    adaptation: ColorSpace.Adaptation,
    srcWhitePoint: FloatArray,
    dstWhitePoint: FloatArray
): FloatArray

Computes the chromatic adaptation transform from the specified source white point to the specified destination white point.

The transform is computed using the von Kries method, described in more details in the documentation of Adaptation. The Adaptation enum provides different matrices that can be used to perform the adaptation.

Parameters
adaptation ColorSpace.Adaptation: The adaptation method This value cannot be null.
srcWhitePoint FloatArray: The white point to adapt from This value cannot be null.
dstWhitePoint FloatArray: The white point to adapt to This value cannot be null.
Return
FloatArray A 3x3 matrix as a non-null array of 9 floats

connect

Added in API level 26
open static fun connect(
    source: ColorSpace,
    destination: ColorSpace
): ColorSpace.Connector

Connects two color spaces to allow conversion from the source color space to the destination color space. If the source and destination color spaces do not have the same profile connection space (CIE XYZ with the same white point), they are chromatically adapted to use the CIE standard illuminant D50 as needed.

If the source and destination are the same, an optimized connector is returned to avoid unnecessary computations and loss of precision.

Colors are mapped from the source color space to the destination color space using the perceptual render intent.

Parameters
source ColorSpace: The color space to convert colors from This value cannot be null.
destination ColorSpace: The color space to convert colors to This value cannot be null.
Return
ColorSpace.Connector A non-null connector between the two specified color spaces

connect

Added in API level 26
open static fun connect(
    source: ColorSpace,
    destination: ColorSpace,
    intent: ColorSpace.RenderIntent
): ColorSpace.Connector

Connects two color spaces to allow conversion from the source color space to the destination color space. If the source and destination color spaces do not have the same profile connection space (CIE XYZ with the same white point), they are chromatically adapted to use the CIE standard illuminant D50 as needed.

If the source and destination are the same, an optimized connector is returned to avoid unnecessary computations and loss of precision.

Parameters
source ColorSpace: The color space to convert colors from This value cannot be null.
destination ColorSpace: The color space to convert colors to This value cannot be null.
intent ColorSpace.RenderIntent: The render intent to map colors from the source to the destination This value cannot be null.
Return
ColorSpace.Connector A non-null connector between the two specified color spaces

connect

Added in API level 26
open static fun connect(source: ColorSpace): ColorSpace.Connector

Connects the specified color spaces to sRGB. If the source color space does not use CIE XYZ D65 as its profile connection space, the two spaces are chromatically adapted to use the CIE standard illuminant D50 as needed.

If the source is the sRGB color space, an optimized connector is returned to avoid unnecessary computations and loss of precision.

Colors are mapped from the source color space to the destination color space using the perceptual render intent.

Parameters
source ColorSpace: The color space to convert colors from This value cannot be null.
Return
ColorSpace.Connector A non-null connector between the specified color space and sRGB

connect

Added in API level 26
open static fun connect(
    source: ColorSpace,
    intent: ColorSpace.RenderIntent
): ColorSpace.Connector

Connects the specified color spaces to sRGB. If the source color space does not use CIE XYZ D65 as its profile connection space, the two spaces are chromatically adapted to use the CIE standard illuminant D50 as needed.

If the source is the sRGB color space, an optimized connector is returned to avoid unnecessary computations and loss of precision.

Parameters
source ColorSpace: The color space to convert colors from This value cannot be null.
intent ColorSpace.RenderIntent: The render intent to map colors from the source to the destination This value cannot be null.
Return
ColorSpace.Connector A non-null connector between the specified color space and sRGB

equals

Added in API level 26
open fun equals(other: Any?): Boolean
Parameters
obj the reference object with which to compare.
Return
Boolean true if this object is the same as the obj argument; false otherwise.

fromXyz

Added in API level 26
open fun fromXyz(
    x: Float,
    y: Float,
    z: Float
): FloatArray

Converts tristimulus values from the CIE XYZ space to this color space's color model.

Parameters
x Float: The X component of the color value
y Float: The Y component of the color value
z Float: The Z component of the color value
Return
FloatArray A new array whose size is equal to the number of color components as returned by Model#getComponentCount() This value cannot be null.

fromXyz

Added in API level 26
abstract fun fromXyz(v: FloatArray): FloatArray

Converts tristimulus values from the CIE XYZ space to this color space's color model. The resulting value is passed back in the specified array.

The specified array's length must be at least equal to to the number of color components as returned by Model#getComponentCount(), and its first 3 values must be the XYZ components to convert from.

Parameters
v FloatArray: An array of color components containing the XYZ values to convert from, and large enough to hold the number of components of this color space's model This value cannot be null.
Return
FloatArray The array passed in parameter This value cannot be null.

get

Added in API level 26
open static fun get(name: ColorSpace.Named): ColorSpace

Returns an instance of ColorSpace identified by the specified name. The list of names provided in the Named enum gives access to a variety of common RGB color spaces.

This method always returns the same instance for a given name.

This method is thread-safe.

Note that in the Android W release and later, this can return the SRGB ColorSpace if the ColorSpace.Named parameter is not enabled in the corresponding release.
Parameters
name ColorSpace.Named: The name of the color space to get an instance of This value cannot be null.
Return
ColorSpace A non-null ColorSpace instance. If the ColorSpace is not supported then the SRGB ColorSpace is returned.

getComponentCount

Added in API level 26
open fun getComponentCount(): Int

Returns the number of components that form a color value according to this color space's color model.

Return
Int An integer between 1 and 4 Value is between 1 and 4 inclusive

getId

Added in API level 26
open fun getId(): Int

Returns the ID of this color space. Positive IDs match the color spaces enumerated in Named. A negative ID indicates a color space created by calling one of the public constructors.

Return
Int An integer between MIN_ID and MAX_ID Value is between MIN_ID and MAX_ID inclusive

getMaxValue

Added in API level 26
abstract fun getMaxValue(component: Int): Float

Returns the maximum valid value for the specified component of this color space's color model.

Parameters
component Int: The index of the component Value is between 0 and 3 inclusive
Return
Float A floating point value greater than getMinValue(int)

getMinValue

Added in API level 26
abstract fun getMinValue(component: Int): Float

Returns the minimum valid value for the specified component of this color space's color model.

Parameters
component Int: The index of the component Value is between 0 and 3 inclusive
Return
Float A floating point value less than getMaxValue(int)

getModel

Added in API level 26
open fun getModel(): ColorSpace.Model

Return the color model of this color space.

Return
ColorSpace.Model A non-null Model

getName

Added in API level 26
open fun getName(): String

Returns the name of this color space. The name is never null and contains always at least 1 character.

Color space names are recommended to be unique but are not guaranteed to be. There is no defined format but the name usually falls in one of the following categories:

  • Generic names used to identify color spaces in non-RGB color models. For instance: Generic L*a*b*.
  • Names tied to a particular specification. For instance: sRGB IEC61966-2.1 or SMPTE ST 2065-1:2012 ACES.
  • Ad-hoc names, often generated procedurally or by the user during a calibration workflow. These names often contain the make and model of the display.

Because the format of color space names is not defined, it is not recommended to programmatically identify a color space by its name alone. Names can be used as a first approximation.

It is however perfectly acceptable to display color space names to users in a UI, or in debuggers and logs. When displaying a color space name to the user, it is recommended to add extra information to avoid ambiguities: color model, a representation of the color space's gamut, white point, etc.

Return
String A non-null String of length >= 1

hashCode

Added in API level 26
open fun hashCode(): Int
Return
Int a hash code value for this object.

isSrgb

Added in API level 26
open fun isSrgb(): Boolean

Indicates whether this color space is the sRGB color space or equivalent to the sRGB color space.

A color space is considered sRGB if it meets all the following conditions:

  • Its color model is Model#RGB.
  • Its primaries are within 1e-3 of the true sRGB primaries.
  • Its white point is within 1e-3 of the CIE standard illuminant D65.
  • Its opto-electronic transfer function is not linear.
  • Its electro-optical transfer function is not linear.
  • Its transfer functions yield values within 1e-3 of Named#SRGB.
  • Its range is \([0..1]\).

This method always returns true for Named#SRGB.

Return
Boolean True if this color space is the sRGB color space (or a close approximation), false otherwise

isWideGamut

Added in API level 26
abstract fun isWideGamut(): Boolean

Returns whether this color space is a wide-gamut color space. An RGB color space is wide-gamut if its gamut entirely contains the sRGB gamut and if the area of its gamut is 90% of greater than the area of the NTSC gamut.

Return
Boolean True if this color space is a wide-gamut color space, false otherwise

match

Added in API level 26
open static fun match(
    toXYZD50: FloatArray,
    function: ColorSpace.Rgb.TransferParameters
): ColorSpace?

Returns a Named instance of ColorSpace that matches the specified RGB to CIE XYZ transform and transfer functions. If no instance can be found, this method returns null.

The color transform matrix is assumed to target the CIE XYZ space a D50 standard illuminant.

Parameters
toXYZD50 FloatArray: 3x3 column-major transform matrix from RGB to the profile connection space CIE XYZ as an array of 9 floats, cannot be null
function ColorSpace.Rgb.TransferParameters: Parameters for the transfer functions This value cannot be null.
Return
ColorSpace? A non-null ColorSpace if a match is found, null otherwise

toString

Added in API level 26
open fun toString(): String

Returns a string representation of the object. This method returns a string equal to the value of:

getName() + "(id=" + getId() + ", model=" + getModel() + ")"
  

For instance, the string representation of the sRGB color space is equal to the following value:

sRGB IEC61966-2.1 (id=0, model=RGB)
  
Return
String A string representation of the object This value cannot be null.

toXyz

Added in API level 26
open fun toXyz(
    r: Float,
    g: Float,
    b: Float
): FloatArray

Converts a color value from this color space's model to tristimulus CIE XYZ values. If the color model of this color space is not RGB, it is assumed that the target CIE XYZ space uses a D50 standard illuminant.

This method is a convenience for color spaces with a model of 3 components (RGB or Model#LAB for instance). With color spaces using fewer or more components, use toXyz(float[]) instead

.
Parameters
r Float: The first component of the value to convert from (typically R in RGB)
g Float: The second component of the value to convert from (typically G in RGB)
b Float: The third component of the value to convert from (typically B in RGB)
Return
FloatArray A new array of 3 floats, containing tristimulus XYZ values This value cannot be null.

toXyz

Added in API level 26
abstract fun toXyz(v: FloatArray): FloatArray

Converts a color value from this color space's model to tristimulus CIE XYZ values. If the color model of this color space is not RGB, it is assumed that the target CIE XYZ space uses a D50 standard illuminant.

The specified array's length must be at least equal to to the number of color components as returned by Model#getComponentCount().

Parameters
v FloatArray: An array of color components containing the color space's color value to convert to XYZ, and large enough to hold the resulting tristimulus XYZ values This value cannot be null.
Return
FloatArray The array passed in parameter This value cannot be null.

Properties

ILLUMINANT_A

Added in API level 26
static val ILLUMINANT_A: FloatArray!

Standard CIE 1931 2° illuminant A, encoded in xyY. This illuminant has a color temperature of 2856K.

ILLUMINANT_B

Added in API level 26
static val ILLUMINANT_B: FloatArray!

Standard CIE 1931 2° illuminant B, encoded in xyY. This illuminant has a color temperature of 4874K.

ILLUMINANT_C

Added in API level 26
static val ILLUMINANT_C: FloatArray!

Standard CIE 1931 2° illuminant C, encoded in xyY. This illuminant has a color temperature of 6774K.

ILLUMINANT_D50

Added in API level 26
static val ILLUMINANT_D50: FloatArray!

Standard CIE 1931 2° illuminant D50, encoded in xyY. This illuminant has a color temperature of 5003K. This illuminant is used by the profile connection space in ICC profiles.

ILLUMINANT_D55

Added in API level 26
static val ILLUMINANT_D55: FloatArray!

Standard CIE 1931 2° illuminant D55, encoded in xyY. This illuminant has a color temperature of 5503K.

ILLUMINANT_D60

Added in API level 26
static val ILLUMINANT_D60: FloatArray!

Standard CIE 1931 2° illuminant D60, encoded in xyY. This illuminant has a color temperature of 6004K.

ILLUMINANT_D65

Added in API level 26
static val ILLUMINANT_D65: FloatArray!

Standard CIE 1931 2° illuminant D65, encoded in xyY. This illuminant has a color temperature of 6504K. This illuminant is commonly used in RGB color spaces such as sRGB, BT.709, etc.

ILLUMINANT_D75

Added in API level 26
static val ILLUMINANT_D75: FloatArray!

Standard CIE 1931 2° illuminant D75, encoded in xyY. This illuminant has a color temperature of 7504K.

ILLUMINANT_E

Added in API level 26
static val ILLUMINANT_E: FloatArray!

Standard CIE 1931 2° illuminant E, encoded in xyY. This illuminant has a color temperature of 5454K.