Class Cam16

java.lang.Object
org.pushingpixels.ephemeral.chroma.hct.Cam16
public final class Cam16 extends Object
CAM16, a color appearance model. Colors are not just defined by their hex code, but rather, a hex code and viewing conditions.

CAM16 instances also have coordinates in the CAM16-UCS space, called J*, a*, b*, or jstar, astar, bstar in code. CAM16-UCS is included in the CAM16 specification, and should be used when measuring distances between colors.

In traditional color spaces, a color can be identified solely by the observer's measurement of the color. Color appearance models such as CAM16 also use information about the environment where the color was observed, known as the viewing conditions.

For example, white under the traditional assumption of a midday sun white point is accurately measured as a slightly chromatic blue by CAM16. (roughly, hue 203, chroma 3, lightness 100)

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private final double
    astar
     
    private final double
    bstar
     
    (package private) static final double[][]
    CAM16RGB_TO_XYZ
     
    private final double
    chroma
     
    private final double
    hue
     
    private final double
    j
     
    private final double
    jstar
     
    private final double
    m
     
    private final double
    q
     
    private final double
    s
     
    private final double[]
    tempArray
     
    (package private) static final double[][]
    XYZ_TO_CAM16RGB
     

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    private
    Cam16(double hue, double chroma, double j, double q, double m, double s, double jstar, double astar, double bstar)
    All of the CAM16 dimensions can be calculated from 3 of the dimensions, in the following combinations: - {j or q} and {c, m, or s} and hue - jstar, astar, bstar Prefer using a static method that constructs from 3 of those dimensions.

  • Method Summary

    Modifier and Type
    Method
    Description
    double
    distance(Cam16 other)
    CAM16 instances also have coordinates in the CAM16-UCS space, called J*, a*, b*, or jstar, astar, bstar in code.
    static Cam16
    fromInt(int argb)
    Create a CAM16 color from a color, assuming the color was viewed in default viewing conditions.
    (package private) static Cam16
    fromIntInViewingConditions(int argb, ViewingConditions viewingConditions)
    Create a CAM16 color from a color in defined viewing conditions.
    (package private) static Cam16
    fromJch(double j, double c, double h)
     
    private static Cam16
    fromJchInViewingConditions(double j, double c, double h, ViewingConditions viewingConditions)
     
    static Cam16
    fromUcs(double jstar, double astar, double bstar)
    Create a CAM16 color from CAM16-UCS coordinates.
    static Cam16
    fromUcsInViewingConditions(double jstar, double astar, double bstar, ViewingConditions viewingConditions)
    Create a CAM16 color from CAM16-UCS coordinates in defined viewing conditions.
    (package private) static Cam16
    fromXyzInViewingConditions(double x, double y, double z, ViewingConditions viewingConditions)
     
    double
    getAstar()
    a* coordinate in CAM16-UCS
    double
    getBstar()
    b* coordinate in CAM16-UCS
    double
    getChroma()
    Chroma in CAM16
    double
    getHue()
    Hue in CAM16
    double
    getJ()
    Lightness in CAM16
    double
    getJstar()
    Lightness coordinate in CAM16-UCS
    double
    getM()
    Colorfulness in CAM16.
    double
    getQ()
    Brightness in CAM16.
    double
    getS()
    Saturation in CAM16.
    int
    toInt()
    ARGB representation of the color.
    (package private) int
    viewed(ViewingConditions viewingConditions)
    ARGB representation of the color, in defined viewing conditions.
    (package private) double[]
    xyzInViewingConditions(ViewingConditions viewingConditions, double[] returnArray)
     

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • XYZ_TO_CAM16RGB

      static final double[][] XYZ_TO_CAM16RGB

    • CAM16RGB_TO_XYZ

      static final double[][] CAM16RGB_TO_XYZ

    • hue

      private final double hue

    • chroma

      private final double chroma

    • j

      private final double j

    • q

      private final double q

    • m

      private final double m

    • s

      private final double s

    • jstar

      private final double jstar

    • astar

      private final double astar

    • bstar

      private final double bstar

    • tempArray

      private final double[] tempArray

  • Constructor Details

    • Cam16

      private Cam16(double hue, double chroma, double j, double q, double m, double s, double jstar, double astar, double bstar)
      All of the CAM16 dimensions can be calculated from 3 of the dimensions, in the following combinations: - {j or q} and {c, m, or s} and hue - jstar, astar, bstar Prefer using a static method that constructs from 3 of those dimensions. This constructor is intended for those methods to use to return all possible dimensions.
      Parameters:
      hue - for example, red, orange, yellow, green, etc.
      chroma - informally, colorfulness / color intensity. like saturation in HSL, except perceptually accurate.
      j - lightness
      q - brightness; ratio of lightness to white point's lightness
      m - colorfulness
      s - saturation; ratio of chroma to white point's chroma
      jstar - CAM16-UCS J coordinate
      astar - CAM16-UCS a coordinate
      bstar - CAM16-UCS b coordinate

  • Method Details

    • distance

      public double distance(Cam16 other)
      CAM16 instances also have coordinates in the CAM16-UCS space, called J*, a*, b*, or jstar, astar, bstar in code. CAM16-UCS is included in the CAM16 specification, and is used to measure distances between colors.

    • getHue

      public double getHue()
      Hue in CAM16

    • getChroma

      public double getChroma()
      Chroma in CAM16

    • getJ

      public double getJ()
      Lightness in CAM16

    • getQ

      public double getQ()
      Brightness in CAM16.

      Prefer lightness, brightness is an absolute quantity. For example, a sheet of white paper is much brighter viewed in sunlight than in indoor light, but it is the lightest object under any lighting.

    • getM

      public double getM()
      Colorfulness in CAM16.

      Prefer chroma, colorfulness is an absolute quantity. For example, a yellow toy car is much more colorful outside than inside, but it has the same chroma in both environments.

    • getS

      public double getS()
      Saturation in CAM16.

      Colorfulness in proportion to brightness. Prefer chroma, saturation measures colorfulness relative to the color's own brightness, where chroma is colorfulness relative to white.

    • getJstar

      public double getJstar()
      Lightness coordinate in CAM16-UCS

    • getAstar

      public double getAstar()
      a* coordinate in CAM16-UCS

    • getBstar

      public double getBstar()
      b* coordinate in CAM16-UCS

    • fromInt

      public static Cam16 fromInt(int argb)
      Create a CAM16 color from a color, assuming the color was viewed in default viewing conditions.
      Parameters:
      argb - ARGB representation of a color.

    • fromIntInViewingConditions

      static Cam16 fromIntInViewingConditions(int argb, ViewingConditions viewingConditions)
      Create a CAM16 color from a color in defined viewing conditions.
      Parameters:
      argb - ARGB representation of a color.
      viewingConditions - Information about the environment where the color was observed.

    • fromXyzInViewingConditions

      static Cam16 fromXyzInViewingConditions(double x, double y, double z, ViewingConditions viewingConditions)

    • fromJch

      static Cam16 fromJch(double j, double c, double h)
      Parameters:
      j - CAM16 lightness
      c - CAM16 chroma
      h - CAM16 hue

    • fromJchInViewingConditions

      private static Cam16 fromJchInViewingConditions(double j, double c, double h, ViewingConditions viewingConditions)
      Parameters:
      j - CAM16 lightness
      c - CAM16 chroma
      h - CAM16 hue
      viewingConditions - Information about the environment where the color was observed.

    • fromUcs

      public static Cam16 fromUcs(double jstar, double astar, double bstar)
      Create a CAM16 color from CAM16-UCS coordinates.
      Parameters:
      jstar - CAM16-UCS lightness.
      astar - CAM16-UCS a dimension. Like a* in L*a*b*, it is a Cartesian coordinate on the Y axis.
      bstar - CAM16-UCS b dimension. Like a* in L*a*b*, it is a Cartesian coordinate on the X axis.

    • fromUcsInViewingConditions

      public static Cam16 fromUcsInViewingConditions(double jstar, double astar, double bstar, ViewingConditions viewingConditions)
      Create a CAM16 color from CAM16-UCS coordinates in defined viewing conditions.
      Parameters:
      jstar - CAM16-UCS lightness.
      astar - CAM16-UCS a dimension. Like a* in L*a*b*, it is a Cartesian coordinate on the Y axis.
      bstar - CAM16-UCS b dimension. Like a* in L*a*b*, it is a Cartesian coordinate on the X axis.
      viewingConditions - Information about the environment where the color was observed.

    • toInt

      public int toInt()
      ARGB representation of the color. Assumes the color was viewed in default viewing conditions, which are near-identical to the default viewing conditions for sRGB.

    • viewed

      int viewed(ViewingConditions viewingConditions)
      ARGB representation of the color, in defined viewing conditions.
      Parameters:
      viewingConditions - Information about the environment where the color will be viewed.
      Returns:
      ARGB representation of color

    • xyzInViewingConditions

      double[] xyzInViewingConditions(ViewingConditions viewingConditions, double[] returnArray)