color

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 Go to latest Published: Dec 5, 2025 License: Apache-2.0 Imports: 9 Imported by: 0

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Index

Constants

View Source 
const CieE float64 = 216.0 / 24389.0

CieE is the threshold for linear vs. nonlinear transition. Reference

View Source 
const CieK float64 = 24389.0 / 27.0

CieK s the constant used for linear approximation. Reference

Variables

View Source 
var CatInvMatrix = num.NewMatrix3(
	1.86206786, -1.01125463, 0.14918678,
	0.38752654, 0.62144744, -0.00897399,
	-0.0158415, -0.03412294, 1.04996444,
)

CatInvMatrix is the inverse of CatMatrix.

It converts CAM16 LMS cone responses back into linear RGB values, reversing the chromatic adaptation process. This matrix is used when converting from the CAM16/HCT perceptual space back to RGB.

View Source 
var CatMatrix = num.NewMatrix3(
	0.401288, 0.650173, -0.051461,
	-0.250268, 1.204414, 0.045854,
	-0.002079, 0.048952, 0.953127,
)

CatMatrix is the forward CAT (Chromatic Adaptation Transform) matrix.

It converts linear RGB values into the CAM16 LMS (Long, Medium, Short) cone response domain. This step models how the human visual system adapts to different white points and viewing conditions.

The CAT16 matrix is part of the CAM16 color appearance model used by the HCT color system.

View Source 
var CriticalPlanes = []float64{}/* 255 elements not displayed */

CriticalPlanes is used for converting Hct to ARGB

View Source 
var DefaultEnvironment = NewEnvironment(adaptingLuminance, 50, 2, false)

DefaultEnvironment returns the default sRGB-like viewing conditions.

View Source 
var LinrgbFromScaledDiscount = num.NewMatrix3(
	1373.2198709594231, -1100.4251190754821, -7.278681089101213,
	-271.815969077903, 559.6580465940733, -32.46047482791194,
	1.9622899599665666, -57.173814538844006, 308.7233197812385,
)

LinrgbFromScaledDiscount is the inverse of ScaledDiscountFromLinRGB.

It converts values from the scaled discount space back into linear RGB, reconstructing displayable color values from the perceptual model (used when converting HCT → RGB).

View Source 
var OkLabMatrix1 = num.NewMatrix3(
	0.8189330101, 0.3618667424, -0.1288597137,
	0.0329845436, 0.9293118715, 0.0361456387,
	0.0482003018, 0.2643662691, 0.6338517070,
)

OkLabMatrix1 defines the linear transformation from CIE XYZ to LMS cone responses used in the OkLab color model.

This corresponds to the matrix M1 in Ottosson’s paper: 

[L, M, S]^T = M1 * [X, Y, Z]^T
View Source 
var OkLabMatrix1Inv = num.NewMatrix3(
	1.2270138511, -0.5577999807, 0.2812561490,
	-0.0405801784, 1.1122568696, -0.0716766787,
	-0.0763812845, -0.4214819784, 1.5861632204,
)

OkLabMatrix1Inv is the inverse of M1, used to convert from LMS back to XYZ.

View Source 
var OkLabMatrix2 = num.NewMatrix3(
	0.2104542553, 0.7936177850, -0.0040720468,
	1.9779984951, -2.4285922050, 0.4505937099,
	0.0259040371, 0.7827717662, -0.8086757660,
)

OkLabMatrix2 defines the transformation from nonlinearly transformed LMS (after cube-root compression) to OkLab coordinates (L, a, b).

This corresponds to matrix M2 in Ottosson’s formulation: 

[L, a, b]^T = M2 * [L', M', S']^T
View Source 
var OkLabMatrix2Inv = num.NewMatrix3(
	0.9999999985, 0.3963377922, 0.2158037581,
	1.0000000089, -0.1055613423, -0.0638541748,
	1.0000000547, -0.0894841821, -1.2914855379,
)

OkLabMatrix2Inv is the inverse of M2, used to convert from OkLab (L,a,b) back to cube-rooted LMS values.

View Source 
var RGB_TO_XYZ = num.NewMatrix3(
	0.41233895, 0.35762064, 0.18051042,
	0.2126, 0.7152, 0.0722,
	0.01932141, 0.11916382, 0.95034478,
)

RGB_TO_XYZ is the Matrix3 that is used for converting sRGB colors to XYZ

View Source 
var ScaledDiscountFromLinRGB = num.NewMatrix3(
	0.001200833568784504, 0.002389694492170889, 0.0002795742885861124,
	0.0005891086651375999, 0.0029785502573438758, 0.0003270666104008398,
	0.00010146692491640572, 0.0005364214359186694, 0.0032979401770712076,
)

ScaledDiscountFromLinRGB is a 3×3 transform matrix that converts from linear RGB to the "scaled discount" space used internally by the CAM16/HCT color appearance model.

This transformation accounts for human visual response under standard viewing conditions, mapping linear RGB signals into a perceptual domain where hue, chroma, and tone can be computed.

View Source 
var WhitePointD65 = num.NewVector3(95.047, 100.0, 108.883)

WhitePointD65 is the white most point of XYZ to sRGB color space

View Source 
var XYZ_TO_RGB = num.NewMatrix3(
	3.2413774792388685, -1.5376652402851851, -0.49885366846268053,
	-0.9691452513005321, 1.8758853451067872, 0.04156585616912061,
	0.05562093689691305, -0.20395524564742123, 1.0571799111220335,
)

XYZ_TO_RGB is the Matrix3 that is used for converting XYZ colors to sRGB

View Source 
var YFromLinRGB = num.NewVector3(0.2126, 0.7152, 0.0722)

YFromLinRGB vector is used to get Y star of CieLab from linear RGB

Functions

func Delinearized 

func Delinearized(component float64) uint8

Delinearized takes component (float64) that represents linear R/G/B channel. Component should be 0.0 < component < 1.0. Returns uint8 (0 <= n <= 255) representation of color component.

func IsBlue 

func IsBlue(hue float64) bool

IsBlue reports whether hue falls in the blue range [250, 270].

func IsCyan 

func IsCyan(hue float64) bool

IsCyan reports whether hue falls in the cyan range [170, 207].

func IsYellow 

func IsYellow(hue float64) bool

IsYellow reports whether hue falls in the yellow range [105, 125].

func Linearized 

func Linearized(component uint8) float64

Linearized takes component (uint8) that represents R/G/B channel. Returns 0.0 <= output <= 1.0, color channel converted to linear RGB space

func LstarFromY 

func LstarFromY(y float64) float64

LstarFromY converts Y (relative luminance) in the XYZ color space to L* (perceptual luminance) in the CIELAB color space.

Both Y and L* represent luminance, but Y is linear and L* is perceptually uniform.

y is the Y value in the XYZ color space. It returns the corresponding L* value in the CIELAB color space.

func YFromLstar 

func YFromLstar(lstar float64) float64

YFromLstar converts an L* (perceptual luminance) value from the CIELAB color space to Y (relative luminance) in the XYZ color space.

Both L* and Y represent luminance, but L* is perceptually uniform and Y is linear.

lstar is the L* value in the CIELAB color space. It returns the corresponding Y value in the XYZ color space.

Types

type ARGB 

type ARGB uint32

ARGB represents a 32-bit color in ARGB format (Alpha, Red, Green, Blue) packed into a uint32. It implements the color.Color interface.

func ARGBFromHex 

func ARGBFromHex(hex string) (ARGB, error)

ARGBFromHex parses a hex color string and returns an ARGB color. hex is the hexadecimal color string to parse. Returns the parsed ARGB color and error if the RGB hex is invalid.

Supports formats: #RGB, #RGBA, #RRGGBB, #RRGGBBAA.

TODO: optimize me...

func ARGBFromHexMust 

func ARGBFromHexMust(hex string) ARGB

ARGBFromHexMust parses a hex color string and returns an ARGB color. Panics if the string cannot be parsed. Supports formats: #RGB, #RGBA, #RRGGBB, #RRGGBBAA. hex: The hexadecimal color string to parse Returns the parsed ARGB color.

func ARGBFromInterface 

func ARGBFromInterface(c color.Color) ARGB

ARGBFromInterface converts any color.Color implementation to ARGB. It handles the 16-bit to 8-bit conversion automatically.

func ARGBFromLinearRGB 

func ARGBFromLinearRGB(r, g, b float64) ARGB

ARGBFromLinearRGB creates an opaque ARGB color from linear RGB components. r, g, b are linear RGB components (0-100). Returns the corresponding opaque ARGB color after delinearization.

func ARGBFromLstar 

func ARGBFromLstar(lstar float64) ARGB

ARGBFromLstar converts a CIE L* (lightness) value to an ARGB grayscale color. lstar is lightness value in the L*a*b* color space (0-100) Returns an ARGB grayscale color matching the specified lightness.

func ARGBFromRGB 

func ARGBFromRGB(r, g, b uint8) ARGB

ARGBFromRGB creates an opaque ARGB color (alpha=255) from 8-bit RGB components. r, g, b are the red, green, and blue components (0-255) Returns the corresponding opaque ARGB color.

func ARGBFromXYZ 

func ARGBFromXYZ(x, y, z float64) ARGB

ARGBFromXYZ creates an ARGB color from XYZ color space coordinates. x, y, z are the coordinates in the CIE 1931 XYZ color space Returns the corresponding ARGB color.

func NewARGB 

func NewARGB(a, r, g, b uint8) ARGB

NewARGB creates an ARGB color from individual 8-bit alpha, red, green, and blue components. The components are packed into a uint32 in ARGB order.

func (ARGB) Alpha 

func (c ARGB) Alpha() uint8

Alpha returns the 8-bit alpha component of the color (0-255).

func (ARGB) AnsiBg 

func (c ARGB) AnsiBg(text string) string

AnsiBg wraps the given text with ANSI escape codes for this background color. text is the string to be colored Returns the string wrapped with ANSI background color codes.

func (ARGB) AnsiFg 

func (c ARGB) AnsiFg(text string) string

AnsiFg wraps the given text with ANSI escape codes for this foreground color. text is the string to be colored Returns the string wrapped with ANSI foreground color codes.

func (ARGB) Blue 

func (c ARGB) Blue() uint8

Blue returns the 8-bit blue component of the color (0-255).

func (ARGB) Components 

func (c ARGB) Components() (alpha uint8, red uint8, green uint8, blue uint8)

Components returns the individual 8-bit components of the ARGB color. Returns alpha, red, green, blue components in order (0-255).

func (ARGB) Green 

func (c ARGB) Green() uint8

Green returns the 8-bit green component of the color (0-255).

func (ARGB) HexARGB 

func (c ARGB) HexARGB() string

HexARGB returns the hexadecimal representation of the color in #AARRGGBB format.

func (ARGB) HexRGB 

func (c ARGB) HexRGB() string

HexRGB returns the hexadecimal representation of the color in #RRGGBB format.

func (ARGB) HexRGBA 

func (c ARGB) HexRGBA() string

HexRGBA returns the hexadecimal representation of the color in #RRGGBBAA format.

func (ARGB) LStar 

func (c ARGB) LStar() float64

LStar calculates the CIE L* (lightness) value of the color. Returns the L* value (0-100) representing the perceived lightness.

func (ARGB) MarshalText 

func (c ARGB) MarshalText() ([]byte, error)

MarshalText implements the encoding.TextMarshaler interface. Returns the hexadecimal representation of the color (#RRGGBBAA format).

func (ARGB) RGBA 

func (c ARGB) RGBA() (red uint32, green uint32, blue uint32, alpha uint32)

RGBA implements the color.Color interface. Returns the red, green, blue, and alpha values in the 0-65535 range.

func (ARGB) Red 

func (c ARGB) Red() uint8

Red returns the 8-bit red component of the color (0-255).

func (ARGB) String 

func (c ARGB) String() string

String returns a string representation of the color hex code. Eg. #FF00FF

func (ARGB) ToCam16 

func (c ARGB) ToCam16() Cam16

ToCam16 converts the ARGB color to CAM16 color appearance model. Returns a pointer to the Cam16 representation of the color.

func (ARGB) ToHct 

func (c ARGB) ToHct() Hct

ToHct converts the ARGB color to HCT (Hue-Chroma-Tone) color space. Returns the HCT representation of the color.

func (ARGB) ToLCHab 

func (c ARGB) ToLCHab() LCHab

ToLCHab convets XYZ to LCHab color model

func (ARGB) ToLCHuv 

func (c ARGB) ToLCHuv() LCHuv

ToLCHuv convets XYZ to LCHuv color model

func (ARGB) ToLab 

func (c ARGB) ToLab() Lab

ToLab converts the ARGB color to CIE L*a*b* color space. Returns the Lab representation of the color.

func (ARGB) ToLinearRGB 

func (c ARGB) ToLinearRGB() LinearRGB

ToLinearRGB converts the ARGB color to Linear RGB color space.

func (ARGB) ToLuv 

func (c ARGB) ToLuv() Luv

ToLuv convets XYZ to CIELUV color model

func (ARGB) ToOkLab 

func (c ARGB) ToOkLab() OkLab

ToOkLab converts the ARGB color to CIE L*a*b* color space. Returns the OkLab representation of the color.

func (ARGB) ToXYZ 

func (c ARGB) ToXYZ() XYZ

ToXYZ converts the ARGB color to CIE XYZ color space. Returns the XYZ representation of the color.

func (*ARGB) UnmarshalText 

func (c *ARGB) UnmarshalText(data []byte) error

UnmarshalText implements the encoding.UnmarshalText interface. Accepts #RRGGBB, #RRGGBBAA, RRGGBB, or RRGGBBAA formats for performance reasons. Returns an error if the string cannot be parsed as a valid color.

type Cam16 

type Cam16 struct {
	// Hue represents the hue of the color
	Hue float64 `json:"hue"`
	// Chroma represents the colorfulness or color intensity, similar to
	// saturation in HSL but more perceptually accurate
	Chroma float64 `json:"chroma"`
	// J represents the lightness of the color
	J float64 `json:"j"`
	// Q represents the brightness, which is the ratio of lightness to
	// the white point's lightness
	Q float64 `json:"q"`
	// M represents the colorfulness of the color
	M float64 `json:"m"`
	// S represents the saturation, which is the ratio of chroma to
	// the white point's chroma
	S float64 `json:"s"`
	// Jstar represents the CAM16-UCS J coordinate
	Jstar float64 `json:"jstar"`
	// Astar represents the CAM16-UCS a coordinate
	Astar float64 `json:"astar"`
	// Bstar represents the CAM16-UCS b coordinate
	Bstar float64 `json:"bstar"`
}

Cam16 represents the CAM16 color model, which includes various dimensions for color representation. It can be constructed using any combination of three of the following dimensions: j or q, c, m, or s, and hue. It can also be constructed using the CAM16-UCS J, a, and b coordinates.

func Cam16FromJch 

func Cam16FromJch(j, c, h float64) Cam16

Cam16FromJch constructs a Cam16 color from J (lightness), C (chroma), and H (hue angle in degrees), using DefaultViewingConditions viewing conditions.

This is used when synthesizing a CAM16 color from HCT values or performing color space conversions into perceptual models.

func Cam16FromJchInEnv 

func Cam16FromJchInEnv(j, c, h float64, env Environment) Cam16

Cam16FromJchInEnv constructs a Cam16 color from J (lightness), C (chroma), and H (hue angle in degrees), using the given viewing conditions.

This is used when synthesizing a CAM16 color from HCT values or performing color space conversions into perceptual models.

func Cam16FromUcs 

func Cam16FromUcs(jstar, astar, bstar float64) Cam16

Cam16FromUcs creates a CAM16 color from UCS coordinates (jstar, astar, bstar). Uses the default viewing environment for conversion.

func Cam16FromUcsInEnv 

func Cam16FromUcsInEnv(jstar, astar, bstar float64, env Environment) Cam16

Cam16FromUcsInEnv creates a CAM16 color from UCS coordinates (jstar, astar, bstar) using the specified viewing environment for conversion.

func Cam16FromXYZInEnv 

func Cam16FromXYZInEnv(xyz XYZ, env Environment) Cam16

Cam16FromXYZInEnv create a Cam16 color In specific ViewingConditions

func NewCam16 

func NewCam16(hue, chroma, j, q, m, s, jstar, astar, bstar float64) Cam16

NewCam16 create a CAM16 color model from given values

func (Cam16) Distance 

func (c Cam16) Distance(other Cam16) float64

Distance returns distance between to Cam16 color

func (Cam16) ToARGB 

func (c Cam16) ToARGB() ARGB

ToARGB converts the CAM16 color to ARGB format. Uses the default viewing environment for conversion.

func (Cam16) ToHct 

func (c Cam16) ToHct() Hct

ToHct converts the CAM16 color to HCT (Hue, Chroma, Tone) color space.

func (Cam16) ToLab 

func (c Cam16) ToLab() Lab

ToLab converts the CAM16 color to CIE L*a*b* color space. Uses the default viewing environment for conversion.

func (Cam16) ToXYZ 

func (c Cam16) ToXYZ() XYZ

ToXYZ converts the CAM16 color to CIE XYZ color space. Uses the default viewing environment for conversion.

func (Cam16) Viewed 

func (c Cam16) Viewed(vc Environment) XYZ

Viewed converts a CAM16 color to an ARGB integer based on the given viewing conditions.

type Environment 

type Environment struct {
	// N is the relative luminance of the background relative to the reference
	// white.
	N float64
	// Aw is the achromatic response to the white point.
	Aw float64
	// Nbb is the brightness induction factor (background).
	Nbb float64
	// Ncb is the chromatic induction factor (background).
	Ncb float64
	// C is the surround exponential non-linearity factor.
	C float64
	// Nc is the chromatic induction factor (surround).
	Nc float64
	// RgbD is the degree of adaptation for each RGB channel after discounting
	// the illuminant.
	RgbD num.Vector3
	// Fl is the luminance-level adaptation factor (nonlinear response).
	Fl float64
	// FlRoot is the fourth root of Fl, used in CAM16 computations.
	FlRoot float64
	// Z is a base exponential factor used in the CAM16 J calculation.
	Z float64
}

Environment encapsulates all constants needed for CAM16 color conversions. These are intermediate values derived from the viewing environment and are used throughout the CAM16 model to compute perceptual color attributes.

func NewEnvironment 

func NewEnvironment(
	adaptingLuminance float64,
	backgroundLstar float64,
	surround float64,
	discountingIlluminant bool,
) Environment

NewEnvironment creates a ViewingConditions instance with the specified parameters.

type Hct 

type Hct struct {
	// Hue is the color angle in degrees [0, 360], where 0° is red, 120° is
	// green, and 240° is blue. Values outside this range are normalized.
	Hue float64 `json:"hue"`
	// Chroma is the colorfulness of the color [0, ~150]. Higher values
	// represent more saturated colors. The maximum chroma varies depending on
	// hue and tone.
	Chroma float64 `json:"chroma"`
	// Tone is the lightness or luminance of the color [0, 100], where 0 is
	// black, 50 is mid-tone, and 100 is white. Invalid values are clamped to
	// this range.
	Tone float64 `json:"tone"`
}

Hct represents a color in the HCT (Hue, Chroma, Tone) color space.

HCT is a perceptually accurate color measurement system designed to render colors consistently across different lighting environments.

func NewHct 

func NewHct(hue, chroma, tone float64) Hct

NewHct creates an HCT color from hue, chroma, and tone values. Hue values outside [0, 360] are normalized. Chroma and tone values outside their valid ranges are adjusted accordingly.

func (Hct) Hash 

func (h Hct) Hash() [3]int64

Hash generates a uint64 hash value for the HCT color. Returns uint64 - Efficient hash value for color comparison.

func (Hct) InViewingConditions 

func (h Hct) InViewingConditions(env Environment) Hct

InViewingConditions adjusts color appearance for different environments. Uses CAM16 color appearance model to account for viewing conditions. env is environment containing viewing condition parameters. Returns Hct color adjusted for specified viewing conditions.

func (Hct) IsBlue 

func (h Hct) IsBlue() bool

IsBlue reports whether the color's hue falls in the blue range [250, 270].

func (Hct) IsCyan 

func (h Hct) IsCyan() bool

IsCyan reports whether the color's hue falls in the cyan range [170, 207].

func (Hct) IsYellow 

func (h Hct) IsYellow() bool

IsYellow reports whether the color's hue falls in the yellow range [105, 125].

func (Hct) String 

func (h Hct) String() string

String returns a formatted string representation of HCT color.

func (Hct) ToARGB 

func (h Hct) ToARGB() ARGB

ToARGB converts HCT color to ARGB representation. Returns ARGB - 32-bit packed color value.

func (Hct) ToCam16 

func (h Hct) ToCam16() Cam16

ToCam16 converts HCT color to CAM16 color appearance model. Returns *Cam16 - Pointer to CAM16 color representation.

func (Hct) ToHct 

func (h Hct) ToHct() Hct

ToHct returns the receiver (implements digitalColor interface). Returns Hct - The color itself.

func (Hct) ToLab 

func (h Hct) ToLab() Lab

ToLab converts HCT color to CIE L*a*b* color space. Returns Lab - CIE L*a*b* color representation.

func (Hct) ToXYZ 

func (h Hct) ToXYZ() XYZ

ToXYZ converts HCT color to CIE XYZ color space. Returns XYZ - CIE XYZ color representation.

func (Hct) Values 

func (h Hct) Values() (float64, float64, float64)

Values returns Hue, Chroma and Tone

type LCHab 

type LCHab struct {
	L float64 `json:"l"`
	C float64 `json:"c"`
	H float64 `json:"h"`
}

LCHab represents a color in the CIE LCHab color space, a cylindrical transformation of the CIE 1976 (L*, a*, b*) color space (CIELAB). It defines a color using lightness (L), chroma (C), and hue (H), providing a more perceptually uniform and intuitive model for color manipulation compared to the Cartesian Lab model.

func LchFromLab 

func LchFromLab(c Lab) LCHab

LchFromLab converts a color from the CIELAB color space to the cylindrical LCHab representation.

func NewLCHab 

func NewLCHab(l, c, h float64) LCHab

NewLCHab creates a new LCHab color from the given lightness (L), chroma (C), and hue (H) values.

func (LCHab) String 

func (c LCHab) String() string

String returns a formatted string representation of LCH(ab) color.

func (LCHab) ToARGB 

func (c LCHab) ToARGB() ARGB

ToARGB converts the LCHab color to the ARGB color model.

func (LCHab) ToLab 

func (c LCHab) ToLab() Lab

ToLab converts the LCHab color back to the CIELAB color space.

func (LCHab) ToXYZ 

func (c LCHab) ToXYZ() XYZ

ToXYZ converts the LCHab color to the CIE 1931 XYZ color space.

func (LCHab) Values 

func (c LCHab) Values() (float64, float64, float64)

Values returns the individual components (L, C, H) of the LCHab color.

type LCHuv 

type LCHuv struct {
	L float64 `json:"l"`
	C float64 `json:"c"`
	H float64 `json:"h"`
}

LCHuv represents a color in the CIE LCHuv color space, a cylindrical transformation of the CIE 1976 (L*, u*, v*) color space (CIELUV). It defines a color using lightness (L), chroma (C), and hue (H), which provides a more intuitive representation for color manipulation.

func LchFromLuv 

func LchFromLuv(c Luv) LCHuv

LchFromLuv converts a color from the CIELUV color space to the cylindrical LCHuv representation (LuvLch).

func NewLCHuv 

func NewLCHuv(l, c, h float64) LCHuv

NewLCHuv creates a new LuvLch color from the given lightness (L), chroma (C), and hue (H) values.

func (LCHuv) ToARGB 

func (c LCHuv) ToARGB() ARGB

ToARGB converts the LCHuv color to the ARGB color model.

func (LCHuv) ToLuv 

func (c LCHuv) ToLuv() Luv

ToLuv converts the LCHuv color (LuvLch) back to the CIELUV color space.

func (LCHuv) ToXYZ 

func (c LCHuv) ToXYZ() XYZ

ToXYZ converts the LCHuv color to the CIE 1931 XYZ color space.

func (LCHuv) Values 

func (c LCHuv) Values() (float64, float64, float64)

Values returns the individual components (L, C, H) of the LCHuv color.

type Lab 

type Lab struct {
	L float64 `json:"l"`
	A float64 `json:"a"`
	B float64 `json:"b"`
}

Lab is the CIELAB color space, also referred to as L*a*b*, is a color space defined by the International Commission on Illumination (abbreviated CIE) in 1976. It expresses color as three values: L* for perceptual lightness and a* and b* for the four unique colors of human vision: red, green, blue and yellow. CIELAB was intended as a perceptually uniform space, where a given numerical change corresponds to a similar perceived change in color.

func NewLab 

func NewLab(l, a, b float64) Lab

NewLab creates Lab (CIELAB) color model

func (Lab) DistanceSquared 

func (c Lab) DistanceSquared(b Lab) float64

DistanceSquared returns square of distance between two color

func (Lab) LStar 

func (c Lab) LStar() float64

LStar returns the L* value of L*a*b* (LabColor)

func (Lab) LuminanceY 

func (c Lab) LuminanceY() float64

LuminanceY returns the Y value for XYZ color model from Lab color model

func (Lab) String 

func (c Lab) String() string

String returns a formatted string representation of LAB color.

func (Lab) ToARGB 

func (c Lab) ToARGB() ARGB

ToARGB returns Color (ARGB) from LabColor

func (Lab) ToLCHab 

func (c Lab) ToLCHab() LCHab

ToLCHab returns Color ToLCHab from LabColor

func (Lab) ToXYZ 

func (c Lab) ToXYZ() XYZ

ToXYZ return XYZColor from LabColor

func (Lab) Values 

func (c Lab) Values() (float64, float64, float64)

Values returns L, a, b values of LABColor color

type LinearRGB 

type LinearRGB struct {
	R float64 `json:"r"`
	G float64 `json:"g"`
	B float64 `json:"b"`
}

LinearRGB represents a color in the linear RGB color space.

Each component (R, G, and B) is expressed as a float64 value in the range [0, 100], where 0 corresponds to no intensity and 100 corresponds to full intensity. Unlike gamma-corrected RGB, LinearRGB stores values in a linear light space, making it suitable for accurate color calculations and conversions.

func LinearRGBFromARGB 

func LinearRGBFromARGB(c ARGB) LinearRGB

LinearRGBFromARGB to converts ARGB (sRGB) to linear RGB.

func LinearRGBFromXYZ 

func LinearRGBFromXYZ(c XYZ) LinearRGB

LinearRGBFromXYZ to converts ARGB (sRGB) to linear RGB.

func NewLinearRGB 

func NewLinearRGB(r, g, b float64) LinearRGB

NewLinearRGB creates a linear RGB color model

func (LinearRGB) String 

func (c LinearRGB) String() string

String returns a formatted string representation of linear sRGB color.

func (LinearRGB) ToARGB 

func (c LinearRGB) ToARGB() ARGB

ToARGB converts LinearRGB to ARGB.

func (LinearRGB) ToXYZ 

func (c LinearRGB) ToXYZ() XYZ

ToXYZ converts LinearRGB to ARGB.

func (LinearRGB) Values 

func (c LinearRGB) Values() (float64, float64, float64)

Values returns R, G, B components of LinearRGB.

type Luv 

type Luv struct {
	L float64 `json:"l"`
	U float64 `json:"a"`
	V float64 `json:"b"`
}

Luv is a color space adopted by the International Commission on Illumination (CIE) in 1976, as a simple-to-compute transformation of the 1931 CIE XYZ color space, which attempted perceptual uniformity. It is extensively used for applications such as computer graphics which deal with colored lights. Although additive mixtures of different colored lights will fall on a line in CIELUV's uniform chromaticity diagram (called the CIE 1976 UCS), such additive mixtures will not, contrary to popular belief, fall along a line in the CIELUV color space unless the mixtures are constant in lightness.

func LuvFromXYZ 

func LuvFromXYZ(c XYZ) Luv

LuvFromXYZ converts from CIE XYZ to CIE L*u*v* color space.

func NewLuv 

func NewLuv(l, u, v float64) Luv

NewLuv creates the CIELUV color model

func (Luv) String 

func (c Luv) String() string

String returns a formatted string representation of LUV color.

func (Luv) ToARGB 

func (c Luv) ToARGB() ARGB

ToARGB converts CIELUV to ARGB

func (Luv) ToLCHuv 

func (c Luv) ToLCHuv() LCHuv

ToLCHuv converts CIELUV to LCHuv

func (Luv) ToXYZ 

func (c Luv) ToXYZ() XYZ

ToXYZ converts CIELUV to CIEXYZ

func (Luv) Values 

func (c Luv) Values() (float64, float64, float64)

Values returns L, U, C values

type Model 

type Model interface {
	ToARGB() ARGB
	ToXYZ() XYZ
	String() string
	Values() (float64, float64, float64)
}

Model implements common methods for all colors in this package.

type OkLab 

type OkLab struct {
	// L for perceptual lightness, ranging from 0 (pure black) to 100 (reference
	// white), often denoted as a percentage.
	L float64 `json:"l"`
	// A for green (negative) to red (positive) in range [-100, 100].
	A float64 `json:"a"`
	// B for blue (negative) to yellow (positive) in range [-100, 100].
	B float64 `json:"b"`
}

OkLab color space is a uniform color space for device-independent color designed to improve perceptual uniformity, hue and lightness prediction, color blending, and usability while ensuring numerical stability and ease of implementation. Introduced by Björn Ottosson in December 2020.

func NewOkLab 

func NewOkLab(l, a, b float64) OkLab

NewOkLab create a OkLab model from l,a,b values

func OkLabFromXYZ 

func OkLabFromXYZ(c XYZ) OkLab

OkLabFromXYZ create a OkLab model from x,y,z value of XYZ color space

func (OkLab) String 

func (ok OkLab) String() string

String returns a formatted string representation of OkLab color.

func (OkLab) ToARGB 

func (ok OkLab) ToARGB() ARGB

ToARGB convert OkLab model to ARGB color model.

func (OkLab) ToOkLch 

func (ok OkLab) ToOkLch() OkLch

ToOkLch convert OkLab model to ToOkLch color model.

func (OkLab) ToXYZ 

func (ok OkLab) ToXYZ() XYZ

ToXYZ convert OkLab model to XYZ color model.

func (OkLab) Values 

func (ok OkLab) Values() (float64, float64, float64)

Values returns L, a, b values of OkLab Model

type OkLch 

type OkLch struct {
	// Lightness is the perceptual lightness component, ranging from 0 (black)
	// to 100 (reference white).
	Lightness float64 `json:"lightness"`
	// Chroma is the chroma (color intensity or saturation) component, ranging
	// from 0 (neutral gray) to 100 (maximum vividness).
	Chroma float64 `json:"chroma"`
	// Hue is the hue angle in degrees, ranging from 0 to 360, where 0° = red,
	// 120° = green, and 240° = blue.
	Hue float64 `json:"hue"`
}

OkLch represents a color in the OkLCh color space, a cylindrical transformation of OkLab designed for perceptual uniformity and intuitive manipulation of lightness, chroma, and hue.

OkLCh provides a more perceptually uniform representation than RGB and improves color blending, interpolation, and prediction of hue and lightness. The model was introduced by Björn Ottosson in 2020.

func NewOkLch 

func NewOkLch(l, c, h float64) OkLch

NewOkLch create a OkLch model from l,c,h values

func OkLchFromOkLab 

func OkLchFromOkLab(ok OkLab) OkLch

OkLchFromOkLab create a OkLch model from a OkLab model

func (OkLch) String 

func (ok OkLch) String() string

String returns a formatted string representation of OkLch color.

func (OkLch) ToARGB 

func (ok OkLch) ToARGB() ARGB

ToARGB convert OkLab model to ARGB color model.

func (OkLch) ToOkLab 

func (ok OkLch) ToOkLab() OkLab

ToOkLab convert OkLch model to OkLab color model.

func (OkLch) ToXYZ 

func (ok OkLch) ToXYZ() XYZ

ToXYZ convert OkLab model to XYZ color model.

func (OkLch) Values 

func (ok OkLch) Values() (float64, float64, float64)

Values returns L, a, b values of OkLab Model

type XYZ 

type XYZ struct {
	X float64 `json:"x"`
	Y float64 `json:"y"`
	Z float64 `json:"z"`
}

The XYZ color space, developed by the International Commission on Illumination (CIE) in 1931, is a mathematical model that represents all colors visible to the human eye based on three components: X, Y, and Z. It serves as a standard reference for color measurement and is widely used in various industries for color management and communication.

func NewXYZ 

func NewXYZ(x, y, z float64) XYZ

NewXYZ creates a color in XYZ model.

func (XYZ) LStar 

func (c XYZ) LStar() float64

LStar returns the L* value of L*a*b* (LabColor)

func (XYZ) Luminance 

func (c XYZ) Luminance() float64

Luminance returns the Y value of XYZColor

func (XYZ) RGBA 

func (c XYZ) RGBA() (r, g, b, a uint32)

RGBA implements the color.Color interface. Returns r, g, b, a values in the 0-65535 range.

func (XYZ) ToARGB 

func (c XYZ) ToARGB() ARGB

ToARGB converts c in XZY to ARGB color model.

func (XYZ) ToCam16 

func (c XYZ) ToCam16() Cam16

ToCam16 converts XYZ to color appearance model (Cam16)

func (XYZ) ToHct 

func (c XYZ) ToHct() Hct

ToHct convets XYZ to Hct (Hue, Chroma, Tone) model

func (XYZ) ToLCHab 

func (c XYZ) ToLCHab() LCHab

ToLCHab convets XYZ to LCHab color model

func (XYZ) ToLCHuv 

func (c XYZ) ToLCHuv() LCHuv

ToLCHuv convets XYZ to LCHuv color model

func (XYZ) ToLab 

func (c XYZ) ToLab() Lab

ToLab convets XYZ to CieLab color model

func (XYZ) ToLinearRGB 

func (c XYZ) ToLinearRGB() LinearRGB

ToLinearRGB converts c in XZY to LinearRGB color model.

func (XYZ) ToLuv 

func (c XYZ) ToLuv() Luv

ToLuv convets XYZ to CIELUV color model

func (XYZ) ToOkLab 

func (c XYZ) ToOkLab() OkLab

ToOkLab convets XYZ to OkLan color model

func (XYZ) Values 

func (c XYZ) Values() (float64, float64, float64)

Values returns x, y, z values of XYZColor

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