The highest tagged major version is
Documentation
¶
Index ¶
- Constants
- Variables
- func Delinearized(component float64) uint8
- func Delinearized3(x, y, z float64) (uint8, uint8, uint8)
- func IsBlue(hue float64) bool
- func IsCyan(hue float64) bool
- func IsYellow(hue float64) bool
- func LabFunc(t float64) float64
- func LabInvFunc(ft float64) float64
- func Linearized(component uint8) float64
- func Linearized3(x, y, z uint8) (float64, float64, float64)
- func LstarFromY(y float64) float64
- func YFromLstar(lstar float64) float64
- type ARGB
- func ARGBFromHex(hex string) (ARGB, error)
- func ARGBFromHexMust(hex string) ARGB
- func ARGBFromInterface(color color.Color) ARGB
- func ARGBFromLinRGB(r, g, b float64) ARGB
- func ARGBFromLstar(lstar float64) ARGB
- func ARGBFromRGB(r, g, b uint8) ARGB
- func ARGBFromXYZ(x, y, z float64) ARGB
- func NewARGB(a, r, g, b uint8) ARGB
- func (c ARGB) Alpha() uint8
- func (c ARGB) AnsiBg(text string) string
- func (c ARGB) AnsiFg(text string) string
- func (c ARGB) Blue() uint8
- func (c ARGB) Green() uint8
- func (c ARGB) HexARGB() string
- func (c ARGB) HexRGB() string
- func (c ARGB) HexRGBA() string
- func (c ARGB) LStar() float64
- func (c ARGB) MarshalText() ([]byte, error)
- func (c ARGB) RGBA() (uint32, uint32, uint32, uint32)
- func (c ARGB) Red() uint8
- func (c ARGB) String() string
- func (c ARGB) ToARGB() ARGB
- func (c ARGB) ToCam() *Cam16
- func (c ARGB) ToHct() Hct
- func (c ARGB) ToLab() Lab
- func (c ARGB) ToXYZ() XYZ
- func (c *ARGB) UnmarshalText(text []byte) error
- func (c ARGB) Values() (uint8, uint8, uint8, uint8)
- type Cam16
- func Cam16FromJch(j, c, h float64) *Cam16
- func Cam16FromJchInEnv(j, c, h float64, env *Environmnet) *Cam16
- func Cam16FromUcs(jstar, astar, bstar float64) *Cam16
- func Cam16FromUcsInEnv(jstar, astar, bstar float64, env *Environmnet) *Cam16
- func Cam16FromXyzInEnv(xyz XYZ, env *Environmnet) *Cam16
- func NewCam16(hue, chroma, j, q, m, s, jstar, astar, bstar float64) *Cam16
- type Environmnet
- type Hct
- func (h Hct) Hash() uint64
- func (h *Hct) InViewingConditions(env *Environmnet) Hct
- func (h Hct) IsBlue() bool
- func (h Hct) IsCyan() bool
- func (h Hct) IsYellow() bool
- func (h Hct) RGBA() (uint32, uint32, uint32, uint32)
- func (h Hct) String() string
- func (h Hct) ToARGB() ARGB
- func (h Hct) ToCam() *Cam16
- func (h Hct) ToHct() Hct
- func (h Hct) ToLab() Lab
- func (h Hct) ToXYZ() XYZ
- type Lab
- func (a Lab) DistanceSquared(b Lab) float64
- func (c Lab) LStar() float64
- func (c Lab) LuminanceY() float64
- func (c Lab) RGBA() (uint32, uint32, uint32, uint32)
- func (c Lab) ToARGB() ARGB
- func (c Lab) ToCam() *Cam16
- func (c Lab) ToHct() Hct
- func (c Lab) ToLab() Lab
- func (c Lab) ToXYZ() XYZ
- func (c Lab) Values() (float64, float64, float64)
- type OkLab
- type XYZ
Constants ¶
const ( // Threshold for linear vs. nonlinear transition. [Reference] // // [Reference]: http://www.brucelindbloom.com/index.html?LContinuity.html LabFuncE float64 = 216.0 / 24389.0 // Constant used for linear approximation. [Reference] // // [Reference]: http://www.brucelindbloom.com/index.html?LContinuity.html LabFuncK float64 = 24389.0 / 27.0 )
const Brightest = uint8(0xFF) // 255
Brightest is the max value of uint8 color
Variables ¶
var ( Cat16Matrix = num.NewMatrix3( 0.401288, 0.650173, -0.051461, -0.250268, 1.204414, 0.045854, -0.002079, 0.048952, 0.953127, ) Cat16InvMatrix = num.NewMatrix3( 1.86206786, -1.01125463, 0.14918678, 0.38752654, 0.62144744, -0.00897399, -0.0158415, -0.03412294, 1.04996444, ) )
var ( SRGB_TO_XYZ = num.NewMatrix3( 0.41233895, 0.35762064, 0.18051042, 0.2126, 0.7152, 0.0722, 0.01932141, 0.11916382, 0.95034478, ) XYZ_TO_SRGB = num.NewMatrix3( 3.2413774792388685, -1.5376652402851851, -0.49885366846268053, -0.9691452513005321, 1.8758853451067872, 0.04156585616912061, 0.05562093689691305, -0.20395524564742123, 1.0571799111220335, ) // The white most point of XYZ to sRGB color space WhitePointD65 = num.NewVector3(95.047, 100.0, 108.883) CriticalPlanes = []float64{}/* 255 elements not displayed */ )
var DefaultEnviroment = NewEnvironment((200/math.Pi)*YFromLstar(50)/100, 50, 2, false)
DefaultEnviroment returns the default sRGB-like viewing conditions.
var LinrgbFromScaledDiscount = num.NewMatrix3(
1373.2198709594231, -1100.4251190754821, -7.278681089101213,
-271.815969077903, 559.6580465940733, -32.46047482791194,
1.9622899599665666, -57.173814538844006, 308.7233197812385,
)
var OkLabMatrix1 = num.NewMatrix3(
0.8189330101, 0.3618667424, -0.1288597137,
0.0329845436, 0.9293118715, 0.0361456387,
0.0482003018, 0.2643662691, 0.6338517070,
)
var OkLabMatrix1Inv = num.NewMatrix3(
1.2270138511, -0.5577999807, 0.2812561490,
-0.0405801784, 1.1122568696, -0.0716766787,
-0.0763812845, -0.4214819784, 1.5861632204,
)
var OkLabMatrix2 = num.NewMatrix3(
0.2104542553, 0.7936177850, -0.0040720468,
1.9779984951, -2.4285922050, 0.4505937099,
0.0259040371, 0.7827717662, -0.8086757660,
)
var OkLabMatrix2Inv = num.NewMatrix3(
0.9999999985, 0.3963377922, 0.2158037581,
1.0000000089, -0.1055613423, -0.0638541748,
1.0000000547, -0.0894841821, -1.2914855379,
)
var ScaledDiscountFromLinRGB = num.NewMatrix3(
0.001200833568784504, 0.002389694492170889, 0.0002795742885861124,
0.0005891086651375999, 0.0029785502573438758, 0.0003270666104008398,
0.00010146692491640572, 0.0005364214359186694, 0.0032979401770712076,
)
var YFromLinRGB = num.NewVector3(0.2126, 0.7152, 0.0722)
Functions ¶
func Delinearized ¶
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 Delinearized3 ¶
Delinearized3 is like Delinearized but takes 3 input and returns 3 output.
func LabFunc ¶
LabFunc is part of the conversion from XYZ to Lab color space. It applies a nonlinear transformation that approximates human vision perception.
func LabInvFunc ¶
LabInvFunc is the inverse of LabFunc, used when converting from Lab to XYZ. It reverses the nonlinear transformation.
func Linearized ¶
Linearized takes component (uint8) that represents R/G/B channel. Returns 0.0 <= output <= 1.0, color channel converted to linear RGB space
func Linearized3 ¶
Linearized3 is like Linearized but takes 3 input and returns 3 output.
func LstarFromY ¶
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 ¶
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 is an ARGB color packed into a uint32.
func ARGBFromHex ¶
ARGBFromHex parses a hex color string and returns a Color. Supports formats: #RGB, #RGBA, #RRGGBB, #RRGGBBAA
func ARGBFromHexMust ¶
ARGBFromHexMust parses a hex color string and returns a Color. Supports formats: #RGB, #RGBA, #RRGGBB, #RRGGBBAA
func ARGBFromLinRGB ¶
FromARGB creates a ARGB from individual 8-bit red, green, and blue components.
func ARGBFromLstar ¶
Converts an L* value to an ARGB representation. lstar is L* in L*a*b*. returns ARGB representation of grayscale color with lightness matching L*
func ARGBFromRGB ¶
FromARGB creates a ARGB from individual 8-bit red, green, and blue components.
func ARGBFromXYZ ¶
FromARGB creates a ARGB from xyz color space cordinates.
func (ARGB) AnsiBg ¶
AnsiBg wraps the given text with the ANSI escape sequence for the background color.
func (ARGB) AnsiFg ¶
AnsiFg wraps the given text with the ANSI escape sequence for the foreground color.
type Cam16 ¶
type Cam16 struct {
// Hue represents the hue of the color
Hue float64
// Chroma represents the colorfulness or color intensity, similar to
// saturation in HSL but more perceptually accurate
Chroma float64
// J represents the lightness of the color
J float64
// Q represents the brightness, which is the ratio of lightness to
// the white point's lightness
Q float64
// M represents the colorfulness of the color
M float64
// S represents the saturation, which is the ratio of chroma to
// the white point's chroma
S float64
// Jstar represents the CAM16-UCS J coordinate
Jstar float64
// Astar represents the CAM16-UCS a coordinate
Astar float64
// Bstar represents the CAM16-UCS b coordinate
Bstar float64
}
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 ¶
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 *Environmnet) *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 Cam16FromUcsInEnv ¶
func Cam16FromUcsInEnv(jstar, astar, bstar float64, env *Environmnet) *Cam16
func Cam16FromXyzInEnv ¶
func Cam16FromXyzInEnv(xyz XYZ, env *Environmnet) *Cam16
Cam16FromColorInEnv create a Cam16 color In specific ViewingConditions
func (*Cam16) Viewed ¶
func (c *Cam16) Viewed(vc *Environmnet) XYZ
Viewed converts a CAM16 color to an ARGB integer based on the given viewing conditions
type Environmnet ¶
type Environmnet 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
}
Environmnet 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, ) Environmnet
NewEnvironment creates a ViewingConditions instance with the specified parameters.
type Hct ¶
Hct represents a color in the HCT color space (Hue, Chroma, Tone). HCT provides a perceptually accurate color measurement system that can also accurately render what colors will appear as in different lighting environments.
func NewHct ¶
From creates an HCT color from the provided hue, chroma, and tone values.
hue: 0 <= hue < 360; invalid values are corrected. chroma: 0 <= chroma < ?; Chroma has a different maximum for any given hue and tone. tone: 0 <= tone <= 100; invalid values are corrected.
func (Hct) Hash ¶
Hash returns a uint64 hash representation of the HCT color. This is much more efficient than string-based hashing.
func (*Hct) InViewingConditions ¶
func (h *Hct) InViewingConditions(env *Environmnet) Hct
InViewingConditions translates a color into different ViewingConditions.
Colors change appearance. They look different with lights on versus off, the same color, as in hex code, on white looks different when on black. This is called color relativity, most famously explicated by Josef Albers in Interaction of Color.
In color science, color appearance models can account for this and calculate the appearance of a color in different settings. HCT is based on CAM16, a color appearance model, and uses it to make these calculations.
See ViewingConditions.Make for parameters affecting color appearance.
type Lab ¶
type Lab struct {
L, A, B float64
}
func (Lab) DistanceSquared ¶
DistanceSquared returns square of distance between two color
Source Files