Struct OklabColor

Namespace

Egami.Colors

Assembly

Egami.dll

An Oklab color (Björn Ottosson, 2020): a perceptual space built on linear sRGB, where equal distances look about equally different and hues stay put when lightness or chroma changes. CSS Color 4's oklab().

public readonly record struct OklabColor : IColorValue<OklabColor>, IEquatable<OklabColor>

Implements

IColorValue<OklabColor>

IEquatable<OklabColor>

Inherited Members

ValueType.Equals(object)

ValueType.GetHashCode()

ValueType.ToString()

object.Equals(object, object)

object.GetType()

object.ReferenceEquals(object, object)

Examples

// Color values in the models apps ask for, from and to pixels, and between each other.
Rgba8 orange = new(240, 128, 32, 255);
HslColor hsl = HslColor.From(orange);                          // hue 28°, saturation 0.87, lightness 0.53
LabColor lab = ColorConvert.Convert<HslColor, LabColor>(hsl);  // through XYZ
OklchColor oklch = OklchColor.From(orange);
YCbCrColor jpeg = YCbCrColor.From(orange);                     // BT.601 full range, as JPEG
YCbCrColor video = YCbCrColor.From(orange, YuvMatrix.Bt709, YuvRange.Limited);

// Color difference: CIEDE2000 on Lab, distance on Oklab.
double deltaE = lab.DeltaE2000(LabColor.From(new Rgba8(235, 130, 40, 255)));

// Whole rows at once, from any pixel type and encoding.
Rgba8[] pixels = [orange, new(10, 20, 30, 255)];
OklabColor[] row = new OklabColor[pixels.Length];
ColorConvert.FromPixels<Rgba8, OklabColor>(pixels, row);
ColorConvert.FromPixels<Rgba8, OklabColor>(pixels, row, ColorProfile.DisplayP3);   // the same pixels read as Display P3

Constructors

OklabColor(float, float, float)

An Oklab color (Björn Ottosson, 2020): a perceptual space built on linear sRGB, where equal distances look about equally different and hues stay put when lightness or chroma changes. CSS Color 4's oklab().

public OklabColor(float L, float A, float B)

Parameters

L float

Lightness, 0 for black to 1 for white.

A float

Green (negative) to red (positive), about −0.4 to 0.4.

B float

Blue (negative) to yellow (positive), about −0.4 to 0.4.

Examples

// Color values in the models apps ask for, from and to pixels, and between each other.
Rgba8 orange = new(240, 128, 32, 255);
HslColor hsl = HslColor.From(orange);                          // hue 28°, saturation 0.87, lightness 0.53
LabColor lab = ColorConvert.Convert<HslColor, LabColor>(hsl);  // through XYZ
OklchColor oklch = OklchColor.From(orange);
YCbCrColor jpeg = YCbCrColor.From(orange);                     // BT.601 full range, as JPEG
YCbCrColor video = YCbCrColor.From(orange, YuvMatrix.Bt709, YuvRange.Limited);

// Color difference: CIEDE2000 on Lab, distance on Oklab.
double deltaE = lab.DeltaE2000(LabColor.From(new Rgba8(235, 130, 40, 255)));

// Whole rows at once, from any pixel type and encoding.
Rgba8[] pixels = [orange, new(10, 20, 30, 255)];
OklabColor[] row = new OklabColor[pixels.Length];
ColorConvert.FromPixels<Rgba8, OklabColor>(pixels, row);
ColorConvert.FromPixels<Rgba8, OklabColor>(pixels, row, ColorProfile.DisplayP3);   // the same pixels read as Display P3

Properties

A

Green (negative) to red (positive), about −0.4 to 0.4.

public float A { get; init; }

Property Value

float

B

Blue (negative) to yellow (positive), about −0.4 to 0.4.

public float B { get; init; }

Property Value

float

L

Lightness, 0 for black to 1 for white.

public float L { get; init; }

Property Value

float

Methods

Distance(OklabColor)

Returns the Euclidean distance in Oklab, its color difference: about 0.02 is just noticeable.

public double Distance(OklabColor other)

Parameters

other OklabColor

The other color.

Returns

double

The distance.

From(Rgba8)

Returns the value of an sRGB pixel; alpha is ignored.

public static OklabColor From(Rgba8 color)

Parameters

color Rgba8

The pixel.

Returns

OklabColor

The value.

From(RgbaF32)

Returns the value of an sRGB pixel, whose channels may be outside 0..1; alpha is ignored.

public static OklabColor From(RgbaF32 color)

Parameters

color RgbaF32

The pixel.

Returns

OklabColor

The value.

FromXyz(XyzColor)

Returns the value for an XYZ color (D65, white Y = 1).

public static OklabColor FromXyz(XyzColor xyz)

Parameters

xyz XyzColor

The color.

Returns

OklabColor

The value; components may fall outside their usual range for colors outside sRGB.

IsCloseTo(OklabColor, float)

Returns whether every component of the two values differs by at most tolerance.

public bool IsCloseTo(OklabColor other, float tolerance = 0.0001)

Parameters

other OklabColor

The other value.

tolerance float

The largest difference allowed in a component.

Returns

bool

true if they are that close.

ToRgba8()

Returns the color as an opaque sRGB pixel, each channel clamped into range.

public Rgba8 ToRgba8()

Returns

Rgba8

The pixel.

ToRgbaF32()

Returns the color as an opaque sRGB pixel, unclamped, so colors outside sRGB keep channels outside 0..1.

public RgbaF32 ToRgbaF32()

Returns

RgbaF32

The pixel.

ToXyz()

Returns the color as XYZ (D65, white Y = 1).

public XyzColor ToXyz()

Returns

XyzColor

The color.