Struct LabColorSpace 

pub struct LabColorSpace {
    pub white_point: [f64; 3],
    pub black_point: [f64; 3],
    pub range: [f64; 4],
}

CIE Lab color space (ISO 32000-1 §8.6.5.4)

Fields

white_point: [f64; 3]

White point in CIE XYZ coordinates [Xw, Yw, Zw] Default is D50 standard illuminant

black_point: [f64; 3]

Black point in CIE XYZ coordinates [Xb, Yb, Zb]
Default is [0, 0, 0]

range: [f64; 4]

Range for a* and b* components [a_min, a_max, b_min, b_max] Default is [-100, 100, -100, 100]

Implementations

impl LabColorSpace

pub fn new() -> Self

Create a new Lab color space with default parameters

pub fn with_white_point(self, white_point: [f64; 3]) -> Self

Set the white point (CIE XYZ coordinates)

pub fn with_black_point(self, black_point: [f64; 3]) -> Self

Set the black point (CIE XYZ coordinates)

pub fn with_range(self, a_min: f64, a_max: f64, b_min: f64, b_max: f64) -> Self

Set the range for a* and b* components

pub fn d50() -> Self

Common D50 illuminant (default)

pub fn d65() -> Self

Common D65 illuminant

pub fn params_dictionary(&self) -> Dictionary

Build the Lab parameter dictionary (WhitePoint, optional BlackPoint/Range). Single source of the dict shape, shared by Self::to_pdf_array and the PageColorSpace bridge (impl From<&LabColorSpace> for PageColorSpace).

pub fn to_pdf_array(&self) -> Vec<Object>

Convert to PDF color space array

pub fn lab_to_xyz(&self, l: f64, a: f64, b: f64) -> [f64; 3]

Convert Lab values to CIE XYZ L* is in range [0, 100], a* and b* are typically in [-128, 127]

pub fn xyz_to_lab(&self, x: f64, y: f64, z: f64) -> [f64; 3]

Convert CIE XYZ to Lab values

pub fn lab_to_rgb(&self, l: f64, a: f64, b: f64) -> [f64; 3]

Convert Lab to approximate sRGB for display purposes This is a convenience method for visualization

pub fn rgb_to_lab(&self, r: f64, g: f64, b: f64) -> [f64; 3]

Convert sRGB to Lab for convenience

pub fn delta_e(&self, lab1: [f64; 3], lab2: [f64; 3]) -> f64

Calculate color difference (Delta E) between two Lab colors Uses CIE76 formula (Euclidean distance)

pub fn delta_e_2000(&self, lab1: [f64; 3], lab2: [f64; 3]) -> f64

Calculate perceptual color difference (Delta E 2000) More accurate for small color differences

Trait Implementations

impl Clone for LabColorSpace

fn clone(&self) -> LabColorSpace

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LabColorSpace

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LabColorSpace

fn default() -> Self

Returns the “default value” for a type.

impl From<&LabColorSpace> for PageColorSpace

fn from(cs: &LabColorSpace) -> Self

Bridge a typed LabColorSpace into a registrable colour space (ISO 32000-1 §8.6.5.4).

impl PartialEq for LabColorSpace

fn eq(&self, other: &LabColorSpace) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for LabColorSpace