Crate lab

Lab

Tools for converting RGB colors to L*a*b* measurements.

RGB colors, for this crate at least, are considered to be composed of u8 values from 0 to 255, while L*a*b* colors are represented by its own struct that uses f32 values.

Usage

Converting single values

To convert a single value, use one of the functions

• lab::Lab::from_rgb(rgb: &[u8; 3]) -> Lab
• lab::Lab::from_rgba(rgba: &[u8; 4]) -> Lab (drops the fourth alpha byte)
• lab::Lab::to_rgb(&self) -> [u8; 3]

extern crate lab;
use lab::Lab;

let pink_in_lab = Lab::from_rgb(&[253, 120, 138]);
// Lab { l: 66.639084, a: 52.251457, b: 14.860654 }

Converting multiple values

To convert slices of values

• lab::rgbs_to_labs(rgbs: &[[u8; 3]]) -> Vec<Lab>
• lab::labs_to_rgbs(labs: &[Lab]) -> Vec<[u8; 3]>
• lab::rgb_bytes_to_labs(bytes: &[u8]) -> Vec<Lab>
• lab::labs_to_rgb_bytes(labs: &[Lab]) -> Vec<u8>

extern crate lab;
use lab::rgbs_to_labs;

let rgbs = vec![
    [0xFF, 0x69, 0xB6],
    [0xE7, 0x00, 0x00],
    [0xFF, 0x8C, 0x00],
    [0xFF, 0xEF, 0x00],
    [0x00, 0x81, 0x1F],
    [0x00, 0xC1, 0xC1],
    [0x00, 0x44, 0xFF],
    [0x76, 0x00, 0x89],
];

let labs = rgbs_to_labs(&rgbs);

extern crate lab;
use lab::rgb_bytes_to_labs;

let rgbs = vec![
    0xFF, 0x69, 0xB6,
    0xE7, 0x00, 0x00,
    0xFF, 0x8C, 0x00,
    0xFF, 0xEF, 0x00,
    0x00, 0x81, 0x1F,
    0x00, 0xC1, 0xC1,
    0x00, 0x44, 0xFF,
    0x76, 0x00, 0x89,
];

let labs = rgb_bytes_to_labs(&rgbs);

These functions will use x86_64 AVX2 instructions if compiled to a supported target.

Minimum Rust version

Lab 0.7.0 requires Rust >= 1.31.0 for the chunks_exact slice method

Structs

LCh

Struct representing a color in cylindrical CIELCh color space

Lab

Struct representing a color in CIALab, a.k.a. L*a*b*, color space

Functions

labs_to_rgb_bytes

Lab to RGB conversion that returns RGB triples flattened into a Vec<u8>

labs_to_rgbs

Convenience function to map a slice of Lab values to RGB values in serial

rgb_bytes_to_labs

RGB to Lab conversion that operates on a flat &[u8] of consecutive RGB triples.

rgbs_to_labs

Convenience function to map a slice of RGB values to Lab values in serial