Empfindung - Quantify colour differences in Rust

Empfindung is a library providing implementations of colour difference algorithms. Specifically, distances based on L*a*b* colour space often referred to as ΔE*. (This is also where the package gets its name. The ‘E’ stands for German ‘Empfindung’).

The crate provides CIEDE2000, CIE94, CIE76 and CMC l:c implementations.

Installation

If you're using Cargo, just add DeltaE to your Cargo.toml:

[dependencies]
empfindung = "0.2"

Example

use empfindung::cie00;

fn main() {
    let colour_1 = lab::Lab { l: 38.972, a: 58.991, b: 37.138 };
    let colour_2 = lab::Lab { l: 54.528, a: 42.416, b: 54.497 };

    let empfindung = cie00::diff(colour_1, colour_2);
    println!("The colour difference is: {}", empfindung);

    let colour_1 = ( 38.972, 58.991, 37.138 );
    let colour_2 = ( 54.528, 42.416, 54.497 );

    let delta_e = cie76::diff(colour_1, colour_2);
    println!("The Euclidean distance is: {}", delta_e);
    assert_eq!(28.601656, delta_e);

    let colour_1 = rgb::RGB::<u8>::new(234, 76, 76);
    let colour_2 = rgb::RGB::<u8>::new(76, 187, 234);
    let delta_e = cie00::diff(colour_1, colour_2);
    println!("The CIEDE200 colour difference is: {}", delta_e);
    assert_eq!(58.90164, delta_e);
}

Crate Features

The crate defines lab and rgb features which are enabled by default. The former adds dependency on the lab crate and allows functions to take lab::Lab arguments. The latter adds dependency on rgb crate and further allows functions to take rgb::RGB<u8> arguments.

About

This crate was originally written by Elliot Jackson and later forked by Michał Nazarewicz after long inactivity. Aside from the package name change, it is a drop-in replacement for the delta_e create.

A quick migrating from to empfindung can be performed via use declaration as follows:

use empfindung as delta_e;

or changing the paths to use the new crate name. In particular, if use delta_e::DE2000; declaration is used, it’s enough to replace it by the following without having to touch the rest of the code:

use empfindung::DE2000;  // was use delta_e::DE2000;

Having said that, the DE2000 structure is now deprecated and it’s better to use empfindung::cie00::diff directly.

License