Empfindung - Quantify color 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:

toml [dependencies] empfindung = "0.2"

Example

```rust extern crate empfindung; extern crate lab;

use empfindung::cie00;

fn main() { let color_1 = lab::Lab { l: 38.972, a: 58.991, b: 37.138, };

let color_2 = lab::Lab {
    l: 54.528,
    a: 42.416,
    b: 54.497,
};

let empfindung = cie00::diff(color_1, color_2);
println!("The color difference is: {}", empfindung);

let color_1 = (
    38.972,
    58.991,
    37.138,
);
let color_2 = (
    54.528,
    42.416,
    54.497,
);

let delta_e = cie76::diff(color_1, color_2);
println!("The Euclidean distance is: {}", delta_e);
assert_eq!(28.601656, delta_e);

} ```

Crate Features

The crate defines lab feature which is enabled by default. That feature adds dependency on the lab crate allowing the functions to take lab::Lab arguments. Furthermore, without it diff_rgb functions as well as DE2000 structure won’t be provided (the latter is deprecated anyway though).

Chances are that other part of a project depend on lab crate if it works on L*a*b* colours space in which case disabling the lab feature won’t bring any benefit but it may still be beneficial in cases where lab crate is not used anywhere else (e.g. because a different colour conversion libraries are used) or this crate somehow falls behind in its version specification for the lab crate (though at the moment that can only happen if lab release version 1.0).

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.

Migrating from to empfindung can be performed by using use declaration with an alias:

rust use empfindung as delta_e;

or changing the paths using delta_e crate name to use empfindung instead. In particular, if use delta_e::DE2000; declaration was used, it’s enough to change it to the following without having to touch the rest of the code:

rust 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

Empfindung is released under the MIT license, See LICENSE file.