fjw / color-compare
A library for converting colors (Hex, RGB, HSL, CIELAB (LAB), DIN-99) and calculating color distances based on DIN-99.
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Requires
- php: >=7.2.0
Requires (Dev)
- phpunit/phpunit: ^8
- squizlabs/php_codesniffer: 3.4.2
- symfony/var-dumper: ^5.0@dev
This package is auto-updated.
Last update: 2024-12-05 12:52:09 UTC
README
ColorCompare is a library to convert colors from hex, RGB, HSL, CIE L*a*b* (LAB) and DIN-99 into one another and calculate color distances (human visual difference) using the DIN-99 methedology.
You can get the library from packagist:
composer require fjw/color-compare
How to use
You can get the DIN-99 visual difference (distance) of two colors easily:
use ColorCompare\Color; $color1 = new Color("#aaff05"); $color2 = new Color("#CCC"); $difference = $color1->getDifference($color2);
You can convert each format into one another:
use ColorCompare\Color; $color = new Color("#aaff05"); $hex = $color->getHex(); // just to show off, it already was Hex ;) $rgb = $color->getRgb(); // [ "r" => 170, "g" => 255, "b" => 5 ] $hsl = $color->getHsl(); // [ "h" => 80.4, "s" => 1.0, "l" => 0.51 ] $lab = $color->getLab(); // [ "L" => 91.72, "a" => -54.41, "b" => 87.65 ] $din99 = $color->getDin99(); // [ "L99" => 94.51, "a99" => -12.31, "b99" => 30.39 ]
You can create the color object by Hex, RGB, HSL and LAB:
use ColorCompare\Color; $color = new Color([ "h" => 300, "s" => 0.5, "l" => 1 ]); $hex = $color->getHex();
Visual Color Distance with DIN-99
DIN-99 differences, returned by Color::getDifference(), can better calculate the human visual difference than LAB with delta-E. There are also superior distance calculations like CIE94 or CIEDE2000 but these are complicated and need intensive calculations. With DIN-99 the calculation is done beforehand and needs less ressources. When your color is already converted into DIN-99 you can just calculate the euklidean distance and get the same quality.
sqrt(($c2["L99"] - $c1["L99"])**2 + ($c2["a99"] - $c1["a99"])**2 + ($c2["b99"] - $c1["b99"])**2);
This is a huge advantage! If you would like, per example, make a client side filter of colored products (or whatever) you can convert your data into DIN-99 on the server side and only need to do the easier euklidean calculation in your JavaScript.
Sources (german):
http://www.germancolorgroup.de/html/Vortr_02_pdf/GCG_%202002_%20Buering.pdf
https://de.wikipedia.org/wiki/DIN99-Farbraum
Example Code
Just run ./devserver.sh
if you have PHP-CLI and open http://localhost:8000
to see the difference calculation in action.