automated-colors.php

<?php
require 'vendor/autoload.php';

/*
	Using https://github.com/thephpleague/color-extractor
		for library
	http://stackoverflow.com/questions/1855884/determine-font-color-based-on-background-color
		for brightness text
*/

use League\ColorExtractor\Client as ColorExtractor;


function show_album($path) {
	echo "<div style=\"padding: 1em; margin: 1em; display: inline-block;\"><img src=\"{$path}\" style='width: 200px;' /></div>";
}

function show_color($color) {
	if ( is_array($color) ) {
		foreach ($color as $value) {
			show_color($value);
		}
	} else {
		$text = find_text_color($color) ? '#000' : '#fff';
		echo "<div style=\"color: {$text}; background-color: {$color}; width: 100px; height: 100px; padding: 1em; margin: 1em; display: inline-block;\">{$color}</div>";
	}
}

function find_text_color($color) {
	$c = substr($color, 1);
	$r = (substr($c, 0, 2));
	$g = (substr($c, 2, 2));
	$b = (substr($c, 4, 2));

	$z = array($r, $g, $b);
	$vs = array_map(function($x){return hexdec($x);}, $z);

	$a = 1 - (0.299 * $vs[0] + 0.587 * $vs[1] + 0.114 * $vs[2]) / 255;
	return ($a < 0.5);
}

function extract_album_color($path) {
	$client = new ColorExtractor;

	$image = $client->loadJpeg($path);

	$palette = $image->extract(3);
	show_album($path);
	show_color($palette);
	echo "<br style='clear:both;' /><hr />";
}

/* See visual example here: http://adept.work/j http://adept.work/m  */

$albums = ['atn.jpg', 'cs.jpg', 'eb.jpg'];
foreach ($albums as $album) {
	extract_album_color($album);
}

?>