pics/models/BestColor.php

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<?php
/*****************************************************************************
* BestColor.php
* Contains key class BestColor.
*
* !!! Licensing?
*****************************************************************************/
class BestColor
{
private $best;
public function __construct(Image $asset)
{
// Set fallback color.
$this->best = ['r' => 204, 'g' => 204, 'b' => 204]; // #cccccc
// We will be needing to read this...
if (!file_exists($asset->getPath()))
return;
// Try the arcane stuff again.
try
{
$image = new Imagick($asset->getPath());
$width = $image->getImageWidth();
$height = $image->getImageHeight();
// Sample six points in the image: four based on the rule of thirds, as well as the horizontal and vertical centre.
$topy = round($height / 3);
$bottomy = round(($height / 3) * 2);
$leftx = round($width / 3);
$rightx = round(($width / 3) * 2);
$centery = round($height / 2);
$centerx = round($width / 2);
// Grab their colours.
$rgb = [
$image->getImagePixelColor($leftx, $topy)->getColor(),
$image->getImagePixelColor($rightx, $topy)->getColor(),
$image->getImagePixelColor($leftx, $bottomy)->getColor(),
$image->getImagePixelColor($rightx, $bottomy)->getColor(),
$image->getImagePixelColor($centerx, $centery)->getColor(),
];
// We won't be needing this anymore, so save us some memory.
$image->clear();
$image->destroy();
}
// In case something does go wrong...
catch (ImagickException $e)
{
// Fall back to default color.
return;
}
// Process rgb values into hsv values
foreach ($rgb as $i => $color)
{
$colors[$i] = $color;
list($colors[$i]['h'], $colors[$i]['s'], $colors[$i]['v']) = self::rgb2hsv($color['r'], $color['g'], $color['b']);
}
// Figure out which color is the best saturated.
$best_saturation = $best_brightness = 0;
$the_best_s = $the_best_v = ['v' => 0];
foreach ($colors as $color)
{
if ($color['s'] > $best_saturation)
{
$best_saturation = $color['s'];
$the_best_s = $color;
}
if ($color['v'] > $best_brightness)
{
$best_brightness = $color['v'];
$the_best_v = $color;
}
}
// Is brightest the same as most saturated?
$this->best = ($the_best_s['v'] >= ($the_best_v['v'] - ($the_best_v['v'] / 2))) ? $the_best_s : $the_best_v;
}
public static function hex2rgb($hex)
{
return sscanf($hex, '%2X%2X%2X');
}
public static function rgb2hex($red, $green, $blue)
{
return sprintf('%02X%02X%02X', $red, $green, $blue);
}
public static function rgb2hsv($r, $g, $b)
{
$max = max($r, $g, $b);
$min = min($r, $g, $b);
$delta = $max - $min;
$v = round(($max / 255) * 100);
$s = ($max != 0) ? (round($delta / $max * 100)) : 0;
if ($s == 0)
{
$h = false;
}
else
{
if ($r == $max)
$h = ($g - $b) / $delta;
elseif ($g == $max)
$h = 2 + ($b - $r) / $delta;
elseif ($b == $max)
$h = 4 + ($r - $g) / $delta;
$h = round($h * 60);
if ($h > 360)
$h = 360;
if ($h < 0)
$h += 360;
}
return [$h, $s, $v];
}
/**
* Get a normal (light) background color as hexadecimal value (without hash prefix).
* @return color string
*/
public function hex()
{
$c = $this->best;
return self::rgb2hex($c['r'], $c['g'], $c['b']);
}
/**
* Get a 50% darker version of the best color as string.
* @param factor, defaults to 0.5
* @param alpha, defaults to 0.7
* @return rgba(r * factor, g * factor, b * factor, alpha)
*/
public function rgba($factor = 0.5, $alpha = 0.7)
{
$c = $this->best;
return 'rgba(' . round($c['r'] * $factor) . ', ' . round($c['g'] * $factor) . ', ' . round($c['b'] * $factor) . ', ' . $alpha . ')';
}
}