(PHP 4 >= 4.0.6, PHP 5, PHP 7)
imagecolorclosestalpha — Get the index of the closest color to the specified color + alpha
$image
, int $red
, int $green
, int $blue
, int $alpha
)
Returns the index of the color in the palette of the image which
is "closest" to the specified RGB value and
alpha
level.
image
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
red
Значення червоного компонента.
green
Значення зеленого компонента.
blue
Значення блакитного компонента.
alpha
A value between 0 and 127. 0 indicates completely opaque while 127 indicates completely transparent.
Returns the index of the closest color in the palette.
Приклад #1 Search for a set of colors in an image
<?php
// Start with an image and convert it to a palette-based image
$im = imagecreatefrompng('figures/imagecolorclosest.png');
imagetruecolortopalette($im, false, 255);
// Search colors (RGB)
$colors = array(
array(254, 145, 154, 50),
array(153, 145, 188, 127),
array(153, 90, 145, 0),
array(255, 137, 92, 84)
);
// Loop through each search and find the closest color in the palette.
// Return the search number, the search RGB and the converted RGB match
foreach($colors as $id => $rgb)
{
$result = imagecolorclosestalpha($im, $rgb[0], $rgb[1], $rgb[2], $rgb[3]);
$result = imagecolorsforindex($im, $result);
$result = "({$result['red']}, {$result['green']}, {$result['blue']}, {$result['alpha']})";
echo "#$id: Search ($rgb[0], $rgb[1], $rgb[2], $rgb[3]); Closest match: $result.\n";
}
imagedestroy($im);
?>
Наведений вище приклад виведе щось подібне до:
#0: Search (254, 145, 154, 50); Closest match: (252, 150, 148, 0). #1: Search (153, 145, 188, 127); Closest match: (148, 150, 196, 0). #2: Search (153, 90, 145, 0); Closest match: (148, 90, 156, 0). #3: Search (255, 137, 92, 84); Closest match: (252, 150, 92, 0).
Зауваження: Ця функція потребує GD 2.0.1 або новішої (рекомендовано версію 2.0.28 або новішу).