(PHP 4 >= 4.0.6, PHP 5, PHP 7)
imagecolorclosestalpha — ȡ����ָ������ɫ��������ӽ�����ɫ
$image
, int $red
, int $green
, int $blue
, int $alpha
) : int
����ͼ���ɫ������ָ���� RGB ֵ�Լ�
alpha �����"�ӽ�"����ɫ��
image��ͼ������(����imagecreatetruecolor())���ص�ͼ����Դ��
red��ɫ�ɷֵ�ֵ��
green��ɫ�ɷֵ�ֵ��
blue��ɫ�ɷֵ�ֵ��
alphaA value between 0 and 127. 0 indicates completely opaque while 127 indicates completely transparent.
Returns the index of the closest color in the palette.
Example #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);
?>
�������̵���������ڣ�
#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).
Note: �˺�����Ҫ GD 2.0.1 ����߰汾(�Ƽ� 2.0.28 �����߰汾)��