(PHP 4 >= 4.0.6, PHP 5, PHP 7)
imagecolorclosestalpha — 取锟斤拷锟斤拷指锟斤拷锟斤拷锟斤拷色锟斤拷透锟斤拷锟斤拷锟斤拷咏锟斤拷锟斤拷锟缴�
$image
, int $red
, int $green
, int $blue
, int $alpha
) : int
锟斤拷锟斤拷图锟斤拷锟缴拷锟斤拷锟斤拷锟街革拷锟斤拷锟� RGB 值锟皆硷拷
alpha 锟斤拷锟斤拷锟�"锟接斤拷"锟斤拷锟斤拷色锟斤拷
image锟斤拷图锟襟创斤拷锟斤拷锟斤拷(锟斤拷锟斤拷imagecreatetruecolor())锟斤拷锟截碉拷图锟斤拷锟斤拷源锟斤拷
red锟斤拷色锟缴分碉拷值锟斤拷
green锟斤拷色锟缴分碉拷值锟斤拷
blue锟斤拷色锟缴分碉拷值锟斤拷
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);
?>
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#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: 锟剿猴拷锟斤拷锟斤拷要 GD 2.0.1 锟斤拷锟斤拷甙姹�(锟狡硷拷 2.0.28 锟斤拷锟斤拷锟竭版本)锟斤拷