imagecolorclosestalpha
(PHP 4 >= 4.0.6, PHP 5, PHP 7)
imagecolorclosestalpha — Get the index of the closest color to the specified color + alpha
Description
int imagecolorclosestalpha ( resource $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.
Parameters
`image` An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
red
Value of red component.
green
Value of green component.
blue
Value of blue component.
alpha
A value between 0 and 127. 0 indicates completely opaque while 127 indicates completely transparent.
The colors parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.
Return Values
Returns the index of the closest color in the palette.
Examples
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);
?>The above example will output something similar to:
#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).See Also
- imagecolorexactalpha() - Get the index of the specified color + alpha
- imagecolorclosest() - Get the index of the closest color to the specified color
- imagecolorclosesthwb() - Get the index of the color which has the hue, white and blackness
← imagecolorclosest
imagecolorclosesthwb →
? 1997–2017 The PHP Documentation GroupLicensed under the Creative Commons Attribution License v3.0 or later.
本文档系腾讯云开发者社区成员共同维护，如有问题请联系 cloudcommunity@tencent.com
