imagecolorat
PHP function
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(PHP 4, PHP 5, PHP 7, PHP 8)
Get the index of the color of a pixel
Description
imagecolorat(GdImage $image, int $x, int $y): int|false
Returns the index of the color of the pixel at the specified location in the image specified by image.
If the image is a truecolor image, this function returns the RGB value of that pixel as integer. Use bitshifting and masking to access the distinct red, green and blue component values:
Parameters
xx-coordinate of the point.
yy-coordinate of the point.
Return Values
Returns the index of the color Falseforfailure.
Falseproblem
Changelog
| Version | Description |
|---|
Examples
Access distinct RGB values
php
<?php
$im = imagecreatefrompng("php.png");
$rgb = imagecolorat($im, 10, 15);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
var_dump($r, $g, $b);
?>The above example will output something similar to:
output
int(119)
int(123)
int(180)Human-readable RGB values using imagecolorsforindex()
php
<?php
$im = imagecreatefrompng("php.png");
$rgb = imagecolorat($im, 10, 15);
$colors = imagecolorsforindex($im, $rgb);
var_dump($colors);
?>The above example will output something similar to:
output
array(4) {
["red"]=>
int(119)
["green"]=>
int(123)
["blue"]=>
int(180)
["alpha"]=>
int(127)
}