imagecolorresolve

(PHP 4, PHP 5, PHP 7)

Get the index of the specified color or its closest possible alternative

int imagecolorresolve ( resource $image, int $red, int $green, int $blue )

This function is guaranteed to return a color index for a requested color, either the exact color or the closest possible alternative.

If you created the image from a file, only colors used in the image are resolved. Colors present only in the palette are not resolved.

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.

Returns:

Returns a color index.

Examples:

Using imagecoloresolve() to get colors from an image

<?php
// Load an image
$im = imagecreatefromgif('phplogo.gif');

// Get closest colors from the image
$colors = array();
$colors[] = imagecolorresolve($im, 255, 255, 255);
$colors[] = imagecolorresolve($im, 0, 0, 200);

// Output
print_r($colors);

imagedestroy($im);
?>

The above example will output something similar to:

Array
(
    [0] => 89
    [1] => 85
)