PHP Manual: imagecolorclosesthwb

function imagecolorclosesthwb(
    GdImage $image,
    int $red,
    int $green,
    int $blue
): int

Get the index of the color which has the hue, white and blackness nearest the given color.

image: A GdImage object, 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 an integer with the index of the color which has the hue, white and blackness nearest the given color.

Version	Description
8.0.0	`image` expects a GdImage instance now; previously, a valid `gd` resource was expected.

Example #1 Example of using imagecolorclosesthwb()

<?php
$im = imagecreatefromgif('php.gif');

echo 'HWB: ' . imagecolorclosesthwb($im, 116, 115, 152);
?>

The above example will output something similar to:

HWB: 33

imagecolorclosesthwb