imagecolorset

(PHP 4, PHP 5, PHP 7)

Set the color for the specified palette index

void imagecolorset ( resource $image, int $index, int $red, int $green, int $blue [, int $alpha = 0 ] )

This sets the specified index in the palette to the specified color. This is useful for creating flood-fill-like effects in palleted images without the overhead of performing the actual flood-fill.

Parameters:

image

An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().

index

An index in the palette.

red

Value of red component.

green

Value of green component.

blue

Value of blue component.

alpha

Value of alpha component.

Returns:

No value is returned.

Changelog:

5.4.0

The alpha parameter was added.

Examples:

imagecolorset() example

<?php
// Create a 300x100 image
$im = imagecreate(300, 100);

// Set the background to be red
imagecolorallocate($im, 255, 0, 0);

// Get the color index for the background
$bg = imagecolorat($im, 0, 0);

// Set the backgrund to be blue
imagecolorset($im, $bg, 0, 0, 255);

// Output the image to the browser
header('Content-Type: image/png');

imagepng($im);
imagedestroy($im);
?>