imagecolorallocate

(PHP 4, PHP 5, PHP 7, PHP 8)

imagecolorallocate — Allocate a color for an image

Description

imagecolorallocate(
    GdImage $image,
    int $red,
    int $green,
    int $blue
): int|false

Returns a color identifier representing the color composed of the given RGB components.

imagecolorallocate() must be called to create each color that is to be used in the image represented by image.

Note:
The first call to imagecolorallocate() fills the background color in palette-based images - images created using imagecreate().

Parameters

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.

These parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.

Return Values

A color identifier or false if the allocation failed.

Warning

This function may return Boolean false, but may also return a non-Boolean value which evaluates to false. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

Changelog

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

Examples

Example #1 imagecolorallocate() example

<?php

$im = imagecreate(100, 100);

// sets background to red
$background = imagecolorallocate($im, 255, 0, 0);

// sets some colors
$white = imagecolorallocate($im, 255, 255, 255);
$black = imagecolorallocate($im, 0, 0, 0);

// hexadecimal way
$white = imagecolorallocate($im, 0xFF, 0xFF, 0xFF);
$black = imagecolorallocate($im, 0x00, 0x00, 0x00);

?>