imagecolorallocate

(PHP 4, PHP 5, PHP 7)

Allocate a color for an image

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

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

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:

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:

5.1.3

Returns FALSE if the allocation failed. Previously -1 was returned.

Examples:

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);
 
?>