[FIXED] How can I brighten/darken an image in PHP?

Issue

I guess I should be able to use GD to brighten or darken an image in PHP but don't find any info on it. Isn't that possible?

Solution

You can use the imagefilter function provided by PHP5 and up.

bool imagefilter ( resource $image , int $filtertype [, int $arg1 [, int $arg2 [, int $arg3 [, int $arg4 ]]]] )

You should be using the IMG_FILTER_BRIGHTNESS with a value from -255 to 255 to brighten/darken the image.

PHP Manual

Example from the manual

<?php
$im = imagecreatefrompng('sean.png');

if($im && imagefilter($im, IMG_FILTER_BRIGHTNESS, 20))
{
    echo 'Image brightness changed.';

    imagepng($im, 'sean.png');
    imagedestroy($im);
}
else
{
    echo 'Image brightness change failed.';
}
?>

Answered By - Murf

Answer Checked By - Dawn Plyler (PHPFixing Volunteer)