When you have a number of small images that appear on a page it makes sense to use CSS sprites to speed-up the rendering of your web page. This has two advantages: It reduces the number of HTTP requests a browser has to make to download the images on your page; Speeds up the rendering of the images and the web-page due to limits on the number of…

create-css-sprites.php

<?php

error_reporting(E_ALL);

$images_to_load = array(
	'C:/img-folder/01.jpg',
	'C:/img-folder/02.jpg',
	'C:/img-folder/03.jpg',
	'C:/img-folder/04.jpg',
	'C:/img-folder/05.jpg',
);

function load_jpeg($imgname, $width=100, $height=100)
{
    /* Attempt to open */
    $im = @imagecreatefromjpeg($imgname);

    /* See if it failed */
    if(!$im)
    {
        /* Create a black image */
        $im  = imagecreatetruecolor($width, $height);
        $bgc = imagecolorallocate($im, 255, 255, 255);
        $tc  = imagecolorallocate($im, 0, 0, 0);

        imagefilledrectangle($im, 0, 0, 150, 30, $bgc);

        /* Output an error message */
        imagestring($im, 1, 5, 5, 'Error loading ' . $imgname, $tc);
    }

    return $im;
}

function create_sprite($images_to_load, $path_to_file=NULL)
{
	if ($path_to_file  === NULL) header('Content-Type: image/jpeg');

	$imgs = array();

	$wrapimg = @imagecreatetruecolor(sizeof($images_to_load)*100, 100)
	      or die('Cannot Initialize new GD image stream');

	foreach ($images_to_load as $n => $_img)
	{
		$imgs[$n] = load_jpeg($_img);

		imagecopy($wrapimg, $imgs[$n], $n*100, 0, 0, 0, 100, 100);
	}

	// create (and save) sprite image
	imagejpeg($wrapimg, $path_to_file, 70);

	reset($images_to_load);

	foreach ($images_to_load as $n => $_img)
	{
		imagedestroy($imgs[$n]);
	}

	imagedestroy($wrapimg);
}

// ---------------------------------------------
create_sprite($images_to_load, __DIR__."/sprite.jpg");