Create thumbnails for all images in a directory

This is a simple script to demonstrate using my image resizing function
. It scans the directory you place it in for any images, generates a thumbnail for each image, then outputs html to display the thumbnails as links to each image.

It requires php 5.1+ as it uses the Directory Iterator to get the files in the directory. If you’d like to see a version compatible with earlier versions of php leave a comment below.

For each file it checks that:

It is a jpeg, png or gif image (or at least has that file extension)
The filename doesn’t end in "_t.jpg" (as this is what is uses for naming the thumbnails)

Download from GitHub.
It then checks if a thumbnail exists with the same name and if one doesn’t (or the image file has been modified more recently) it attempts to create a thumbnail and save it in the current directory with the same name as the image, but with "_t.jpg" at the end of the name.

It pretty simple and meant more as an example for the resizing function, but would be quite easy to extend to show the image in the page with links to the previous and next image for example.

The code below needs the image resizing function to work which needs to be in the same directory. You can copy and paste or download both in a zip.

index.php

<?php

// thumbnail configuration
$thumb_width = 75;
$thumb_height = 75;
$thumb_method = 'crop';
$thumb_bgColour = null;//array(255,255,240);
$thumb_quality = 60;

// Let script run for as long as it needs to when creating thumbnails.
// Some web hosts won't let you use this function. In that case you'll need
// to comment it out and just refresh the script until it has thumbnailed all the images.
set_time_limit(0);

// include the thumbnail function
require_once dirname(__FILE__) . '/paGdThumbnail.php';

// get the path to the current directory
$path = dirname(__FILE__);

// get the url for the images
$path_info = pathinfo($_SERVER['SCRIPT_NAME']);
$url = $path_info['dirname'];

// create an array to store image names in.
$images = array();

$dir = new DirectoryIterator($path);

/*
 Loop through the directory, finding all images that aren't thumbnails.
 For each image:
	- if it doesn't already have a thumbnail, or the thumbnail is older than the image,
		create a thumbnail.
	- get info about the image
	- add the image to our images array
*/
foreach( $dir as $entry ){
	if( $entry->isFile() ){
		if( preg_match('#^(.+?)(_t)?.(jpg|gif|png)#i', $entry->getFilename(), $matches) ){

			list( ,$name, $is_a_thumb, $extension) = $matches;

			// if its not a thumbnail
			if( !$is_a_thumb ){
				// does a valid thumbnail exist?
				$has_thumb = false;
				$thumb_file = $path . '/' . $matches[1] . '_t.jpg';
				if( file_exists($thumb_file) && filemtime($thumb_file) > filemtime($entry->getPathname()) ){
					$has_thumb = true;
				}
				else{
					// no thumbnail, so we shall create one!

					// create a gd image. reading the contents of the image file into a string, then
					// using imagecreatefromstring saves having to check the filetype and which 
					// imagecreatefrom(jpeg/gif/png) function to use
					$image = imagecreatefromstring(file_get_contents($entry->getPathname()));

					if( $image ){
						// create the thumbnail
						$thumb = paGdThumbnail($image, $thumb_width, $thumb_height, $thumb_method, $thumb_bgColour);
						// free the image resource
						imagedestroy($image);
						if( $thumb ){
							// save the thumbnail
							if( imagejpeg($thumb, $thumb_file, $thumb_quality) ){
								$has_thumb = true;
							}
							// free the memory used by the thumbnail image
							imagedestroy($thumb);
						}
					}
				}
				if( $has_thumb ){
					$images[$entry->getFilename()] = $name;
				}
			}
		}
	}
}

// sort the images array so always in the same order
ksort($images);

// end or processing, now display the gallery
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>Thumbnails :p</title>
<style type="text/css">
<!--
#thumbs{
	position: relative;
}

#thumbs div{
	float: left;
	width: <?php echo $thumb_width + 30?>px;
	height: <?php echo $thumb_height + 30?>px;
	text-align: center;
}

#thumbs a:link img, #thumbs a:visited img{
	border: 1px solid #acacac;
	padding: 5px;
}

#thumbs a:hover img{
	border: 1px solid black;
}

-->
</style>
</head>
<body>
<div id="thumbs">
<?php foreach( $images as $imagename => $name ){ ?>

	<div>
		<a href="<?php echo $url . '/' . $imagename?>" title="Full Size"><img src="<?php echo $url . '/' . $name . '_t.jpg'?>"  /></a>
	</div>

<?php }?>
</div>
<div id="pb">
	powered by <a href="https://blog.samyapp.com/">a simple php image thumbnail script</a>
</div>
</body>
</html>

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<?php

// thumbnail configuration

$thumb_width = 75;

$thumb_height = 75;

$thumb_method = 'crop';

$thumb_bgColour = null;//array(255,255,240);

$thumb_quality = 60;

// Let script run for as long as it needs to when creating thumbnails.

// Some web hosts won't let you use this function. In that case you'll need

// to comment it out and just refresh the script until it has thumbnailed all the images.

set_time_limit(0);

// include the thumbnail function

require_once dirname(__FILE__) . '/paGdThumbnail.php';

// get the path to the current directory

$path = dirname(__FILE__);

// get the url for the images

$path_info = pathinfo($_SERVER['SCRIPT_NAME']);

$url = $path_info['dirname'];

// create an array to store image names in.

$images = array();

$dir = new DirectoryIterator($path);

Loop through the directory, finding all images that aren't thumbnails.

For each image:

- if it doesn't already have a thumbnail, or the thumbnail is older than the image,

create a thumbnail.

- get info about the image

- add the image to our images array

foreach( $dir as $entry ){

if( $entry->isFile() ){

if( preg_match('#^(.+?)(_t)?.(jpg|gif|png)#i', $entry->getFilename(), $matches) ){

list( ,$name, $is_a_thumb, $extension) = $matches;

// if its not a thumbnail

if( !$is_a_thumb ){

// does a valid thumbnail exist?

$has_thumb = false;

$thumb_file = $path . '/' . $matches[1] . '_t.jpg';

if( file_exists($thumb_file) && filemtime($thumb_file) > filemtime($entry->getPathname()) ){

$has_thumb = true;

}

else{

// no thumbnail, so we shall create one!

// create a gd image. reading the contents of the image file into a string, then

// using imagecreatefromstring saves having to check the filetype and which

// imagecreatefrom(jpeg/gif/png) function to use

$image = imagecreatefromstring(file_get_contents($entry->getPathname()));

if( $image ){

// create the thumbnail

$thumb = paGdThumbnail($image, $thumb_width, $thumb_height, $thumb_method, $thumb_bgColour);

// free the image resource

imagedestroy($image);

if( $thumb ){

// save the thumbnail

if( imagejpeg($thumb, $thumb_file, $thumb_quality) ){

$has_thumb = true;

}

// free the memory used by the thumbnail image

imagedestroy($thumb);

}

if( $has_thumb ){

$images[$entry->getFilename()] = $name;

}

// sort the images array so always in the same order

ksort($images);

// end or processing, now display the gallery

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<html>

<head>

<title>Thumbnails :p</title>

<!--

#thumbs{

position: relative;

}

#thumbs div{

float: left;

width: <?php echo $thumb_width + 30?>px;

height: <?php echo $thumb_height + 30?>px;

text-align: center;

}

#thumbs a:link img, #thumbs a:visited img{

border: 1px solid #acacac;

padding: 5px;

}

#thumbs a:hover img{

border: 1px solid black;

}

-->

</style>

</head>

<body>

<?php foreach( $images as $imagename => $name ){ ?>

<div>

<a href="<?php echo $url . '/' . $imagename?>" title="Full Size"><img src="<?php echo $url . '/' . $name . '_t.jpg'?>" /></a>

</div>

<?php }?>

</div>

</div>

</body>

</html>

2 responses

Andrew says:

February 22, 2009 at 3:28 pm

Hi I seen get this

Fatal error: Cannot instantiate non-existent class: directoryiterator in /homepages/6/

New to php so not sure why ! I guess its the directoryiterator thats causing the problem.

If you could help that would be fab.

Thanks in Advance
Andrew

Log in to Reply
- sam says:
  
  March 16, 2009 at 5:36 pm
  
  Hi Andrew,
  
  Apologies for the late reply. If you’re still interested, I think the problem is probably that your version of php does not have the directoryiterator class – this script needs php 5+ to work.
  
  If there’s any demand for a php4 version of this script I’ll modify the example when I have some time.
  
  Cheers,
  Sam
  
  Log in to Reply

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Create thumbnails for all images in a directory

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