zacscott/class.Thumbnailer.php

## class.Thumbnailer.php
<?php

namespace \net\zeddev\util;

/**
 * A simple utility to dynamically create thumbnail images.  Images can be
 * stored on disk, or served on the fly (depending how constructed).  For
 * example:
 *
 *	$ondisk = new Thumbnailer('thumbnail/dir/path');
 *	$onfly = new Thumbnailer(); // i.e. no thumbnail directory
 *
 * Thumbnails can then be produced like so:
 *
 *	$inst->thumbit('my/image.jpg'); // see thumbit() for all parameters
 *
 * **NOTE:** This file is released as a stand-alone utility. The original
 * file and the associated unit test can be found on GitHub Gist -
 * [here](https://gist.github.com/zscott92/7655122).
 *
 * @author Zachary Scott <zscott.dev@gmail.com>
 */
class Thumbnailer {

	private $dir;

	/**
	 * @param $dir The thumbnail directory.  If `null` thumbnails are output
	 * directly,  which is handy if you want to serve thumbnails on the fly
	 * (or just don't have write permission).
	 */
	public function __construct($dir = null) {
		assert($dir == null || is_readable($dir));

		$this->dir = $dir;

	}

	// opens an image with GD based on the mime type
	private function readImage($file) {

		$size = getimagesize($file);

	    switch ($size["mime"]) {
	        case "image/jpeg":
	            return imagecreatefromjpeg($file); //jpeg file
	        case "image/gif":
	            return imagecreatefromgif($file); //gif file
			case "image/png":
				return imagecreatefrompng($file); //png file
		    default:
		        return false;
	    }

	}

	// export image as jpeg
	private function writeImage($img, $path = null) {
		assert($img != null);

		// add jpeg extension, if not already
		if ($path != null && !preg_match('/.jpg$/i', $path))
			$path = "$path.jpg";

		// export to jpeg
		imagejpeg($img,	$path, 90);

		return $path;

	}

	/**
	 * Creates a thumbnail of given size.
	 *
	 * @param $img The image to make a thumbnail of.
	 * @param $width The width of the produced thumbnail.  A value of < 0
	 * maintains aspect ration based on height.
	 * @param $height The height of hte produced thumbnail.  Again < 0 keeps
	 * aspect ratio based on width.
	 */
	public function thumbit($img, $width = 120, $height = 0) {
		assert(is_readable($img));
		assert($width > 0 || $height > 0);

		list($srcw, $srch) = getimagesize($img);

		// scale image height, keeping aspect ratio
		if ($width > 0 && $height < 1) { // scale x
			$height = ($width / $srcw) * $srch;
		} else if ($height > 0 && $width < 1) { // scale y
			$width = ($height / $srch) * $srcw;
		} // else scale both

		$thumb = imagecreatetruecolor($width, $height);
		$source = $this->readImage($img);

		// resize thumbnail
		imagecopyresized(
			$thumb, $source,
			0, 0, 0, 0,
			$width, $height, $srcw, $srch
		);

		// set path to save
		if ($this->dir == null) {
			$thumbPath = null;
		} else {
			$thumbPath = $this->dir.'/'.basename($img);
		}

		// export image
		$thumbPath = $this->writeImage($thumb, $thumbPath);
		imagedestroy($thumb);

		return $thumbPath;

	}

}

?>

## thumbnail.php
<?php

require_once dirname(__FILE__).'/code/class.Thumbnailer.php';

// handle form submission
if (isset($_POST['ThumbForm'])) {

	$t = new Thumbnailer(
		$_POST['thumb']
	);

	// create thumbnail image
	$thumbPath = $t->thumbit(
		$_POST['image'],
		$_POST['width'],
		$_POST['height']
	);

}

// form values
$image = isset($_POST['image']) ? $_POST['image'] : 'upload/path.jpg';
$thumb = isset($_POST['thumb']) ? $_POST['thumb'] : 'thumbs';
$width = isset($_POST['width']) ? $_POST['width'] : '120';
$height = isset($_POST['height']) ? $_POST['height'] : '0';

?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
	<title>Thumbnailer Test</title>
	<style type="text/css">
	input {
		display: block;
	}
	</style>
</head>
<body>
	<h1>Thumbnailer Test</h1>
	<?php

	// put thumbnail preview
	if (isset($thumbPath)) {
		echo "<a href='$image' target='_thumb'>";
		echo "<img src='$thumbPath'/>";
		echo "</a>\n";
	}

	?>
	<form action="thumbnail.php" method="post">

		<label for="image">Image path</label>
		<input type="text" name="image" value="<?php echo $image ?>"/>

		<label for="thumb">Thumbnail path</label>
		<input type="text" name="thumb" value="<?php echo $thumb ?>"/>

		<label for="width">Width</label>
		<input type="number" name="width" value="<?php echo $width ?>"/>

		<label for="height">Height</label>
		<input type="number" name="height" value="<?php echo $height ?>"/>

		<input type="submit" name="ThumbForm" value="Thumbit"/>

	</form>
</body>
</html>
	<?php

	namespace \net\zeddev\util;

	/**
	* A simple utility to dynamically create thumbnail images. Images can be
	* stored on disk, or served on the fly (depending how constructed). For
	* example:
	*
	* $ondisk = new Thumbnailer('thumbnail/dir/path');
	* $onfly = new Thumbnailer(); // i.e. no thumbnail directory
	*
	* Thumbnails can then be produced like so:
	*
	* $inst->thumbit('my/image.jpg'); // see thumbit() for all parameters
	*
	* NOTE: This file is released as a stand-alone utility. The original
	* file and the associated unit test can be found on GitHub Gist -
	* [here](https://gist.github.com/zscott92/7655122).
	*
	* @author Zachary Scott <zscott.dev@gmail.com>
	*/
	class Thumbnailer {

	private $dir;

	/**
	* @param $dir The thumbnail directory. If `null` thumbnails are output
	* directly, which is handy if you want to serve thumbnails on the fly
	* (or just don't have write permission).
	*/
	public function __construct($dir = null) {
	assert($dir == null \|\| is_readable($dir));

	$this->dir = $dir;

	}

	// opens an image with GD based on the mime type
	private function readImage($file) {

	$size = getimagesize($file);

	switch ($size["mime"]) {
	case "image/jpeg":
	return imagecreatefromjpeg($file); //jpeg file
	case "image/gif":
	return imagecreatefromgif($file); //gif file
	case "image/png":
	return imagecreatefrompng($file); //png file
	default:
	return false;
	}

	}

	// export image as jpeg
	private function writeImage($img, $path = null) {
	assert($img != null);

	// add jpeg extension, if not already
	if ($path != null && !preg_match('/.jpg$/i', $path))
	$path = "$path.jpg";

	// export to jpeg
	imagejpeg($img, $path, 90);

	return $path;

	}

	/**
	* Creates a thumbnail of given size.
	*
	* @param $img The image to make a thumbnail of.
	* @param $width The width of the produced thumbnail. A value of < 0
	* maintains aspect ration based on height.
	* @param $height The height of hte produced thumbnail. Again < 0 keeps
	* aspect ratio based on width.
	*/
	public function thumbit($img, $width = 120, $height = 0) {
	assert(is_readable($img));
	assert($width > 0 \|\| $height > 0);

	list($srcw, $srch) = getimagesize($img);

	// scale image height, keeping aspect ratio
	if ($width > 0 && $height < 1) { // scale x
	$height = ($width / $srcw) * $srch;
	} else if ($height > 0 && $width < 1) { // scale y
	$width = ($height / $srch) * $srcw;
	} // else scale both

	$thumb = imagecreatetruecolor($width, $height);
	$source = $this->readImage($img);

	// resize thumbnail
	imagecopyresized(
	$thumb, $source,
	0, 0, 0, 0,
	$width, $height, $srcw, $srch
	);

	// set path to save
	if ($this->dir == null) {
	$thumbPath = null;
	} else {
	$thumbPath = $this->dir.'/'.basename($img);
	}

	// export image
	$thumbPath = $this->writeImage($thumb, $thumbPath);
	imagedestroy($thumb);

	return $thumbPath;

	}

	}

	?>
	<?php

	require_once dirname(__FILE__).'/code/class.Thumbnailer.php';

	// handle form submission
	if (isset($_POST['ThumbForm'])) {

	$t = new Thumbnailer(
	$_POST['thumb']
	);

	// create thumbnail image
	$thumbPath = $t->thumbit(
	$_POST['image'],
	$_POST['width'],
	$_POST['height']
	);

	}

	// form values
	$image = isset($_POST['image']) ? $_POST['image'] : 'upload/path.jpg';
	$thumb = isset($_POST['thumb']) ? $_POST['thumb'] : 'thumbs';
	$width = isset($_POST['width']) ? $_POST['width'] : '120';
	$height = isset($_POST['height']) ? $_POST['height'] : '0';

	?>
	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
	<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
	<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
	<title>Thumbnailer Test</title>
	<style type="text/css">
	input {
	display: block;
	}
	</style>
	</head>
	<body>
	<h1>Thumbnailer Test</h1>
	<?php

	// put thumbnail preview
	if (isset($thumbPath)) {
	echo "<a href='$image' target='_thumb'>";
	echo "<img src='$thumbPath'/>";
	echo "</a>\n";
	}

	?>
	<form action="thumbnail.php" method="post">

	<label for="image">Image path</label>
	<input type="text" name="image" value="<?php echo $image ?>"/>

	<label for="thumb">Thumbnail path</label>
	<input type="text" name="thumb" value="<?php echo $thumb ?>"/>

	<label for="width">Width</label>
	<input type="number" name="width" value="<?php echo $width ?>"/>

	<label for="height">Height</label>
	<input type="number" name="height" value="<?php echo $height ?>"/>

	<input type="submit" name="ThumbForm" value="Thumbit"/>

	</form>
	</body>
	</html>