Изменение размера изображений в PHP

Класс для изменения размера изображений в PHP.
http://www.white-hat-web-design.co.uk/blog/resizing-images-with-php/

/*
* File: SimpleImage.php
* Author: Simon Jarvis
* Copyright: 2006 Simon Jarvis
* Date: 08/11/06
* Link: http://www.white-hat-web-design.co.uk/articles/php-image-resizing.php
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details:
* http://www.gnu.org/licenses/gpl.html
*
*/

class SimpleImage {

var $image;
var $image_type;

function load($filename) {

$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {

$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {

$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {

$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) {

if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {

imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {

imagepng($this->image,$filename);
}
if( $permissions != null) {

chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {

if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {

imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {

imagepng($this->image);
}
}
function getWidth() {

return imagesx($this->image);
}
function getHeight() {

return imagesy($this->image);
}
function resizeToHeight($height) {

$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}

function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}

function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}

function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}

}

//Чтобы вписать изображение в прямоугольник заданного размера я добавил еще в него функцию (вставлять перед закрывающей скобкой):


// Изменение размера изображения с сохранением соотношения сторон
// $width - максимальная ширина
// $height - максимальная высота
function scaleresize($width,$height) {
$swidth = $this->getWidth();
$sheight = $this->getheight();
if ($swidth / $width > $sheight / $height)
{
$this->resizeToWidth($width);
}
else
{
$this->resizeToHeight($height);
}
}