<?php

 class ImageResize

 {

     private $image;

     private $img_des;

     private $image_type;

     private $permissions;

     private $compression;

     /**

      * 构造函数

      * @param string $img_src     源图片

      * @param string $img_des     保存图片对象

      * @param int    $compression 压缩比率，范围0-100(0:压缩比最高，100：压缩比最低)

      * @param null   $permissions 改变文件模式

      *                            mode 参数由 4 个数字组成：

      *                            第一个数字永远是 0

      *                            第二个数字规定所有者的权限

      *                            第二个数字规定所有者所属的用户组的权限

      *                            第四个数字规定其他所有人的权限

      *                            1 - 执行权限，2 - 写权限，4 - 读权限

      */

     function __construct($img_src, $img_des = NULL, $compression = 75, $permissions = null)

     {

         $image_info = getimagesize($img_src);

         $this->img_des = $img_des;

         $this->image_type = $image_info[2];

         $this->compression = $compression;

         $this->permissions = $permissions;

         if ($this->image_type == IMAGETYPE_JPEG) {

             $this->image = ImageCreateFromJPEG($img_src);

         } elseif ($this->image_type == IMAGETYPE_GIF) {

             $this->image = ImageCreateFromGIF($img_src);

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

             $this->image = ImageCreateFromPNG($img_src);

         }

     }

     /**

      * 保存图片

      */

     function save()

     {

         if ($this->image_type == IMAGETYPE_JPEG) {

             imagejpeg($this->image, $this->img_des, $this->compression);

         } elseif ($this->image_type == IMAGETYPE_GIF) {

             imagegif($this->image, $this->img_des);

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

             imagepng($this->image, $this->img_des);

         }

         if ($this->permissions != null) {

             chmod($this->image, $this->compression);

         }

     }

     /**

      * 做为图片流直接输出

      */

     function output()

     {

         if ($this->image_type == IMAGETYPE_JPEG) {

             header('Content-Type: image/jpg');

             imagejpeg($this->image);

         } elseif ($this->image_type == IMAGETYPE_GIF) {

             header('Content-Type: image/gif');

             imagegif($this->image);

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

             header('Content-Type: image/png');

             imagepng($this->image);

         }

     }

     /**

      * 获取图片宽度

      * @return int 图片宽度

      */

     function getWidth()

     {

         return imagesx($this->image);

     }

     /*

      * 获取图片高度

      * @return int 图片高度

      */

     function getHeight()

     {

         return imagesy($this->image);

     }

     /**

      * 按照固定高度缩放图片

      * @param $height 需要改变大小的高度

      */

     function resizeToHeight($height)

     {

         $ratio = $height / $this->getHeight();

         $width = $this->getWidth() * $ratio;

         $this->resize($width, $height);

     }

     /**

      * 按照固定宽度缩放图片

      * @param $width 指定宽度

      */

     function resizeToWidth($width)

     {

         $ratio = $width / $this->getWidth();

         $height = $this->getheight() * $ratio;

         $this->resize($width, $height);

     }

     /**

      * 等比缩放图片

      * @param int $scale 缩放比例

      */

     function scale($scale)

     {

         $width = $this->getWidth() * $scale / 100;

         $height = $this->getheight() * $scale / 100;

         $this->resize($width, $height);

     }

     /**

      * 指定宽度和高度缩放图片

      * @param int $width  缩放宽度

      * @param int $height 缩放高度

      * @return 缩放后图片对象

      */

     function resize($width, $height)

     {

         $new_image = imagecreatetruecolor($width, $height);

         if ($this->image_type == IMAGETYPE_GIF || $this->image_type == IMAGETYPE_PNG) {

             $current_transparent = imagecolortransparent($this->image);

             if ($current_transparent != -1) {

                 $transparent_color = imagecolorsforindex($this->image, $current_transparent);

                 $current_transparent = imagecolorallocate($new_image, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);

                 imagefill($new_image, 0, 0, $current_transparent);

                 imagecolortransparent($new_image, $current_transparent);

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

                 imagealphablending($new_image, false);

                 $color = imagecolorallocatealpha($new_image, 0, 0, 0, 127);

                 imagefill($new_image, 0, 0, $color);

                 imagesavealpha($new_image, true);

             }

         }

         imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());

         $this->image = $new_image;

     }

 }

 ?>

 $image = new ImageResize($tmp_image_name, NULL, 100);

 $image->output();