这篇文章主要介绍了PHP图片等比缩放类SimpleImage使用方法和使用实例分享,需要的朋友可以参考下

使用方法示例： 设定宽度，等比例缩放    代码如下: <?php    include('SimpleImage.php');    $image = new SimpleImage();    $image->load('picture.jpg');    $image->resizeToWidth(250);    $image->save('picture2.jpg');?> 设定高度，等比例缩放  代码如下: <?php    include('SimpleImage.php');    $image = new SimpleImage();    $image->load('picture.jpg');    $image->resizeToHeight(500);    $image->save('picture2.jpg');    $image->resizeToHeight(200);    $image->save('picture3.jpg');?> 按比例，缩放至50%  代码如下: <?php    include('SimpleImage.php');    $image = new SimpleImage();    $image->load('picture.jpg');    $image->scale(50);    $image->save('picture2.jpg');?> 缩放后直接输出到屏幕  代码如下: <?php    header('Content-Type: image/jpeg');    include('SimpleImage.php');    $image = new SimpleImage();    $image->load('picture.jpg');    $image->resizeToWidth(150);    $image->output();?>       使用例子：  代码如下: <?php include("SimpleImage.php");//图片处理类在下面   $url="http://f3.v.veimg.cn/meadincms/1/2013/0703/20130703100937552.jpg"; $picfile = down($url);//下载图片（下载图片的路径可以处理完成后清空，这里未进行处理） $res = new SimpleImage();//图片处理实例 $res = $res->load($picfile); $tmpfile = tempfile().'.jpg';//创建一个路径文件用来保存图片 $width = '30';//设定图片的宽度 $res->resizeToWidth($width); $res->save($tmpfile);//把处理后的图片保存（无.jpg后缀） //这里总共产生了3个文件，一个是下载的图片文件，一个是临时文件，最后一个是处理的图片文件。需要优化清理掉前两个文件。         function down($url) {         $http = array();         $header = "http://f3.v.veimg.cn";         if ($header) {             $http['header'] = $header;         }           $http['timeout'] = 50;           $ctx = stream_context_create(array(             'http' => $http,         ));          $content = @file_get_contents($url, 0, $ctx);         sleep(1);           if (!$content) {             return false;         }           $tmpfile = tempfile();           file_put_contents($tmpfile, $content);           return $tmpfile; }   function tempfile() {         $path = dirname(__FILE__);         $path .= '/spider/' . date('Ymd') . '/'.date('His').'-' . (int)(time() / 300);           if (!file_exists($path)) {             mkdir($path, 0777, true);         }           do {             $file = $path . '/' . dechex(mt_rand());         }         while (file_exists($file));           touch($file);           return $file; }         图片处理类源码（官网地址：http://www.white-hat-web-design.co.uk/blog/resizing-images-with-php/）：   代码如下: <?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);         }           if (!$this->image) {             return false;         }           return $this;     }       function save($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) {         if ($this->getWidth() < $width) {             $width = $this->getWidth();         }         $ratio = $width / $this->getWidth();         $height = $this->getheight() * $ratio;         $this-&g