php 修改上传图片尺寸示例

为大家讲述一下 php修改上传图片的尺寸，感兴趣的小伙伴，下面一起跟随编程之家 jb51.cc的小编来看看吧。
经测试代码如下：

<?php
/**
 * 修改上传图片的尺寸
 *
 * @param 
 * @arrange (编程之家) jb51.cc
 **/
// This is the temporary file created by PHP
$uploadedfile = $_FILES['uploadfile']['tmp_name'];
 
// Create an Image from it so we can do the resize
$src = imagecreatefromjpeg($uploadedfile);
 
// Capture the original size of the uploaded image
list($width,$height)=getimagesize($uploadedfile);
 
// For our purposes,I have resized the image to be
// 600 pixels wide,and maintain the original aspect
// ratio. This prevents the image from being stretched
// or squashed. If you prefer some max width other than
// 600,simply change the $newwidth variable
$newwidth=600;
$newheight=($height/$width)*600;
$tmp=imagecreatetruecolor($newwidth,$newheight);
 
// this line actually does the image resizing,copying from the original
// image into the $tmp image
imagecopyresampled($tmp,$src,$newwidth,$newheight,$width,$height);
 
// now write the resized image to disk. I have assumed that you want the
// resized,uploaded image file to reside in the ./images subdirectory.
$filename = images/. $_FILES['uploadfile']['name'];
imagejpeg($tmp,$filename,100);
 
imagedestroy($src);
imagedestroy($tmp); // NOTE: PHP will clean up the temp file it created when the request
// has completed.


/***   代码来自编程之家 jb51.cc（jb51.cc）   ***/