php实现在服务器端调整图片大小的方法


            本文实例讲述了php实现在服务器端调整图片大小的方法。分享给大家供大家参考。具体分析如下：

在服务器端完成图片大小的调整，会比在浏览器的处理有很多的好处。 

本文介绍了PHP如何在服务器端调整图片大小。

代码包括两部分：

① imageResizer() is used to process the image

② loadimage() inserts the image url in a simpler format





<?php

 function imageResizer($url, $width, $height) {

  header('Content-type: image/jpeg');

  list($width_orig, $height_orig) = getimagesize($url);

  $ratio_orig = $width_orig/$height_orig;

  if ($width/$height > $ratio_orig) {

   $width = $height*$ratio_orig;

  } else {

   $height = $width/$ratio_orig;

  }

  // This resamples the image

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

  $image = imagecreatefromjpeg($url);

  imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

  // Output the image

  imagejpeg($image_p, null, 100);

 }

 //works with both POST and GET

 $method = $_SERVER['REQUEST_METHOD'];

 if ($method == 'GET') {

  imageResize($_GET['url'], $_GET['w'], $_GET['h']);

  } elseif ($method == 'POST') {

  imageResize($_POST['url'], $_POST['w'], $_POST['h']);

  }

 // makes the process simpler

 function loadImage($url, $width, $height){

  echo 'image.php?url=', urlencode($url) ,

  '&w=',$width,

  '&h=',$height;

 }

?>







用法：





//Above code would be in a file called image.php.

//Images would be displayed like this:

<img src="<?php loadImage('image.jpg', 50, 50) ?>" alt="" />







希望本文所述对大家的php程序设计有所帮助。