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。