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。