How PHP adjusts the size of pictures on the server side

This article mainly introduces the PHP implementation of the server-side adjustment of the image size of the method, an example of Imageresizer and loadimage operation of the image of the relevant skills, the need for friends can refer to the next

This article explains how PHP implements resizing images on the server side. Share to everyone for your reference. The specific analysis is as follows:

The resizing of the image on the server side is a lot more beneficial than the browser processing.
This article describes how PHP adjusts the image size on the server side.

The code consists of two parts:

①imageresizer () is used to process the image
②loadimage () 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), ' &amp ; w= ', $width, ' &h= ', $height; }?>

Usage:

Above code would is in a file called Image.php.//images would is displayed like This: