<?php

//get the thumbnail width and length

$widthThumb=$_REQUEST["w"];

$lengthThumb=$_REQUEST["l"];

//get the image source

$filePath=$_REQUEST["fileName"];

//extract the width, length of the image

list($widthImage, $lengthImage, $fileType, $fileAttr) = getimagesize($filePath);

//check if file type if gif(=1), jpg(=2) or png(=3)

//if(($fileType!=1) || ($fileType!=2) || ($fileType!=3)) die("File type should be GIF, JPG, or PNG= ".$fileType.": ".($fileType==1));

//compute the final ratio

$widthRatio=$widthImage/$widthThumb;

$lengthRatio=$lengthImage/$lengthThumb;

if($widthRatio<1)$widthRatio=1;

if($lengthRatio<1)$lengthRatio=1;

if($widthRatio<$lengthRatio)$ratio=$widthRatio;

else $ratio=$lengthRatio;

//compute the thumbnails final dimension and offset on the main image

$widthFinal=$widthThumb*$ratio;

$lengthFinal=$lengthThumb*$ratio;

$offSetX=(int)(($widthImage-$widthFinal)/2);

//$offSetY=(int)(($lengthImage-$lengthFinal)/2);

//we try not to crop from the top

$offSetY=0;

//create the image instances

switch ($fileType){

        case 1:

                $srcImg= imagecreatefromgif("$filePath");

                break;

        case 2:

                $srcImg=imagecreatefromjpeg("$filePath");

                break;

        case 3:

                $srcImg=imagecreatefrompng("$filePath");

                break;

}

$destImg = imagecreatetruecolor($widthFinal, $lengthFinal);

//copy the image

imagecopy($destImg, $srcImg, 0, 0, $offSetX, $offSetY, $widthFinal, $lengthFinal);

//generate the thumbnail

$thumbImg=imagecreatetruecolor($widthThumb, $lengthThumb);

imagecopyresized($thumbImg, $destImg, 0, 0, 0, 0, $widthThumb, $lengthThumb, $widthFinal, $lengthFinal);

//output the image in png format

header('Content-Type: image/png');

imagepng($thumbImg);

//free the resourcses

imagedestroy($thumbImg);

imagedestroy($destImg);

imagedestroy($srcImg);

?>