PHP Dynamic Image generation script - create fast loading image gallaries

PHP Dynamic Image generation script

A simple script in PHP which generates less sized image on runtime. the script needs PHP GD library installed on the server.

• This will save the page loading time
• A large image with huge sized image can be scaled and MB size of image can be reduced
• Script can generate image in Large,medium,small and custom size
• This can be used to create simple PHP image gallaries
• Image name should be passed as base64 encoded

The below given script must be saved as image.php

<?php
ob_start();

function createImage( $upload, $newWidth =120)
{
if (!$info = getimagesize($upload) )
return false;

$aspect = $info[0] / $info[1];
$newHeight = round( $newWidth/$aspect );

//get image type
$mimetype=$info['2'];

//create image based on type
if( $mimetype == 2 )
$src = @imagecreatefromjpeg("$upload");
elseif( $mimetype == 1 )
$src = @imagecreatefromgif("$upload");
elseif( $mimetype == 3 )
$src = @imagecreatefrompng("$upload");

if ( !$src )
return false;
//die( "$newWidth $newHeight");
$tmp = @imagecreatetruecolor( $newWidth, $newHeight );
imagecopyresampled( $tmp, $src, 0, 0, 0, 0, $newWidth,
$newHeight, $info[0], $info[1] );
ob_end_flush();

//rendering image

header("Content-type: {$mimetype}");
if( $mimetype == 2 )
imagejpeg( $tmp );
elseif( $mimetype == 1 )
imagegif( $tmp );
elseif( $mimetype == 3 )
imagepng( $tmp );

imagedestroy( $src );
imagedestroy( $tmp );
return true;
}
// Function end


if( isset($_GET["imgsrc"]) && trim($_GET["imgsrc"]) != "" ){
$thumbnail_width=120; $thumbnailFlag=0;
$img_file=base64_decode(trim($_GET["imgsrc"]));

$resizedwidth=120;

$sourceFolder="images/";




if( is_file( $sourceFolder.$img_file ) ){

if( isset($_GET['size']) && strtolower( trim( $_GET['size'] )) == "large" ){
$resizedwidth=620;
}elseif( isset($_GET['size']) && strtolower( trim( $_GET['size'] )) == "medium" ){
$resizedwidth=400;
}elseif( isset($_GET['size']) && strtolower( trim( $_GET['size'] )) == "custom" && isset($_GET['wid']) && intval( $_GET['wid'] ) > $thumbnail_width ){
$resizedwidth=intval( $_GET['wid'] );
}else{
$thumbnailFlag=1;
$resizedwidth=$thumbnail_width;
}

$imgInfo=getimagesize($sourceFolder.$img_file);
if( intval( $imgInfo[0] ) < $resizedwidth && !$thumbnailFlag ){
$resizedwidth = intval( $imgInfo[0] );
}

createImage( $sourceFolder.$img_file , $resizedwidth);
}
}



?>

Save the above script as image.php




The script assumes, that all images are in "images" folder in root, You can modify it according to your needs.

To generate the images you should use like given below:

<img src="http://www.your_domain.com/image.php?imgsrc=<?php echo(base64_encode('myimage.jpg')) ?>&size=small" />

<img src="http://www.your_domain.com/image.php?imgsrc=<?php echo(base64_encode('myimage.jpg')) ?>&size=large" />

<img src="http://www.your_domain.com/image.php?imgsrc=<?php echo(base64_encode('myimage.jpg')) ?>&size=medium" />

<img src="http://www.your_domain.com/image.php?imgsrc=<?php echo(base64_encode('myimage.jpg')) ?>&size=custom&width=200" />

The image link looks some what like this:
http://www.YOUR_DOMAIN.com/image.php?imgsrc=SU1HXzQyMDVfMTM2MTY0OTQyMS5KUEc=&size=small

<img src="http://www.YOUR_DOMAIN.com/image.php?imgsrc=SU1HXzQyMDVfMTM2MTY0OTQyMS5KUEc=&size=small" />

Try this and post your comments :)

PHP GD library: http://www.php.net/manual/en/book.image.php