resize_jpg.php
codice:
<?php
if( isSet( $_GET["img"], $_GET["size"] ) ) {
	$imgSize = getimagesize( (string) $_GET["img"] );
	$imgX = $imgSize[0];
	$imgY = $imgSize[1];
	$newY = floor( ( $imgSize[1] * intval( $_GET["size"] ) ) / $imgSize[0] );
	header( "Content-type: image/jpg" );
	$img_original = imageCreateFromJpeg( $_GET["img"] );
	$img_final = imageCreateTrueColor( $_GET["size"], $newY );
	imageCopyResampled( $img_final, $img_original, 0, 0, 0, 0, $_GET["size"], $newY, $imgX, $imgY );
	imageJpeg( $img_final );
	imageDestroy( $img_original );
	imageDestroy( $img_final );
}
?>


file.html
codice:
[img]resize_jpg.php?size=80&img=Esempio.jpg[/img]