with large file, where imagerotate is missing, you can use, when possible "convert" command from ImageMagick. Here is a sample script.

<?php

error_reporting(E_ALL);

header("Content-type: image/png");

$file = 'images/test/imgp2498.jpg';

image_rotate_with_convert($file, 90);

function image_rotate_with_convert($file, $angle){
    passthru("convert -rotate $angle $file -");
}

?>