php auto rotate image code example

Example: php rotate image

After some INet searches and personal try-and-failures I succeed to rotate PNG images with preserving alpha channel transparency (semi transparency).

<?php
    $filename = 'YourFile.png';
    $rotang = 20; // Rotation angle
    $source = imagecreatefrompng($filename) or die('Error opening file '.$filename);
    imagealphablending($source, false);
    imagesavealpha($source, true);

    $rotation = imagerotate($source, $rotang, imageColorAllocateAlpha($source, 0, 0, 0, 127));
    imagealphablending($rotation, false);
    imagesavealpha($rotation, true);

    header('Content-type: image/png');
    imagepng($rotation);
    imagedestroy($source);
    imagedestroy($rotation);
?>