correctImageOrientation.php

<?php

/* 
 * Source code by WES of Stackoverflow 
 * https://stackoverflow.com/questions/3657023/how-to-detect-shot-angle-of-photo-and-auto-rotate-for-website-display-like-desk/18919355#18919355
 */


function correctImageOrientation($filename)
{
    if (function_exists('exif_read_data'))
    {
        $exif = exif_read_data($filename);
        if ($exif && isset($exif['Orientation']))
        {
            $orientation = $exif['Orientation'];
            if ($orientation != 1)
            {
                $img = imagecreatefromjpeg($filename);
                $deg = 0;
                switch ($orientation)
                {
                    case 3:
                        $deg = 180;
                    break;
                    case 6:
                        $deg = 270;
                    break;
                    case 8:
                        $deg = 90;
                    break;
                }
                if ($deg)
                {
                    $img = imagerotate($img, $deg, 0);
                }
                // then rewrite the rotated image back to the disk as $filename
                imagejpeg($img, $filename, 95);
            } // if there is some rotation necessary
            
        } // if have the exif orientation info
        
    } // if function exists
    
}