<?php

// auto rotates an image file based on exif data from camera
// if destination file is specified then it saves file there, otherwise it will display it to user
// note that images already at normal orientation are skipped (when exif data Orientation = 1)

if(!function_exists("gd_auto_rotate")){
    function gd_auto_rotate($original_file, $destination_file=NULL){
        
        $original_extension = strtolower(pathinfo($original_file, PATHINFO_EXTENSION));
        if(isset($destination_file) and $destination_file!=''){
            $destination_extension = strtolower(pathinfo($destination_file, PATHINFO_EXTENSION));
        }
        
        // try to auto-rotate image by gd if needed (before editing it)
        // by imagemagik it has an easy option
        if(function_exists("exif_read_data")){
            
            $exif_data = exif_read_data($original_file);
            $exif_orientation = $exif_data['Orientation'];
            
            // value 1 = normal ?! skip it ?!
            
            if($exif_orientation=='3'  or $exif_orientation=='6' or $exif_orientation=='8'){
                
                $new_angle[3] = 180;
                $new_angle[6] = -90;
                $new_angle[8] = 90;
                
                // load the image
                if($original_extension == "jpg" or $original_extension == "jpeg"){
                    $original_image = imagecreatefromjpeg($original_file);
                }
                if($original_extension == "gif"){
                    $original_image = imagecreatefromgif($original_file);
                }
                if($original_extension == "png"){
                    $original_image = imagecreatefrompng($original_file);
                }
                
                $rotated_image = imagerotate($original_image, $new_angle[$exif_orientation], 0);
                
                // if no destination file is set, then show the image
                if(!$destination_file){
                    header('Content-type: image/jpeg');
                    imagejpeg($rotated_image, NULL, 100);
                }
                        
                // save the smaller image FILE if destination file given
                if($destination_extension == "jpg" or $destination_extension=="jpeg"){
                    imagejpeg($rotated_image, $destination_file,100);
                }
                if($destination_extension == "gif"){
                    imagegif($rotated_image, $destination_file);
                }
                if($destination_extension == "png"){
                    imagepng($rotated_image, $destination_file,9);
                }
                
                imagedestroy($original_image);
                imagedestroy($rotated_image);
            
            }
        }
    }
}

?>