Filename includes Backslashes also with stripslashes

I have got a the following problem: I have create a simple Image Upload Process like this.

public function postImage($id){
    $filename = date('Y-m-d_H:i:s').".jpg";
    $note=Note::find($id);
    $destinationPath='/srv/www/htdocs/example.com/api/public/projects/'.$note->project_id.'/notes/'.$id."/images/";
    $file = Request::file('image');
    $file->move($destinationPath, $filename);
    $image = new Image;
    $image->filename='projects/'.$note->project_id."/notes/images/".$filename;
    $image->note_id=$id;
    $image->save();
    $result= $this->respondWithItem($image, new ImageTransformer);
    return $result;
}

When returning filename which is in this case path to file beginning from projects plus at the end the filename it always returns something like that projects/1/notes/images/2015-03-27_10:44:291.jpg I of course dont want to have backslashes in my response. I use a Transformer for that like this:

<?php namespace App\Http\Controllers;
    use Image;
    use League\Fractal\TransformerAbstract;
    class ImageTransformer extends TransformerAbstract
    {
        public function transform(Image $image){
            return [
                'id' => (int) $image->id,
                'filename' => $image->filename,
                'note_id' => $image->note_id,
                'updated_at' => strtotime((string)$image->updated_at),
                'created_at' => strtotime((string)$image->created_at)
            ];
        }
    }

I tried everything from str_replace to stripslashes on the filename but it did not work. Am I missing something I am doing wrong? When returning just the filename directly in the controller the response is correct.