Recupertion des images !!!

Bonjour j ss entraint de cree l'action edit de user ms mon prb est que ya prb de recupreration de image upload the user voici l'action edit :
public function edit($id = null) {

        if (!$id) {
            $this->Session->setFlash('Please provide a user id');
            $this->redirect(array('action'=>'index'));
        }

        $user = $this->User->findById($id);
        if (!$user) {
            $this->Session->setFlash('Invalid User ID Provided');
            $this->redirect(array('action'=>'index'));
        }

        if ($this->request->is('post') || $this->request->is('put')) {
            $this->User->id = $id;
            if ($this->request->data) {

                debug('image :'.$this->request->data['User']['Photo_file']['name']);

            $extension = strtolower(pathinfo($this->request->data['User']['Photo_file']['name'],PATHINFO_EXTENSION));
            debug('extension'.$extension);
            /*//debug($this->request->data['User']['Photo_file']['tmp_name']);
            if (!empty($this->request->data['User']['Photo_file']['tmp_name']) &&   in_array($extension,array('jpg','png','jpeg'))) {

                move_uploaded_file($this->request->data['User']['Photo_file']['tmp_name'],
                IMAGES . 'avatars' .DS . $this->User->id .'.'.$extension);

                $this->User->saveField('avatar',$extension);
                debug($this->User->saveField('avatar',$extension));

                $this->Session->setFlash(__('The user has been updated'));
                $this->redirect(array('action' => 'index'));

        }else if (!empty($this->request->data['User']['Photo_file']['tmp_name'])) {

            $this->Session->setFlash(__('Type de fichier innaccepter'));
            debug($this->User->saveField('avatar',$extension));

        }*/
            }else{
                $this->Session->setFlash(__('Unable to update your user.'));
            }
        }

        if (!$this->request->data) {
            $this->request->data = $user;
        }
}

la ligne
debug('image :'.$this->request->data['User']['Photo_file']['name']);

            $extension = strtolower(pathinfo($this->request->data['User']['Photo_file']['name'],PATHINFO_EXTENSION));
            debug('extension'.$extension);

            donne comme resultat :

            app\Controller\UsersController.php (line 117)

'image :i'
\app\Controller\UsersController.php (line 120)
'extension'