Can't Upload Image(article)

Controller.php

<?php
class Articles extends CI_Controller {

    var $session_user;

    function __construct() {
        parent::__construct();

        Utils::no_cache();
        if (!$this->session->userdata('logged_in')) {
            redirect(base_url('auth/login'));
            exit;
        }
        $this->session_user = $this->session->userdata('logged_in');

        $this->load->model('articlesModel');
    }
    function add(){
        $data['title'] = 'Buat Artikel';
        $data['session_user'] = $this->session_user;
        $this->load->library('upload');

        if(count($_POST)){
        $config['upload_path'] = './public/images/'; //path folder
        $config['allowed_types'] = 'jpg|png|jpeg'; //type yang dapat diakses bisa anda sesuaikan
        $config['encrypt_name'] = TRUE; //nama yang terupload nantinya

        $this->upload->initialize($config);
        if(!empty($_FILES['image']['name'])){
            if ($this->upload->do_upload('image'))
                {
                    $img = $this->upload->data();
                    $image=$img['file_name']; //Mengambil file name dari gambar yang diupload
                    $data['notif'] = $this->articlesModel->addArticles($this->session_user['users_id'],$image);
                }
                     
            }else{
                $data['notif'] = $this->articlesModel->addArticles($this->session_user['users_id']);
            }
        }

        $this->load->view('includes/header', $data);
        $this->load->view('dashboard/article_add', $data);
        $this->load->view('includes/footer', $data);
    }
}

Model.php

<?php
class ArticlesModel extends CI_Model{

	function __construct(){
		parent::__construct();
	}
  //addArticle
	function addArticles($author, $image = ''){
		$notif = array();

		$data = array(
				'article_id' => '',
				'author' => $author,
				'title' => $this->input->post('title'),
				'tags' => $this->input->post('tags'),
        'pic'  => $image,
				'contents' => $this->input->post('contents'),
				'is_posted' => $this->input->post('is_posted') ? : 0
			);
		$this->db->insert('articles', $data);

		if ($this->db->affected_rows() > 0) {
            $notif['message'] = 'Saved successfully';
            $notif['type'] = 'success';
            unset($_POST);
        } else {
            $notif['message'] = 'Something wrong !';
            $notif['type'] = 'danger';
        }
        return $notif;
	}
}

View.php

<form id="form_validation" method="POST">
   <div class="form-group form-float">
        <div class="form-line">
            <input type="text" class="form-control" name="title" value="<?php echo $this->input->post('title');?>" required>
            <label class="form-label">Judul</label>
        </div>
    </div>
    <!-- Tags Input -->
    <div class="form-group demo-tagsinput-area">
        <div class="form-line">
            <p style="color: #aaa">Tags</p>
            <input type="text" name="tags" size="150" class="form-control" data-role="tagsinput" value="<?php $this->input->post('tags');?>">
        </div>
    </div>
    <!-- #END# Tags Input -->
    <div class="form-group form-float">
        <div class="form-line">
            <textarea name="contents" cols="20" rows="7" class="form-control " required><?php echo $this->input->post('contents');?></textarea>
            <label class="form-label">Isi Artikel</label>
        </div>
    </div>
    <div class="form-group form-float">
        <div class="form-line">
            <p style="color: #aaa">Gambar</p><img src="" id="pic" style="max-height: 200px;" />
            <input type="file" class="form-control" id="imgInp" name="image" accept="image/png,image/jpg,image/jpeg" onchange="document.getElementById('pic').src = window.URL.createObjectURL(this.files[0])"/>
        </div>
    </div>
    
    <div class="form-group">
        <?php  
           $checked ='';
           if(count($_POST)){
               if($this->input->post('is_posted'))  $checked ='checked';
           }
           else $checked ='checked';
        ?>
        <input type="checkbox" id="checkbox" name="is_posted" value="1" <?php echo $checked;?>>
        <label for="checkbox">Terbitkan</label>
    </div>
    <button class="btn btn-primary waves-effect" type="submit">SIMPAN</button>
</form>