Upload Model issues.

I am creating an upload script for my signed in users.

Libraries included: form, upload and image_lib.

From the controller I want to call upon the add image function, from the user model.
From the user model I want it to attempt to upload the file using the upload model.
And once the upload is complete I want the user model to create the thumbnails and add to database.

I get a dreaded The upload path does not appear to be valid. every single time.
I know the path works as I wrote echo $config['upload_path'] and copied the result in my browser and it took me to the directory.
Could someone shed some light on why I always get the error?

In my controller/profile.php I have:

PHP Code:

if($this->input->post())
        {                        
            if(!$this->user_model->add_image())
            {
                $data['errors'] = $this->upload->display_errors();
            }
} 


In my models/user_model.php I have:

PHP Code:

function add_image()
    {
        $config['upload_path'] = './public/images/';
        $config['allowed_types'] = 'gif|jpg|png';
        $config['max_size']    = '100';
        $config['max_width']  = '1024';
        $config['max_height']  = '768';

        if($this->upload_model->upload($config))
        {
            $data = $this->upload->data();
            
            $config = array(
                'user_id' => $this->session->userdata('user_id'),
                'file_name' => $data['file_name']
            );
            $this->db->insert('user_images', $config);
            
            $this->load->library('image_lib');                
            createThumbnail($data, "small", 60, 60); 
            createThumbnail($data, "medium", 200, 200);
            return true;
        }
        else
        {
            return false;    
        }
        
    } 


In my models/upload_model.php I have:

PHP Code:

function upload($config)
    {
        if(!file_exists($config['upload_path']))
        {
            mkdir($config['upload_path'], 0777, true);
        }
        
        if($this->upload->do_upload())
        {
            return true;
        }
        else
        {
            return false;
        }    
    }