Codeigniter allow file types except...

CI: MY_Upload

<?php if( ! defined('BASEPATH') ) exit('No direct script access allowed');

/*
	If we allow all file type, allow for exclusions as well
*/
class MY_Upload Extends CI_Upload{

	public function set_allowed_types($types)
	{
		$this->allowed_types = explode('|', $types);
		if ( count($this->allowed_types) === 1 && in_array('*', $this->allowed_types))
		{
			$this->allowed_types = '*';
			return;
		}
	}

	function is_allowed_filetype($ignore_mime=FALSE){

		$ext = strtolower(ltrim($this->file_ext, '.'));

		if($this->allowed_types === '*'){
			return TRUE;
		}

		if (in_array('*', $this->allowed_types))
		{
			if( in_array($ext, $this->allowed_types)){
				return FALSE;
			}

			// Get the mime types that the file extension should refer to
			$mime = $this->mimes_types($ext);

			// If the extension relates to the mime type, then allow the file
			if (is_array($mime))
			{
				if (in_array($this->file_type, $mime, TRUE))
				{
					return TRUE;
				}
			}
			elseif ($mime == $this->file_type)
			{
					return TRUE;
			}

			return TRUE;
		}

		if (count($this->allowed_types) == 0 OR ! is_array($this->allowed_types))
		{
			$this->set_error('upload_no_file_types');
			return FALSE;
		}



		if ( ! in_array($ext, $this->allowed_types))
		{
			return FALSE;
		}

		// Images get some additional checks
		$image_types = array('gif', 'jpg', 'jpeg', 'png', 'jpe');

		if (in_array($ext, $image_types))
		{
			if (getimagesize($this->file_temp) === FALSE)
			{
				return FALSE;
			}
		}

		if ($ignore_mime === TRUE)
		{
			return TRUE;
		}

		$mime = $this->mimes_types($ext);

		if (is_array($mime))
		{
			if (in_array($this->file_type, $mime, TRUE))
			{
				return TRUE;
			}
		}
		elseif ($mime == $this->file_type)
		{
				return TRUE;
		}

		return FALSE;
	}
}

MY_Upload.php

<?php if( ! defined('BASEPATH') ) exit('No direct script access allowed');

/*
	If we allow all file type, allow for exclusions as well
*/
class MY_Upload Extends CI_Upload{

	public function set_allowed_types($types)
	{
		$this->allowed_types = explode('|', $types);
		if ( count($this->allowed_types) === 1 && in_array('*', $this->allowed_types))
		{
			$this->allowed_types = '*';
			return;
		}
	}

	function is_allowed_filetype($ignore_mime=FALSE){

		$ext = strtolower(ltrim($this->file_ext, '.'));

		if($this->allowed_types === '*'){
			return TRUE;
		}

		if (in_array('*', $this->allowed_types))
		{
			if( in_array($ext, $this->allowed_types)){
				return FALSE;
			}

			// Get the mime types that the file extension should refer to
			$mime = $this->mimes_types($ext);

			// If the extension relates to the mime type, then allow the file
			if (is_array($mime))
			{
				if (in_array($this->file_type, $mime, TRUE))
				{
					return TRUE;
				}
			}
			elseif ($mime == $this->file_type)
			{
					return TRUE;
			}

			return TRUE;
		}

		if (count($this->allowed_types) == 0 OR ! is_array($this->allowed_types))
		{
			$this->set_error('upload_no_file_types');
			return FALSE;
		}



		if ( ! in_array($ext, $this->allowed_types))
		{
			return FALSE;
		}

		// Images get some additional checks
		$image_types = array('gif', 'jpg', 'jpeg', 'png', 'jpe');

		if (in_array($ext, $image_types))
		{
			if (getimagesize($this->file_temp) === FALSE)
			{
				return FALSE;
			}
		}

		if ($ignore_mime === TRUE)
		{
			return TRUE;
		}

		$mime = $this->mimes_types($ext);

		if (is_array($mime))
		{
			if (in_array($this->file_type, $mime, TRUE))
			{
				return TRUE;
			}
		}
		elseif ($mime == $this->file_type)
		{
				return TRUE;
		}

		return FALSE;
	}
}