Fix issue #427
diff --git a/system/core/Security.php b/system/core/Security.php
index 4593a10..227217e 100644
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -561,6 +561,19 @@
 	// ----------------------------------------------------------------
 
 	/**
+	 * Strip Image Tags
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	public function strip_image_tags($str)
+	{
+		return preg_replace(array('#<img\s+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img\s+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
+	}
+
+	// ----------------------------------------------------------------
+
+	/**
 	 * Compact Exploded Words
 	 *
 	 * Callback function for xss_clean() to remove whitespace from
diff --git a/system/helpers/security_helper.php b/system/helpers/security_helper.php
index 7968f9e..0e8e9f9 100644
--- a/system/helpers/security_helper.php
+++ b/system/helpers/security_helper.php
@@ -108,7 +108,8 @@
 	 */
 	function strip_image_tags($str)
 	{
-		return preg_replace(array('#<img\s+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img\s+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
+		$CI =& get_instance();
+		return $CI->security->strip_image_tags($str);
 	}
 }
 
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 484e306..0d9c65f 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1360,7 +1360,7 @@
 	 */
 	public function strip_image_tags($str)
 	{
-		return $this->CI->input->strip_image_tags($str);
+		return $this->CI->security->strip_image_tags($str);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 28e2f94..27381b4 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -70,7 +70,8 @@
 	 - ``set_realpath()`` can now also handle file paths as opposed to just directories.
 	 - Added an optional paramater to ``delete_files()`` to enable it to skip deleting files such as .htaccess and index.html.
 	 - ``read_file()`` is now a deprecated alias of ``file_get_contents()``.
-   -  :doc:`Date Helper <helpers/date_helper>` Added optional fourth parameter to ``timezone_menu()`` that allows more attributes to be added to the generated select tag
+   -  Added an optional parameter to :doc:`Date Helper <helpers/date_helper>` function ``timezone_menu()`` that allows more attributes to be added to the generated select tag.
+   -  :doc:`Security Helper <helpers/security_helper>` function ``strip_image_tags()`` is now an alias for the same method in the :doc:`Security Library <libraries/security>`.
 
 -  Database
 
@@ -190,6 +191,7 @@
    -  $config['time_reference'] now supports all timezone strings supported by PHP.
    -  Added support for HTTP code 303 ("See Other") in set_status_header().
    -  Changed :doc:`Config Library <libraries/config>` method site_url() to accept an array as well.
+   -  Added method ``strip_image_tags()`` to the :doc:`Security Library <libraries/security>`.
 
 Bug fixes for 3.0
 ------------------
@@ -294,6 +296,7 @@
 -  Fixed a bug where :doc:`URL Helper <helpers/url_helper>` function anchor_popup() ignored the attributes argument if it is not an array.
 -  Fixed a bug (#1328) - :doc:`Form Validation Library <libraries/form_validation>` didn't properly check the type of the form fields before processing them.
 -  Fixed a bug (#79) - :doc:`Form Validation Library <libraries/form_validation>` didn't properly validate array fields that use associative keys or have custom indexes.
+-  Fixed a bug (#427) - :doc:`Form Validation Library <libraries/form_validation>` method ``strip_image_tags()`` was an alias to a non-existent method.
 
 Version 2.1.1
 =============