From 10c933f3b858858e1a34d2ea3e0b642d60e1eae3 Mon Sep 17 00:00:00 2001
From: nicolaasuni <info@tecnick.com>
Date: Mon, 23 Sep 2013 16:26:07 +0100
Subject: [PATCH] 6.0.033 (2013-09-23) - Bug fix related to PNG image
 transparency using GD library.

---
 CHANGELOG.TXT            |  3 +++
 README.TXT               |  2 +-
 composer.json            |  2 +-
 include/tcpdf_static.php |  2 +-
 tcpdf.php                | 24 ++++++++++++------------
 5 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.TXT b/CHANGELOG.TXT
index 9b17617..7d7272c 100644
--- a/CHANGELOG.TXT
+++ b/CHANGELOG.TXT
@@ -1,3 +1,6 @@
+6.0.033 (2013-09-23)
+	- Bug fix related to PNG image transparency using GD library.
+
 6.0.032 (2013-09-23)
 	- Bug #838 "Fatal error when imagick cannot handle the image, even though GD is available and can" was fixed.
 
diff --git a/README.TXT b/README.TXT
index 3c470cb..130a3d8 100644
--- a/README.TXT
+++ b/README.TXT
@@ -8,7 +8,7 @@ http://sourceforge.net/donate/index.php?group_id=128076
 ------------------------------------------------------------
 
 Name: TCPDF
-Version: 6.0.032
+Version: 6.0.033
 Release date: 2013-09-23
 Author:	Nicola Asuni
 
diff --git a/composer.json b/composer.json
index 96ab866..f728b3a 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,6 @@
 {
 	"name": "tecnick.com/tcpdf",
-	"version": "6.0.032",
+	"version": "6.0.033",
 	"homepage": "http://www.tcpdf.org/",
 	"type": "library",
 	"description": "TCPDF is a PHP class for generating PDF documents.",
diff --git a/include/tcpdf_static.php b/include/tcpdf_static.php
index d2067e9..c30b97d 100644
--- a/include/tcpdf_static.php
+++ b/include/tcpdf_static.php
@@ -55,7 +55,7 @@ class TCPDF_STATIC {
 	 * Current TCPDF version.
 	 * @private static
 	 */
-	private static $tcpdf_version = '6.0.032';
+	private static $tcpdf_version = '6.0.033';
 
 	/**
 	 * String alias for total number of pages.
diff --git a/tcpdf.php b/tcpdf.php
index b33a1a1..9461842 100644
--- a/tcpdf.php
+++ b/tcpdf.php
@@ -1,7 +1,7 @@
 <?php
 //============================================================+
 // File name   : tcpdf.php
-// Version     : 6.0.032
+// Version     : 6.0.033
 // Begin       : 2002-08-03
 // Last Update : 2013-09-23
 // Author      : Nicola Asuni - Tecnick.com LTD - www.tecnick.com - info@tecnick.com
@@ -104,7 +104,7 @@
  * Tools to encode your unicode fonts are on fonts/utils directory.</p>
  * @package com.tecnick.tcpdf
  * @author Nicola Asuni
- * @version 6.0.032
+ * @version 6.0.033
  */
 
 // TCPDF configuration
@@ -128,7 +128,7 @@ require_once(dirname(__FILE__).'/include/tcpdf_static.php');
  * TCPDF project (http://www.tcpdf.org) has been originally derived in 2002 from the Public Domain FPDF class by Olivier Plathey (http://www.fpdf.org), but now is almost entirely rewritten.<br>
  * @package com.tecnick.tcpdf
  * @brief PHP class for generating PDF documents without requiring external extensions.
- * @version 6.0.032
+ * @version 6.0.033
  * @author Nicola Asuni - info@tecnick.com
  */
 class TCPDF {
@@ -7216,7 +7216,8 @@ class TCPDF {
 				for ($xpx = 0; $xpx < $wpx; ++$xpx) {
 					for ($ypx = 0; $ypx < $hpx; ++$ypx) {
 						$color = imagecolorat($img, $xpx, $ypx);
-						$alpha = $this->getGDgamma($color); // correct gamma
+						// get and correct gamma color
+						$alpha = $this->getGDgamma($img, $color);
 						imagesetpixel($imgalpha, $xpx, $ypx, $alpha);
 					}
 				}
@@ -7251,26 +7252,25 @@ class TCPDF {
 
 	/**
 	 * Get the GD-corrected PNG gamma value from alpha color
+	 * @param $img (int) GD image Resource ID.
 	 * @param $c (int) alpha color
 	 * @protected
 	 * @since 4.3.007 (2008-12-04)
 	 */
-	protected function getGDgamma($c) {
-		if (!isset($this->gdgammacache["'".$c."'"])) {
-			// shifts off the first 24 bits (where 8x3 are used for each color),
-			// and returns the remaining 7 allocated bits (commonly used for alpha)
-			$alpha = ($c >> 24);
+	protected function getGDgamma($img, $c) {
+		if (!isset($this->gdgammacache['#'.$c])) {
+			$colors = imagecolorsforindex($img, $c);
 			// GD alpha is only 7 bit (0 -> 127)
-			$alpha = (((127 - $alpha) / 127) * 255);
+			$this->gdgammacache['#'.$c] = (((127 - $colors['alpha']) / 127) * 255);
 			// correct gamma
-			$this->gdgammacache["'".$c."'"] = (pow(($alpha / 255), 2.2) * 255);
+			$this->gdgammacache['#'.$c] = (pow(($this->gdgammacache['#'.$c] / 255), 2.2) * 255);
 			// store the latest values on cache to improve performances
 			if (count($this->gdgammacache) > 8) {
 				// remove one element from the cache array
 				array_shift($this->gdgammacache);
 			}
 		}
-		return $this->gdgammacache["'".$c."'"];
+		return $this->gdgammacache['#'.$c];
 	}
 
 	/**