diff --git a/ANNOUNCE b/ANNOUNCE
index b551f0d..cffc6c0 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.4.0beta73 - August 1, 2009
+Libpng 1.4.0beta74 - August 8, 2009
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -9,29 +9,29 @@
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.4.0beta73.txz (LZMA-compressed, recommended)
-   1.4.0beta73.tar.gz
-   1.4.0beta73.tar.bz2
+   1.4.0beta74.tar.xz (LZMA-compressed, recommended)
+   1.4.0beta74.tar.gz
+   1.4.0beta74.tar.bz2
 
 Source files with LF line endings (for Unix/Linux) without the
 "configure" script
 
-   1.4.0beta73-no-config.txz (LZMA-compressed, recommended)
-   1.4.0beta73-no-config.tar.gz
-   1.4.0beta73-no-config.tar.bz2
+   1.4.0beta74-no-config.tar.xz (LZMA-compressed, recommended)
+   1.4.0beta74-no-config.tar.gz
+   1.4.0beta74-no-config.tar.bz2
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp140b73.zip
-   lp140b73.tar.bz2
+   lp140b74.zip
+   lp140b74.tar.bz2
 
 Other information:
 
-   1.4.0beta73-README.txt
-   1.4.0beta73-KNOWNBUGS.txt
-   1.4.0beta73-LICENSE.txt
-   1.4.0beta73-Y2K-compliance.txt
+   1.4.0beta74-README.txt
+   1.4.0beta74-KNOWNBUGS.txt
+   1.4.0beta74-LICENSE.txt
+   1.4.0beta74-Y2K-compliance.txt
 
 Changes since the last public release (1.2.10):
 
@@ -520,6 +520,15 @@
   Added a prototype for png_64bit_product() in png.c
 
 version 1.4.0beta72 [August 1, 2009]
+  Replaced *.tar.lzma with *.tar.xz in distribution.  Get the xz codec
+    from <http://tukaani.org/xz>.
+
+version 1.4.0beta73 [August 1, 2009]
+  Reject attempt to write iCCP chunk with negative embedded profile length
+    (JD Chen)
+
+version 1.4.0beta74 [August 8, 2009]
+  Changed "trans" to "trans_alpha".
 
 version 1.4.0betaN [future]
   Build shared libraries with -lz and sometimes -lm.
diff --git a/CHANGES b/CHANGES
index 836e746..d136cfe 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2197,13 +2197,16 @@
   Rebuilt configure scripts with autoconf-2.64.
 
 version 1.4.0beta72 [August 1, 2009]
-  Replaced *.tar.lzma with *.txz in distribution.  Get the xz codec
+  Replaced *.tar.lzma with *.tar.xz in distribution.  Get the xz codec
     from <http://tukaani.org/xz>.
 
 version 1.4.0beta73 [August 1, 2009]
   Reject attempt to write iCCP chunk with negative embedded profile length
     (JD Chen)
 
+version 1.4.0beta74 [August 8, 2009]
+  Changed "trans" to "trans_alpha".
+
 version 1.4.0betaN [future]
   Build shared libraries with -lz and sometimes -lm.
 
diff --git a/INSTALL b/INSTALL
index 61826d5..e150a0c 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,5 +1,5 @@
 
-Installing libpng version 1.4.0beta73 - August 1, 2009
+Installing libpng version 1.4.0beta74 - August 8, 2009
 
 On Unix/Linux and similar systems, you can simply type
 
@@ -44,7 +44,7 @@
 correspond to the version of zlib that's installed.
 
 You can rename the directories that you downloaded (they
-might be called "libpng-1.4.0beta73" or "lpng109" and "zlib-1.2.1"
+might be called "libpng-1.4.0beta74" or "lpng109" and "zlib-1.2.1"
 or "zlib121") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
@@ -95,14 +95,14 @@
  CMakeLists.txt    =>  "cmake" script
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       gcc, creates libpng14.so.14.1.4.0beta73)
+                       gcc, creates libpng14.so.14.1.4.0beta74)
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng14.so.14.1.4.0beta73)
+                       (gcc, creates libpng14.so.14.1.4.0beta74)
  makefile.gcmmx    =>  Linux/ELF makefile
-                       (gcc, creates libpng14.so.14.1.4.0beta73,
+                       (gcc, creates libpng14.so.14.1.4.0beta74,
                        uses assembler code tuned for Intel MMX platform)
  makefile.nommx    =>  Linux/ELF makefile
-                       (gcc, creates libpng14.so.14.1.4.0beta73
+                       (gcc, creates libpng14.so.14.1.4.0beta74
                        does not use Intel MMX assembler code)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
@@ -125,12 +125,12 @@
  makefile.openbsd  =>  OpenBSD makefile
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng14.so.14.1.4.0beta73)
+                       creates libpng14.so.14.1.4.0beta74)
  makefile.sunos    =>  Sun makefile
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng14.so.14.1.4.0beta73)
+                       creates libpng14.so.14.1.4.0beta74)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng14.so.14.1.4.0beta73)
+                       creates libpng14.so.14.1.4.0beta74)
  makefile.32sunu   =>  Sun Ultra 32-bit makefile
  makefile.64sunu   =>  Sun Ultra 64-bit makefile
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
diff --git a/KNOWNBUG b/KNOWNBUG
index e4173ea..89b9c3d 100644
--- a/KNOWNBUG
+++ b/KNOWNBUG
@@ -1,5 +1,5 @@
 
-Known bugs in libpng version 1.4.0beta73
+Known bugs in libpng version 1.4.0beta74
 
 1. April 22, 2001: pnggccrd.c has been reported to crash on NetBSD when
    reading interlaced PNG files, when assembler code is enabled but running
diff --git a/LICENSE b/LICENSE
index 3f81564..4394639 100644
--- a/LICENSE
+++ b/LICENSE
@@ -10,7 +10,7 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.4.0beta73, August 1, 2009, are
+libpng versions 1.2.6, August 15, 2004, through 1.4.0beta74, August 8, 2009, are
 Copyright (c) 2004, 2006-2007 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
@@ -108,4 +108,4 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-August 1, 2009
+August 8, 2009
diff --git a/Makefile.am b/Makefile.am
index 82f7056..1565adc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -86,7 +86,7 @@
 	${srcdir}/contrib/pngsuite/* \
 	${srcdir}/contrib/visupng/* \
 	$(TESTS) \
-	example.c libpng-1.4.0beta73.txt pngvcrd.c 
+	example.c libpng-1.4.0beta74.txt pngvcrd.c 
 
 CLEANFILES= pngout.png libpng14.pc libpng14-config libpng.vers \
 libpng.sym
diff --git a/Makefile.in b/Makefile.in
index 2761a63..dd3cc96 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -351,7 +351,7 @@
 	${srcdir}/contrib/pngsuite/* \
 	${srcdir}/contrib/visupng/* \
 	$(TESTS) \
-	example.c libpng-1.4.0beta73.txt pngvcrd.c 
+	example.c libpng-1.4.0beta74.txt pngvcrd.c 
 
 CLEANFILES = pngout.png libpng14.pc libpng14-config libpng.vers \
 libpng.sym
diff --git a/README b/README
index 70bcf0d..585193d 100644
--- a/README
+++ b/README
@@ -1,10 +1,10 @@
-README for libpng version 1.4.0beta73 - August 1, 2009 (shared library 14.0)
+README for libpng version 1.4.0beta74 - August 8, 2009 (shared library 14.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
 
 Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
-libpng-*.txz or libpng-*.tar.bz2 if you want UNIX-style line endings
+libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings
 in the text files, or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
@@ -184,11 +184,11 @@
        descrip.mms      =>  VMS makefile for MMS or MMK
        makefile.std     =>  Generic UNIX makefile (cc, creates static libpng.a)
        makefile.elf     =>  Linux/ELF makefile symbol versioning,
-                            gcc, creates libpng14.so.14.1.4.0beta73)
+                            gcc, creates libpng14.so.14.1.4.0beta74)
        makefile.linux   =>  Linux/ELF makefile
-                            (gcc, creates libpng14.so.14.1.4.0beta73)
+                            (gcc, creates libpng14.so.14.1.4.0beta74)
        makefile.gcmmx   =>  Linux/ELF makefile
-                            (gcc, creates libpng14.so.14.1.4.0beta73,
+                            (gcc, creates libpng14.so.14.1.4.0beta74,
                             uses assembler code tuned for Intel MMX platform)
        makefile.gcc     =>  Generic makefile (gcc, creates static libpng.a)
        makefile.knr     =>  Archaic UNIX Makefile that converts files with
@@ -210,12 +210,12 @@
        makefile.openbsd =>  OpenBSD makefile
        makefile.sgi     =>  Silicon Graphics IRIX (cc, creates static lib)
        makefile.sggcc   =>  Silicon Graphics
-                            (gcc, creates libpng14.so.14.1.4.0beta73)
+                            (gcc, creates libpng14.so.14.1.4.0beta74)
        makefile.sunos   =>  Sun makefile
        makefile.solaris =>  Solaris 2.X makefile
-                            (gcc, creates libpng14.so.14.1.4.0beta73)
+                            (gcc, creates libpng14.so.14.1.4.0beta74)
        makefile.so9     =>  Solaris 9 makefile
-                            (gcc, creates libpng14.so.14.1.4.0beta73)
+                            (gcc, creates libpng14.so.14.1.4.0beta74)
        makefile.32sunu  =>  Sun Ultra 32-bit makefile
        makefile.64sunu  =>  Sun Ultra 64-bit makefile
        makefile.sco     =>  For SCO OSr5  ELF and Unixware 7 with Native cc
diff --git a/configure b/configure
index 9ecbbde..b3e53ac 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.64 for libpng 1.4.0beta73.
+# Generated by GNU Autoconf 2.64 for libpng 1.4.0beta74.
 #
 # Report bugs to <png-mng-implement@lists.sourceforge.net>.
 #
@@ -698,8 +698,8 @@
 # Identity of this package.
 PACKAGE_NAME='libpng'
 PACKAGE_TARNAME='libpng'
-PACKAGE_VERSION='1.4.0beta73'
-PACKAGE_STRING='libpng 1.4.0beta73'
+PACKAGE_VERSION='1.4.0beta74'
+PACKAGE_STRING='libpng 1.4.0beta74'
 PACKAGE_BUGREPORT='png-mng-implement@lists.sourceforge.net'
 PACKAGE_URL=''
 
@@ -1431,7 +1431,7 @@
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures libpng 1.4.0beta73 to adapt to many kinds of systems.
+\`configure' configures libpng 1.4.0beta74 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1501,7 +1501,7 @@
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of libpng 1.4.0beta73:";;
+     short | recursive ) echo "Configuration of libpng 1.4.0beta74:";;
    esac
   cat <<\_ACEOF
 
@@ -1608,7 +1608,7 @@
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-libpng configure 1.4.0beta73
+libpng configure 1.4.0beta74
 generated by GNU Autoconf 2.64
 
 Copyright (C) 2009 Free Software Foundation, Inc.
@@ -2033,7 +2033,7 @@
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by libpng $as_me 1.4.0beta73, which was
+It was created by libpng $as_me 1.4.0beta74, which was
 generated by GNU Autoconf 2.64.  Invocation command line was
 
   $ $0 $@
@@ -2841,7 +2841,7 @@
 
 # Define the identity of the package.
  PACKAGE='libpng'
- VERSION='1.4.0beta73'
+ VERSION='1.4.0beta74'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -2905,7 +2905,7 @@
 
 
 
-PNGLIB_VERSION=1.4.0beta73
+PNGLIB_VERSION=1.4.0beta74
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=4
 PNGLIB_RELEASE=0
@@ -12022,7 +12022,7 @@
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by libpng $as_me 1.4.0beta73, which was
+This file was extended by libpng $as_me 1.4.0beta74, which was
 generated by GNU Autoconf 2.64.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -12086,7 +12086,7 @@
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_version="\\
-libpng config.status 1.4.0beta73
+libpng config.status 1.4.0beta74
 configured by $0, generated by GNU Autoconf 2.64,
   with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"
 
diff --git a/configure.ac b/configure.ac
index 9e22d21..382df2e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,12 +18,12 @@
 
 dnl Version number stuff here:
 
-AC_INIT([libpng], [1.4.0beta73], [png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng], [1.4.0beta74], [png-mng-implement@lists.sourceforge.net])
 AM_INIT_AUTOMAKE
 dnl stop configure from automagically running automake
 AM_MAINTAINER_MODE
 
-PNGLIB_VERSION=1.4.0beta73
+PNGLIB_VERSION=1.4.0beta74
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=4
 PNGLIB_RELEASE=0
diff --git a/example.c b/example.c
index e7e956f..899275f 100644
--- a/example.c
+++ b/example.c
@@ -2,7 +2,7 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * This file has been placed in the public domain by the authors.
  * Maintained 1998-2009 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
diff --git a/libpng-1.4.0beta73.txt b/libpng-1.4.0beta74.txt
similarity index 98%
rename from libpng-1.4.0beta73.txt
rename to libpng-1.4.0beta74.txt
index 0eb8245..79a8878 100644
--- a/libpng-1.4.0beta73.txt
+++ b/libpng-1.4.0beta74.txt
@@ -1,6 +1,6 @@
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.4.0beta73 - August 1, 2009
+ libpng version 1.4.0beta74 - August 8, 2009
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2009 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.4.0beta73 - August 1, 2009
+ libpng versions 0.97, January 1998, through 1.4.0beta74 - August 8, 2009
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2009 Glenn Randers-Pehrson
 
@@ -640,10 +640,10 @@
                      whichever are appropriate for the
                      given color type (png_color_16)
 
-    png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans,
-                     &trans_color);
-    trans          - array of transparent entries for
-                     palette (PNG_INFO_tRNS)
+    png_get_tRNS(png_ptr, info_ptr, &trans_alpha,
+                     &num_trans, &trans_color);
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
     trans_color    - graylevel or color sample values of
                      the single transparent color for
                      non-paletted images (PNG_INFO_tRNS)
@@ -865,7 +865,7 @@
 As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
 added.  It expands the sample depth without changing tRNS to alpha.
 
-As of libpng version 1.4.0beta73, not all possible expansions are supported.
+As of libpng version 1.4.0beta74, not all possible expansions are supported.
 
 In the following table, the 01 means grayscale with depth<8, 31 means
 indexed with depth<8, other numerals represent the color type, "T" means
@@ -1882,10 +1882,11 @@
                      appropriate for the given color type
                      (png_color_16)
 
-    png_set_tRNS(png_ptr, info_ptr, trans, num_trans,
-       trans_color);
-    trans          - array of transparent entries for
-                     palette (PNG_INFO_tRNS)
+    png_set_tRNS(png_ptr, info_ptr, trans_alpha,
+       num_trans, trans_color);
+    trans          - array of transparent entries
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
     trans_color    - graylevel or color sample values
                      (in order red, green, blue) of the
                      single transparent color for
@@ -3035,6 +3036,9 @@
 We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
 input transforms.
 
+The png_struct and info_struct members "trans" and "trans_values" were
+changed to "trans_alpha" and "trans_color", respectively.
+
 The call to png_do_chop() in pngrtran.c, which reduces 16-bit input
 files to 8-bit bit depth, was relocated ahead of the building
 of gamma tables.  This allows us to build 8-bit tables instead
@@ -3168,13 +3172,13 @@
 
 XIII. Y2K Compliance in libpng
 
-August 1, 2009
+August 8, 2009
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.4.0beta73 are Y2K compliant.  It is my belief that earlier
+upward through 1.4.0beta74 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has three year fields.  One is a 2-byte unsigned integer that
diff --git a/libpng.3 b/libpng.3
index b629baf..24d54aa 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "August 1, 2009"
+.TH LIBPNG 3 "August 8, 2009"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.4.0beta73
+libpng \- Portable Network Graphics (PNG) Reference Library 1.4.0beta74
 .SH SYNOPSIS
 \fI\fB
 
@@ -809,7 +809,7 @@
 .SH LIBPNG.TXT
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.4.0beta73 - August 1, 2009
+ libpng version 1.4.0beta74 - August 8, 2009
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2009 Glenn Randers-Pehrson
@@ -820,7 +820,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.4.0beta73 - August 1, 2009
+ libpng versions 0.97, January 1998, through 1.4.0beta74 - August 8, 2009
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2009 Glenn Randers-Pehrson
 
@@ -1449,10 +1449,10 @@
                      whichever are appropriate for the
                      given color type (png_color_16)
 
-    png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans,
-                     &trans_color);
-    trans          - array of transparent entries for
-                     palette (PNG_INFO_tRNS)
+    png_get_tRNS(png_ptr, info_ptr, &trans_alpha,
+                     &num_trans, &trans_color);
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
     trans_color    - graylevel or color sample values of
                      the single transparent color for
                      non-paletted images (PNG_INFO_tRNS)
@@ -1674,7 +1674,7 @@
 As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
 added.  It expands the sample depth without changing tRNS to alpha.
 
-As of libpng version 1.4.0beta73, not all possible expansions are supported.
+As of libpng version 1.4.0beta74, not all possible expansions are supported.
 
 In the following table, the 01 means grayscale with depth<8, 31 means
 indexed with depth<8, other numerals represent the color type, "T" means
@@ -2691,10 +2691,11 @@
                      appropriate for the given color type
                      (png_color_16)
 
-    png_set_tRNS(png_ptr, info_ptr, trans, num_trans,
-       trans_color);
-    trans          - array of transparent entries for
-                     palette (PNG_INFO_tRNS)
+    png_set_tRNS(png_ptr, info_ptr, trans_alpha,
+       num_trans, trans_color);
+    trans          - array of transparent entries
+    trans_alpha    - array of alpha (transparency)
+                     entries for palette (PNG_INFO_tRNS)
     trans_color    - graylevel or color sample values
                      (in order red, green, blue) of the
                      single transparent color for
@@ -3844,6 +3845,9 @@
 We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
 input transforms.
 
+The png_struct and info_struct members "trans" and "trans_values" were
+changed to "trans_alpha" and "trans_color", respectively.
+
 The call to png_do_chop() in pngrtran.c, which reduces 16-bit input
 files to 8-bit bit depth, was relocated ahead of the building
 of gamma tables.  This allows us to build 8-bit tables instead
@@ -3977,13 +3981,13 @@
 
 .SH XIII. Y2K Compliance in libpng
 
-August 1, 2009
+August 8, 2009
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.4.0beta73 are Y2K compliant.  It is my belief that earlier
+upward through 1.4.0beta74 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has three year fields.  One is a 2-byte unsigned integer that
@@ -4207,7 +4211,7 @@
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.4.0beta73 - August 1, 2009:
+Libpng version 1.4.0beta74 - August 8, 2009:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -4230,7 +4234,7 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.4.0beta73, August 1, 2009, are
+libpng versions 1.2.6, August 15, 2004, through 1.4.0beta74, August 8, 2009, are
 Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
@@ -4329,7 +4333,7 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-August 1, 2009
+August 8, 2009
 
 .\" end of man page
 
diff --git a/libpngpf.3 b/libpngpf.3
index 3f34cbb..0ba0d16 100644
--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "August 1, 2009"
+.TH LIBPNGPF 3 "August 8, 2009"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.4.0beta73
+libpng \- Portable Network Graphics (PNG) Reference Library 1.4.0beta74
 (private functions)
 .SH SYNOPSIS
 \fB#include <png.h>\fP
diff --git a/png.5 b/png.5
index 96aaa62..8522f04 100644
--- a/png.5
+++ b/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "August 1, 2009"
+.TH PNG 5 "August 8, 2009"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
diff --git a/png.c b/png.c
index 6e87dcc..b4c6020 100644
--- a/png.c
+++ b/png.c
@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -16,7 +16,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_4_0beta73 Your_png_h_is_not_version_1_4_0beta73;
+typedef version_1_4_0beta74 Your_png_h_is_not_version_1_4_0beta74;
 
 /* Version information for C files.  This had better match the version
  * string defined in png.h.  */
@@ -344,8 +344,8 @@
    if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
 #endif
    {
-      png_free(png_ptr, info_ptr->trans);
-      info_ptr->trans = NULL;
+      png_free(png_ptr, info_ptr->trans_alpha);
+      info_ptr->trans_alpha = NULL;
       info_ptr->valid &= ~PNG_INFO_tRNS;
 #ifndef PNG_FREE_ME_SUPPORTED
       png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
@@ -652,13 +652,13 @@
 #else
 #ifdef __STDC__
    return ((png_charp) PNG_STRING_NEWLINE \
-     "libpng version x 1.4.0beta73 - August 1, 2009" PNG_STRING_NEWLINE \
+     "libpng version x 1.4.0beta74 - August 8, 2009" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2009 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE);
 #else
-      return ((png_charp) "libpng version 1.4.0beta73 - August 1, 2009\
+      return ((png_charp) "libpng version 1.4.0beta74 - August 8, 2009\
       Copyright (c) 1998-2009 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
diff --git a/png.h b/png.h
index 9d0c441..07c1533 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.4.0beta73 - August 1, 2009
+ * libpng version 1.4.0beta74 - August 8, 2009
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *  libpng versions 0.97, January 1998, through 1.4.0beta73 - August 1, 2009: Glenn
+ *  libpng versions 0.97, January 1998, through 1.4.0beta74 - August 8, 2009: Glenn
  *  See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -161,7 +161,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.4.0beta73, August 1, 2009, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.4.0beta74, August 8, 2009, are
  * Copyright (c) 2004, 2006-2007 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -279,7 +279,7 @@
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.4.0beta73 are Y2K compliant.  It is my belief that earlier
+ *    upward through 1.4.0beta74 are Y2K compliant.  It is my belief that earlier
  *    versions were also Y2K compliant.
  *
  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
@@ -335,9 +335,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.4.0beta73"
+#define PNG_LIBPNG_VER_STRING "1.4.0beta74"
 #define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.4.0beta73 - August 1, 2009\n"
+   " libpng version 1.4.0beta74 - August 8, 2009\n"
 
 #define PNG_LIBPNG_VER_SONUM   14
 #define PNG_LIBPNG_VER_DLLNUM  14
@@ -350,7 +350,7 @@
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  73
+#define PNG_LIBPNG_VER_BUILD  74
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -729,7 +729,7 @@
     * single color specified that should be treated as fully transparent.
     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
     */
-   png_bytep trans; /* transparent values for paletted image */
+   png_bytep trans_alpha;    /* alpha values for paletted image */
    png_color_16 trans_color; /* transparent color for non-palette image */
 #endif
 
@@ -1194,7 +1194,7 @@
 
 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   png_bytep trans;           /* transparency values for paletted files */
+   png_bytep trans_alpha;           /* alpha values for paletted files */
    png_color_16 trans_color;  /* transparent color for non-paletted files */
 #endif
 
@@ -1361,7 +1361,7 @@
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef png_structp version_1_4_0beta73;
+typedef png_structp version_1_4_0beta74;
 
 typedef png_struct FAR * FAR * png_structpp;
 
diff --git a/pngconf.h b/pngconf.h
index 1f156cd..5082782 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.4.0beta73 - August 1, 2009
+ * libpng version 1.4.0beta74 - August 8, 2009
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/pngerror.c b/pngerror.c
index 7d462a3..7ae719f 100644
--- a/pngerror.c
+++ b/pngerror.c
@@ -1,7 +1,7 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngget.c b/pngget.c
index f01c5ca..41a56ab 100644
--- a/pngget.c
+++ b/pngget.c
@@ -1,7 +1,7 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -801,7 +801,7 @@
 #if defined(PNG_tRNS_SUPPORTED)
 png_uint_32 PNGAPI
 png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
-   png_bytep *trans, int *num_trans, png_color_16p *trans_color)
+   png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
 {
    png_uint_32 retval = 0;
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
@@ -809,9 +809,9 @@
       png_debug1(1, "in %s retrieval function", "tRNS");
       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       {
-          if (trans != NULL)
+          if (trans_alpha != NULL)
           {
-             *trans = info_ptr->trans;
+             *trans_alpha = info_ptr->trans_alpha;
              retval |= PNG_INFO_tRNS;
           }
 
@@ -826,8 +826,8 @@
              retval |= PNG_INFO_tRNS;
           }
 
-          if (trans != NULL)
-             *trans = NULL;
+          if (trans_alpha != NULL)
+             *trans_alpha = NULL;
       }
       if (num_trans != NULL)
       {
diff --git a/pngmem.c b/pngmem.c
index c5fab95..2c38972 100644
--- a/pngmem.c
+++ b/pngmem.c
@@ -1,7 +1,7 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngpread.c b/pngpread.c
index 2d4af3f..250071e 100644
--- a/pngpread.c
+++ b/pngpread.c
@@ -1,7 +1,7 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngpriv.h b/pngpriv.h
index 5389dd7..40fb675 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -1,7 +1,7 @@
 
 /* pngpriv.h - private declarations for use inside libpng
  *
- * libpng version 1.4.0beta73 - August 1, 2009
+ * libpng version 1.4.0beta74 - August 8, 2009
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/pngread.c b/pngread.c
index 4ea731c..93dacc8 100644
--- a/pngread.c
+++ b/pngread.c
@@ -1,7 +1,7 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1078,11 +1078,11 @@
     defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
 #ifdef PNG_FREE_ME_SUPPORTED
    if (png_ptr->free_me & PNG_FREE_TRNS)
-      png_free(png_ptr, png_ptr->trans);
+      png_free(png_ptr, png_ptr->trans_alpha);
    png_ptr->free_me &= ~PNG_FREE_TRNS;
 #else
    if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
-      png_free(png_ptr, png_ptr->trans);
+      png_free(png_ptr, png_ptr->trans_alpha);
    png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
 #endif
 #endif
diff --git a/pngrio.c b/pngrio.c
index b3fc390..0ab81a5 100644
--- a/pngrio.c
+++ b/pngrio.c
@@ -1,7 +1,7 @@
 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngrtran.c b/pngrtran.c
index 29d6159..7fd083d 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -859,7 +859,7 @@
               int i, istop;
               istop=(int)png_ptr->num_trans;
               for (i=0; i<istop; i++)
-                 png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
+                 png_ptr->trans_alpha[i] = (png_byte)(255 - png_ptr->trans_alpha[i]);
            }
         }
 #endif
@@ -881,7 +881,7 @@
     k=0;
     for (i=0; i<png_ptr->num_trans; i++)
     {
-      if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
+      if (png_ptr->trans_alpha[i] != 0 && png_ptr->trans_alpha[i] != 0xff)
         k=1; /* Partial transparency is present */
     }
     if (k == 0)
@@ -963,26 +963,26 @@
             }
             for (i = 0; i < num_palette; i++)
             {
-               if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
+               if (i < (int)png_ptr->num_trans && png_ptr->trans_alpha[i] != 0xff)
                {
-                  if (png_ptr->trans[i] == 0)
+                  if (png_ptr->trans_alpha[i] == 0)
                   {
                      palette[i] = back;
                   }
-                  else /* if (png_ptr->trans[i] != 0xff) */
+                  else /* if (png_ptr->trans_alpha[i] != 0xff) */
                   {
                      png_byte v, w;
 
                      v = png_ptr->gamma_to_1[palette[i].red];
-                     png_composite(w, v, png_ptr->trans[i], back_1.red);
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
                      palette[i].red = png_ptr->gamma_from_1[w];
 
                      v = png_ptr->gamma_to_1[palette[i].green];
-                     png_composite(w, v, png_ptr->trans[i], back_1.green);
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
                      palette[i].green = png_ptr->gamma_from_1[w];
 
                      v = png_ptr->gamma_to_1[palette[i].blue];
-                     png_composite(w, v, png_ptr->trans[i], back_1.blue);
+                     png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
                      palette[i].blue = png_ptr->gamma_from_1[w];
                   }
                }
@@ -1102,19 +1102,19 @@
 
       for (i = 0; i < istop; i++)
       {
-         if (png_ptr->trans[i] == 0)
+         if (png_ptr->trans_alpha[i] == 0)
          {
             palette[i] = back;
          }
-         else if (png_ptr->trans[i] != 0xff)
+         else if (png_ptr->trans_alpha[i] != 0xff)
          {
             /* The png_composite() macro is defined in png.h */
             png_composite(palette[i].red, palette[i].red,
-               png_ptr->trans[i], back.red);
+               png_ptr->trans_alpha[i], back.red);
             png_composite(palette[i].green, palette[i].green,
-               png_ptr->trans[i], back.green);
+               png_ptr->trans_alpha[i], back.green);
             png_composite(palette[i].blue, palette[i].blue,
-               png_ptr->trans[i], back.blue);
+               png_ptr->trans_alpha[i], back.blue);
          }
       }
 
@@ -1334,7 +1334,7 @@
       if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
       {
          png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
-            png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
+            png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
       }
       else
       {
@@ -3506,7 +3506,7 @@
  */
 void /* PRIVATE */
 png_do_expand_palette(png_row_infop row_info, png_bytep row,
-   png_colorp palette, png_bytep trans, int num_trans)
+   png_colorp palette, png_bytep trans_alpha, int num_trans)
 {
    int shift, value;
    png_bytep sp, dp;
@@ -3597,7 +3597,7 @@
       {
          case 8:
          {
-            if (trans != NULL)
+            if (trans_alpha != NULL)
             {
                sp = row + (png_size_t)row_width - 1;
                dp = row + (png_size_t)(row_width << 2) - 1;
@@ -3607,7 +3607,7 @@
                   if ((int)(*sp) >= num_trans)
                      *dp-- = 0xff;
                   else
-                     *dp-- = trans[*sp];
+                     *dp-- = trans_alpha[*sp];
                   *dp-- = palette[*sp].blue;
                   *dp-- = palette[*sp].green;
                   *dp-- = palette[*sp].red;
diff --git a/pngrutil.c b/pngrutil.c
index ea94248..5df931f 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngset.c b/pngset.c
index aa9913b..ec31c44 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -886,16 +886,16 @@
 #if defined(PNG_tRNS_SUPPORTED)
 void PNGAPI
 png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
-   png_bytep trans, int num_trans, png_color_16p trans_color)
+   png_bytep trans_alpha, int num_trans, png_color_16p trans_color)
 {
    png_debug1(1, "in %s storage function", "tRNS");
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   if (trans != NULL)
+   if (trans_alpha != NULL)
    {
        /*
-        * It may not actually be necessary to set png_ptr->trans here;
+        * It may not actually be necessary to set png_ptr->trans_alpha here;
         * we do it for backward compatibility with the way the png_handle_tRNS
         * function used to do the allocation.
         */
@@ -905,10 +905,10 @@
 #endif
 
        /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
-       png_ptr->trans = info_ptr->trans = (png_bytep)png_malloc(png_ptr,
+       png_ptr->trans_alpha = info_ptr->trans_alpha = (png_bytep)png_malloc(png_ptr,
            (png_size_t)PNG_MAX_PALETTE_LENGTH);
        if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
-          png_memcpy(info_ptr->trans, trans, (png_size_t)num_trans);
+          png_memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans);
    }
 
    if (trans_color != NULL)
diff --git a/pngtest.c b/pngtest.c
index b4ff31a..53a683e 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1045,11 +1045,11 @@
 #endif
 #if defined(PNG_tRNS_SUPPORTED)
    {
-      png_bytep trans;
+      png_bytep trans_alpha;
       int num_trans;
       png_color_16p trans_color;
 
-      if (png_get_tRNS(read_ptr, read_info_ptr, &trans, &num_trans,
+      if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans,
          &trans_color))
       {
          int sample_max = (1 << read_info_ptr->bit_depth);
@@ -1060,7 +1060,7 @@
              ((int)trans_color->red > sample_max ||
              (int)trans_color->green > sample_max ||
              (int)trans_color->blue > sample_max))))
-            png_set_tRNS(write_ptr, write_info_ptr, trans, num_trans,
+            png_set_tRNS(write_ptr, write_info_ptr, trans_alpha, num_trans,
                trans_color);
       }
    }
@@ -1619,4 +1619,4 @@
 }
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_4_0beta73 your_png_h_is_not_version_1_4_0beta73;
+typedef version_1_4_0beta74 your_png_h_is_not_version_1_4_0beta74;
diff --git a/pngtrans.c b/pngtrans.c
index 716d9a6..182b477 100644
--- a/pngtrans.c
+++ b/pngtrans.c
@@ -1,7 +1,7 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngwio.c b/pngwio.c
index 3299743..e7d396b 100644
--- a/pngwio.c
+++ b/pngwio.c
@@ -1,7 +1,7 @@
 
 /* pngwio.c - functions for data output
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngwrite.c b/pngwrite.c
index fe7a314..9e03c98 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -157,10 +157,10 @@
       {
          int j;
          for (j=0; j<(int)info_ptr->num_trans; j++)
-            info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
+            info_ptr->trans_alpha[j] = (png_byte)(255 - info_ptr->trans_alpha[j]);
       }
 #endif
-      png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_color),
+      png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
          info_ptr->num_trans, info_ptr->color_type);
    }
 #endif
diff --git a/pngwtran.c b/pngwtran.c
index 3df724a..fbcdbe7 100644
--- a/pngwtran.c
+++ b/pngwtran.c
@@ -1,7 +1,7 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/pngwutil.c b/pngwutil.c
index c8fb530..9c92e33 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -1,7 +1,7 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.4.0 [August 1, 2009]
+ * Last changed in libpng 1.4.0 [August 8, 2009]
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1082,7 +1082,7 @@
 #if defined(PNG_WRITE_tRNS_SUPPORTED)
 /* Write the tRNS chunk */
 void /* PRIVATE */
-png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
+png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_color_16p tran,
    int num_trans, int color_type)
 {
 #ifdef PNG_USE_LOCAL_ARRAYS
@@ -1099,7 +1099,7 @@
          return;
       }
       /* Write the chunk out as it is */
-      png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans,
+      png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans_alpha,
         (png_size_t)num_trans);
    }
    else if (color_type == PNG_COLOR_TYPE_GRAY)
@@ -1130,7 +1130,7 @@
    }
    else
    {
-      png_warning(png_ptr, "Can't write tRNS with an alpha channel");
+      png_warning(png_ptr, "Can't write tRNS in a PNG with an alpha channel");
    }
 }
 #endif
diff --git a/projects/xcode/libpng.xcodeproj/project.pbxproj b/projects/xcode/libpng.xcodeproj/project.pbxproj
index 550328f..a2d60ad 100644
--- a/projects/xcode/libpng.xcodeproj/project.pbxproj
+++ b/projects/xcode/libpng.xcodeproj/project.pbxproj
@@ -222,7 +222,7 @@
 				COPY_PHASE_STRIP = NO;
 				DYLIB_COMPATIBILITY_VERSION = 14;
 				DYLIB_CURRENT_VERSION = 14;
-				FRAMEWORK_VERSION = 1.4.0beta73;
+				FRAMEWORK_VERSION = 1.4.0beta74;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_ENABLE_FIX_AND_CONTINUE = YES;
 				GCC_OPTIMIZATION_LEVEL = 0;
@@ -248,7 +248,7 @@
 				);
 				DYLIB_COMPATIBILITY_VERSION = 14;
 				DYLIB_CURRENT_VERSION = 14;
-				FRAMEWORK_VERSION = 1.4.0beta73;
+				FRAMEWORK_VERSION = 1.4.0beta74;
 				GCC_GENERATE_DEBUGGING_SYMBOLS = NO;
 				GCC_PRECOMPILE_PREFIX_HEADER = NO;
 				GCC_PREFIX_HEADER = "";
diff --git a/scripts/CMakeLists.txt b/scripts/CMakeLists.txt
index e40c95e..3ac7ad0 100644
--- a/scripts/CMakeLists.txt
+++ b/scripts/CMakeLists.txt
@@ -170,7 +170,7 @@
 
 # SET UP LINKS
 set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#    VERSION 14.${PNGLIB_RELEASE}.1.4.0beta73
+#    VERSION 14.${PNGLIB_RELEASE}.1.4.0beta74
      VERSION 14.${PNGLIB_RELEASE}.0
      SOVERSION 14
      CLEAN_DIRECT_OUTPUT 1)
diff --git a/scripts/libpng-config-head.in b/scripts/libpng-config-head.in
index 976e48a..2d9559e 100755
--- a/scripts/libpng-config-head.in
+++ b/scripts/libpng-config-head.in
@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.4.0beta73
+version=1.4.0beta74
 prefix=""
 libdir=""
 libs=""
diff --git a/scripts/libpng.pc.in b/scripts/libpng.pc.in
index eb32b73..796b32d 100644
--- a/scripts/libpng.pc.in
+++ b/scripts/libpng.pc.in
@@ -5,6 +5,6 @@
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.4.0beta73
+Version: 1.4.0beta74
 Libs: -L${libdir} -lpng14
 Cflags: -I${includedir}
diff --git a/scripts/makefile.32sunu b/scripts/makefile.32sunu
index a16fc95..d19f305 100644
--- a/scripts/makefile.32sunu
+++ b/scripts/makefile.32sunu
@@ -11,7 +11,7 @@
 # Library name:
 LIBNAME=libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.64sunu b/scripts/makefile.64sunu
index e5869df..f1357de 100644
--- a/scripts/makefile.64sunu
+++ b/scripts/makefile.64sunu
@@ -11,7 +11,7 @@
 # Library name:
 LIBNAME=libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.aix b/scripts/makefile.aix
index da9f3cb..80f9c9f 100644
--- a/scripts/makefile.aix
+++ b/scripts/makefile.aix
@@ -23,7 +23,7 @@
 
 LIBNAME=libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 prefix=/usr/local
diff --git a/scripts/makefile.beos b/scripts/makefile.beos
index 0eba86e..2d022f2 100644
--- a/scripts/makefile.beos
+++ b/scripts/makefile.beos
@@ -11,7 +11,7 @@
 # Library name:
 LIBNAME=libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.cygwin b/scripts/makefile.cygwin
index 65705c2..e2c7df0 100644
--- a/scripts/makefile.cygwin
+++ b/scripts/makefile.cygwin
@@ -68,7 +68,7 @@
 LIBNAME = libpng14
 PNGMAJ = 14
 CYGDLL = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 SHAREDLIB=cygpng$(CYGDLL).dll
diff --git a/scripts/makefile.darwin b/scripts/makefile.darwin
index 0fe69dd..05dcd82 100644
--- a/scripts/makefile.darwin
+++ b/scripts/makefile.darwin
@@ -22,7 +22,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.dec b/scripts/makefile.dec
index 6489ac8..887e3c5 100644
--- a/scripts/makefile.dec
+++ b/scripts/makefile.dec
@@ -8,7 +8,7 @@
 
 # Library name:
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 LIBNAME = libpng14
 
diff --git a/scripts/makefile.elf b/scripts/makefile.elf
index 2965ac4..858a041 100644
--- a/scripts/makefile.elf
+++ b/scripts/makefile.elf
@@ -16,7 +16,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.hp64 b/scripts/makefile.hp64
index c412934..b315841 100644
--- a/scripts/makefile.hp64
+++ b/scripts/makefile.hp64
@@ -21,7 +21,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.hpgcc b/scripts/makefile.hpgcc
index 4d59447..10ad4be 100644
--- a/scripts/makefile.hpgcc
+++ b/scripts/makefile.hpgcc
@@ -11,7 +11,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.hpux b/scripts/makefile.hpux
index 2915ad8..6ff0349 100644
--- a/scripts/makefile.hpux
+++ b/scripts/makefile.hpux
@@ -21,7 +21,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.linux b/scripts/makefile.linux
index 88f8b73..cfeae97 100644
--- a/scripts/makefile.linux
+++ b/scripts/makefile.linux
@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.mingw b/scripts/makefile.mingw
index e73f9f1..e51f5bd 100644
--- a/scripts/makefile.mingw
+++ b/scripts/makefile.mingw
@@ -68,7 +68,7 @@
 LIBNAME = libpng14
 PNGMAJ = 14
 MINGDLL = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 SHAREDLIB=libpng$(MINGDLL).dll
diff --git a/scripts/makefile.ne12bsd b/scripts/makefile.ne12bsd
index 8468d7b..329c807 100644
--- a/scripts/makefile.ne12bsd
+++ b/scripts/makefile.ne12bsd
@@ -17,7 +17,7 @@
 
 LIB=	png14
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.4.0beta73
+SHLIB_MINOR=	1.4.0beta74
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
diff --git a/scripts/makefile.netbsd b/scripts/makefile.netbsd
index de94d82..c552c17 100644
--- a/scripts/makefile.netbsd
+++ b/scripts/makefile.netbsd
@@ -17,7 +17,7 @@
 
 LIB=	png
 SHLIB_MAJOR=	3
-SHLIB_MINOR=	1.4.0beta73
+SHLIB_MINOR=	1.4.0beta74
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
diff --git a/scripts/makefile.nommx b/scripts/makefile.nommx
index ac94537..a890ae8 100644
--- a/scripts/makefile.nommx
+++ b/scripts/makefile.nommx
@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.openbsd b/scripts/makefile.openbsd
index bf6a5b1..9a8b6ff 100644
--- a/scripts/makefile.openbsd
+++ b/scripts/makefile.openbsd
@@ -11,7 +11,7 @@
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.4.0beta73
+SHLIB_MINOR=	1.4.0beta74
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
diff --git a/scripts/makefile.sco b/scripts/makefile.sco
index 8a95149..06e8066 100644
--- a/scripts/makefile.sco
+++ b/scripts/makefile.sco
@@ -12,7 +12,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.sggcc b/scripts/makefile.sggcc
index f81aee3..c57652b 100644
--- a/scripts/makefile.sggcc
+++ b/scripts/makefile.sggcc
@@ -9,7 +9,7 @@
 # Library name:
 LIBNAME=libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.sgi b/scripts/makefile.sgi
index 41956bc..9622722 100644
--- a/scripts/makefile.sgi
+++ b/scripts/makefile.sgi
@@ -9,7 +9,7 @@
 # Library name:
 LIBNAME=libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/makefile.so9 b/scripts/makefile.so9
index a5b73f0..c5974cc 100644
--- a/scripts/makefile.so9
+++ b/scripts/makefile.so9
@@ -11,7 +11,7 @@
 
 # Library name:
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 LIBNAME = libpng14
 
diff --git a/scripts/makefile.solaris b/scripts/makefile.solaris
index a81f8d3..917e79a 100644
--- a/scripts/makefile.solaris
+++ b/scripts/makefile.solaris
@@ -11,7 +11,7 @@
 # Library name:
 LIBNAME = libpng14
 PNGMAJ = 14
-PNGMIN = 1.4.0beta73
+PNGMIN = 1.4.0beta74
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # Shared library names:
diff --git a/scripts/pngos2.def b/scripts/pngos2.def
index 362453a..ba02c5a 100644
--- a/scripts/pngos2.def
+++ b/scripts/pngos2.def
@@ -2,7 +2,7 @@
 ; PNG.LIB module definition file for OS/2
 ;----------------------------------------
 
-; Version 1.4.0beta73
+; Version 1.4.0beta74
 
 LIBRARY		PNG
 DESCRIPTION	"PNG image compression library for OS/2"
diff --git a/scripts/pngwin.def b/scripts/pngwin.def
index c209605..4ee6249 100644
--- a/scripts/pngwin.def
+++ b/scripts/pngwin.def
@@ -5,7 +5,7 @@
 LIBRARY
 
 EXPORTS
-;Version 1.4.0beta73
+;Version 1.4.0beta74
   png_build_grayscale_palette
   png_chunk_error
   png_chunk_warning