[pngzop] Minor editing of the license information

and adds "-e extension" and "-d directory" options similar to those in
pngcrush.

README_master.txt

@@ -1,6 +0,0 @@
-
-/*
-  This is the master branch of the "pmt" tree.
-  Individual projects are in separate branches,
-    e.g. pngcrush is in the "pngcrush" branch.
-*/

pngzop

@@ -0,0 +1,167 @@
+#!/bin/sh
+
+# pngzop
+
+# Copyright 2013 by Glenn Randers-Pehrson
+# Released under the pngcrush license (which is equivalent to the zlib
+# license plus UCITA disclaimers).
+
+# Extracts the concatenated data from the IDAT chunks in a set of PNG files,
+# recompresses them with zopfli, and embeds them in a new set of PNG files
+# with suffix ".png" replaced (by default) with "_pngzop.png"
+
+# Requires zopfli, pngcrush (version 1.7.65 or later), zpipe (from the
+# zlib-1.2.7 or later distribution, in the "examples" directory), pngfix
+# (from the libpng-1.6.3 or later distribution), and "mkdir -p",
+# along with these programs that should have been installed along with
+# this "pngzop" script:
+#
+#        pngzop_get_ihdr.exe
+#        pngzop_get_idat.exe
+#        pngzop_get_iend.exe
+#        pngzop_zlib_to_idat.exe
+
+# Usage:
+# pngzop [-b|--blacken] [-d|--directory dir] [-e|--extension ext] *.png
+#        (to overwrite the input, use "-e .png")
+
+# Input: *.png
+# Output: *_pngzop.png
+
+# Get temporary directory; use TMPDIR if defined, otherwise /tmp
+case x${TMPDIR} in
+   x)
+      temp=/tmp/pngzop-$$
+      ;;
+   *)
+      temp=$TMPDIR/pngzop-$$
+      ;;
+esac
+
+mkdir -p $temp
+      
+blacken=
+directory=.
+extension=
+
+for x in $*
+do
+case $1 in
+  -b|--blacken)
+    blacken="-blacken"
+    shift;;
+  -d|--directory)
+    shift
+    directory=$1
+    shift;;
+  -e|--extension)
+    shift
+    extension=$1
+    shift;;
+  *)
+    break;;
+esac
+done
+
+# If a directory was defined, don't change filenames (extension == .png)
+# unless an extension was also defined.
+case x$directory in
+    x.)
+      ;;
+    *)
+      case x$extension in
+        x)
+          extension=.png
+          ;;
+        *)
+          ;;
+      esac
+      mkdir -p $directory
+      ;;
+esac
+
+case x$extension in
+  x)
+    extension=_pngzop.png
+    ;;
+  *)
+    ;;
+esac
+
+for x in $*
+do
+  root=`echo $x | sed -e s/.png$//`
+
+  # prepass to reduce and possibly blacken
+  pngcrush -q -m 1 -force -reduce $blacken $x ${temp}/${root}_temp.png
+
+  pngzop_get_ihdr.exe < ${temp}/${root}_temp.png > ${temp}/${root}_pz.png
+
+  # Generate trial PNGs with filter none, 4 PNG filters, and adaptive
+  # filter
+  for f in 0 1 2 3 4 5
+  do
+    pngcrush -q -m 1 -f $f -force ${temp}/${root}_temp.png \
+              ${temp}/${root}_f$f.png &
+  done
+  wait
+
+  # Extract and decompress the zlib datastream from the concatenated
+  # IDAT chunks.
+  for f in 0 1 2 3 4 5
+  do
+    pngzop_get_idat.exe < ${temp}/${root}_f$f.png | zpipe -d > \
+                          ${temp}/${root}_f$f.idat &
+  done
+  wait
+  rm -f ${temp}/${root}_f?.png
+
+  # Recompress the IDAT data using zopfli
+  for f in 0 1 2 3 4 5
+  do
+    zopfli --i25 --zlib ${temp}/${root}_f$f.idat &
+  done
+  wait
+  rm -f ${temp}/${root}_f?.idat
+
+  # Copy the smallest result to file.zlib
+
+  file=${temp}/${root}_f0.idat.zlib
+  smallest=$file
+  smallsize=`ls -l $file | sed -e "
+s/[^ 	]*[	 ]*\
+[^ 	]*[	 ]*\
+[^ 	]*[	 ]*\
+[^ 	]*[	 ]*\
+//" -e "s/[ 	].*//"`
+
+  for f in 1 2 3 4 5
+  do
+
+  file=${temp}/${root}_f$f.idat.zlib
+
+  size=`ls -l $file | sed -e "
+s/[^ 	]*[	 ]*\
+[^ 	]*[	 ]*\
+[^ 	]*[	 ]*\
+[^ 	]*[	 ]*\
+//" -e "s/[ 	].*//"`
+
+  if [ $smallsize -gt $size 	] ; then
+  smallest=$file
+  smallsize=$size
+  fi
+  done
+
+  pngzop_zlib_to_idat.exe < $smallest >> ${temp}/${root}_pz.png
+  rm -f ${temp}/${root}_f?.idat.zlib
+  pngzop_get_iend.exe < ${temp}/${root}_temp.png >> ${temp}/${root}_pz.png
+  rm ${temp}/${root}_temp.png
+
+  # Optimize the CMF bytes and put the result in desired destination.
+  pngfix -o --quiet --out=${directory}/${root}${extension} \
+         ${temp}/${root}_pz.png
+  rm ${temp}/${root}_pz.png
+
+done
+rm -rf $temp

pngzop-1.0.1-README.txt

@@ -0,0 +1,77 @@
+/*
+  This is the pngzop branch of the "pmt" tree.
+  Code for supporting the "zopfli" compression method
+  in PNG files will appear here.
+
+  Eventually this collection of scripts might be incorporated
+  into pngcrush.
+
+  Copyright 2013 by Glenn Randers-Pehrson
+  Released under the pngcrush license (which is equivalent to the zlib
+  license plus UCITA disclaimers). See DISCLAIMERS and LICENSE below.
+
+  Usage:
+  pngzop [-b|--blacken] [-d|--directory dir] [-e|--extension ext] *.png
+
+  Input: *.png
+  Output (default): *_pngzop.png (to overwrite the input, use "-e .png")
+
+  Pngzop does the following:
+
+    1. Preprocesses the input file(s) with pngcrush -reduce
+       (and optionally -blacken to clean up "dirty" transparent pixels)
+
+    2. Uses pngcrush to write 6 test files, with 5 PNG filters and adaptive
+       filtering.
+
+    3. Extracts the IDAT contents from each of the 6 files.
+
+    4. Recompresses the IDAT contents with zopfli (25 iterations).
+
+    5. Reassembles the PNG file using the smallest of the zopfli-compressed
+       results.
+
+    6. Postprocesses the PNG file with "pngfix" to optimize the windowBits
+       field, to minimize memory use during later decompression.
+
+  Pngzop requires zopfli, pngcrush (version 1.7.65 or later), zpipe (from
+  the "examples" directory of the zlib-1.2.7 or later distribution),
+  pngfix (from the libpng-1.6.3 or later distribution), and "mkdir -p",
+  along with these programs that should have been installed from their "C"
+  sources along with this "pngzop" script:
+ 
+         pngzop_get_ihdr.exe
+         pngzop_get_idat.exe
+         pngzop_get_iend.exe
+         pngzop_zlib_to_idat.exe
+
+  DISCLAIMERS:
+ 
+  The pngzop software is supplied "AS IS".  The Author disclaims all
+  warranties, expressed or implied, including, without limitation, the
+  warranties of merchantability and of fitness for any purpose.  The
+  Author assumes no liability for direct, indirect, incidental, special,
+  exemplary, or consequential damages, which may result from the use of
+  the pngzop software, even if advised of the possibility of such damage.
+  There is no warranty against interference with your enjoyment of the
+  computer software or against infringement.  There is no warranty that
+  the Author's efforts or the computer software will fulfill any of your
+  particular purposes or needs.  This computer software is provided with
+  all faults, and the entire risk of satisfactory quality, performance,
+  accuracy, and effort is with the user.
+ 
+  LICENSE:
+ 
+  Permission is hereby irrevocably granted to everyone to use, copy,
+  modify, and distribute this source code, or portions hereof, or
+  executable programs compiled from it, for any purpose, without payment
+  of any fee, subject to the following restrictions:
+ 
+  1. The origin of this source code must not be misrepresented.
+ 
+  2. Altered versions must be plainly marked as such and must not be
+     misrepresented as being the original source.
+ 
+  3. This Copyright notice, disclaimer, and license may not be removed
+     or altered from any source or altered source distribution.
+*/

pngzop_get_idat.c

@@ -0,0 +1,76 @@
+#include <stdio.h>
+
+/* Copyright 2013 Glenn Randers-Pehrson
+ * Released under the pngcrush license (equivalent to the libpng license)
+ */
+
+/* Usage:            
+ * pngidat.exe < file.png > file.zdat
+ *
+ * file.idat is the zlib datastream from the PNG IDAT chunks.
+ *
+ */
+
+main()
+{
+   unsigned int i;
+   unsigned int buf[5];
+   unsigned int c;
+
+   buf[4]='\0';
+
+/* Skip 8-byte signature */
+   for (i=8; i; i--)
+      c=getchar();
+
+for (;;)
+{
+   /* read length */
+   unsigned int length;
+   buf[0]=getchar();
+   if (buf[0] == EOF)
+      break;
+   buf[1]=getchar();
+   buf[2]=getchar();
+   buf[3]=getchar();
+   length=buf[0]<<24 | buf[1]<<16 | buf[2] << 8 | buf[3];
+   /* read chunkname */
+   buf[0]=getchar();
+   buf[1]=getchar();
+   buf[2]=getchar();
+   buf[3]=getchar();
+   if (buf[0] == 'I' && buf[1] == 'D' && buf[2] == 'A' && buf[3] == 'T')
+   {
+      /* copy the data bytes */
+      for (i=length; i; i--)
+      {
+         c=getchar();
+         if (c == EOF)
+            break;
+         putchar(c);
+      }
+      if (c == EOF)
+         break;
+      /* skip crc bytes */
+      for (i=4; i; i--)
+      {
+         c=getchar();
+      }
+   }
+
+   else if (buf[0] == 'I' && buf[1] == 'E' && buf[2] == 'N' && buf[3] == 'D')
+     break;
+
+   else
+   {
+      for (i=length+4; i; i--)
+      {
+         c=getchar();
+         if (c == EOF)
+            break;
+      }
+      if (c == EOF)
+         break;
+   }
+}
+}

pngzop_get_iend.c

@@ -0,0 +1,112 @@
+
+#include <stdio.h>
+
+/* Copyright 2013 Glenn Randers-Pehrson */
+
+/* Usage:            
+ * pngiend.exe < file.png > file.iend
+ *
+ * file.iend is the image datastream, minus everything through the
+ * last IDAT chunk.
+ */
+
+main()
+{
+   unsigned int c;
+   unsigned int i;
+   unsigned int len[5];
+   unsigned int length;
+   unsigned int mode;
+   unsigned int name[5];
+
+   len[4]='\0';
+   name[4]='\0';
+   mode=0; /* Looking for IDAT */
+
+/* Skip 8-byte signature */
+   for (i=8; i; i--)
+   {
+      c=getchar();
+      if (c == EOF)
+         break;
+   }
+
+   for (;;)
+   {
+      /* read length */
+      len[0]=getchar();
+      if (len[0] == EOF)
+         break;
+      len[1]=getchar();
+      len[2]=getchar();
+      len[3]=getchar();
+      if (len[3] == EOF)
+         break;
+      length=len[0]<<24 | len[1]<<16 | len[2]<< 8 | len[3];
+
+      /* read chunkname */
+      name[0]=getchar();
+      name[1]=getchar();
+      name[2]=getchar();
+      name[3]=getchar();
+      if (name[3] == EOF)
+         break;
+
+      if (name[0] == 'I' && name[1] == 'D' && name[2] == 'A' && \
+          name[3] == 'T')
+         {
+            if (mode == 0)
+               mode = 1; /* found IDAT */
+         }
+      else
+         {
+            if (mode == 1)
+               mode = 2; /* found chunk after IDAT */
+         }
+   
+      if (mode == 2)
+         {
+            /* copy the length bytes */
+            putchar(len[0]);
+            putchar(len[1]);
+            putchar(len[2]);
+            putchar(len[3]);
+             
+            /* copy the name bytes */
+            putchar(name[0]);
+            putchar(name[1]);
+            putchar(name[2]);
+            putchar(name[3]);
+         }
+         
+      /* skip or copy the data bytes */
+      for (i=length; i; i--)
+      {
+         c=getchar();
+         if (c == EOF)
+            break;
+         if (mode == 2)
+            putchar(c);
+      }
+      if (c == EOF)
+         break;
+
+      /* skip or copy crc bytes */
+      for (i=4; i; i--)
+      {
+         c=getchar();
+         if (c == EOF)
+            break;
+         if (mode == 2)
+            putchar(c);
+      }
+      if (c == EOF)
+         break;
+   
+      if (name[0] == 'I' && name[1] == 'E' && name[2] == 'N' && \
+          name[3] == 'D')
+         {
+            break;
+         }
+   }
+}

pngzop_get_ihdr.c

@@ -0,0 +1,98 @@
+
+#include <stdio.h>
+
+/* Copyright 2013 Glenn Randers-Pehrson */
+
+/* Usage:            
+ * pngidat.exe < file.png > file.ihdr
+ *
+ * file.ihdr is the image datastream, with the PNG signature bytes
+ * and all chunks up to the first IDAT.
+ */
+
+main()
+{
+   unsigned int i;
+   unsigned int len[5];
+   unsigned int name[5];
+   unsigned int c;
+
+   len[4]='\0';
+   name[4]='\0';
+
+/* Copy 8-byte signature */
+   for (i=8; i; i--)
+   {
+      c=getchar();
+      if (c == EOF)
+         break;
+      putchar(c);
+   }
+
+   for (;;)
+   {
+      /* read length */
+      unsigned int length;
+      len[0]=getchar();
+      if (len[0] == EOF)
+         break;
+      len[1]=getchar();
+      len[2]=getchar();
+      len[3]=getchar();
+      if (len[3] == EOF)
+         break;
+      length=len[0]<<24 | len[1]<<16 | len[2] << 8 | len[3];
+
+      /* read chunkname */
+      name[0]=getchar();
+      name[1]=getchar();
+      name[2]=getchar();
+      name[3]=getchar();
+      if (name[3] == EOF)
+         break;
+
+      if (name[0] == 'I' && name[1] == 'D' && name[2] == 'A' && name[3] == 'T')
+          break;
+   
+      /* copy the length bytes */
+      putchar(len[0]);
+      putchar(len[1]);
+      putchar(len[2]);
+      putchar(len[3]);
+       
+      /* copy the name bytes */
+      putchar(name[0]);
+      putchar(name[1]);
+      putchar(name[2]);
+      putchar(name[3]);
+   
+      /* copy the data bytes */
+      for (i=length; i; i--)
+      {
+         c=getchar();
+         if (c == EOF)
+            break;
+         putchar(c);
+      }
+      if (c == EOF)
+         break;
+
+      /* copy crc bytes */
+      for (i=4; i; i--)
+      {
+         c=getchar();
+         if (c == EOF)
+            break;
+         putchar(c);
+      }
+      if (c == EOF)
+         break;
+   
+      if (name[0] == 'I' && name[1] == 'E' && name[2] == 'N' && name[3] == 'D')
+      {
+         /* should not happen */
+         break;
+      }
+   
+   }
+}

pngzop_references.html

@@ -0,0 +1,15 @@
+<html><head><title>Zopli references</title></head>
+<body>
+<h2>Zopfli references</h2>
+<ul>
+<li>
+<a href="https://code.google.com/p/zopfli/downloads/detail?name=Data_compression_using_Zopfli.pdf&can=2&q=">
+Data_compression_using_Zopfli.pdf</a>
+<li><a href="http://zlib.net/pigz/">zlib.net/pigz</a> (parallel gzip)
+<li><a href="http://zlib.net/zlib/">zlib.net</a> (zlib/examples/zpipe.c)
+<li><a href="http://pmt.sourceforge.net/pngcrush/">pngcrush</a>
+<li><a href="http://libpng.sourceforge.net/>pngfix</a>
+(in contrib/tools of libpng-1.6.3 or later)
+</ul>
+</body>
+</html>

pngzop_zlib_to_idat.c

@@ -0,0 +1,95 @@
+/* pngzopz2i */
+
+/* Copyright 2013 Glenn Randers-Pehrson
+ * Released under the pngcrush license (equivalent to the libpng license)
+ */
+
+/* Usage:            
+ * pngzop_zlib_to_idat < file.zlib > file_out.idat
+ *
+ * file.zlib is the zlib datastream from zopli --zlib file_in.idat
+ * file_out.idat is the zlib datastream enclosed in PNG IDAT chunks.
+ * This is a single file that may contain multiple IDAT chunks.
+ *
+ * To do: make the maximum IDAT chunk data length an option (currently fixed
+ * at 250000 bytes).
+ *
+ */
+
+#include <stdio.h>
+
+#include <zlib.h> /* for crc32 */
+
+void
+put_uLong(uLong val)
+{
+   putchar(val >> 24);
+   putchar(val >> 16);
+   putchar(val >>  8);
+   putchar(val >>  0);
+}
+
+void
+put_chunk(const unsigned char *chunk, uInt length)
+{
+   uLong crc;
+
+   put_uLong(length-4); /* Exclude the tag */
+   fwrite(chunk, 1, length, stdout);
+
+   crc = crc32(0, Z_NULL, 0);
+   put_uLong(crc32(crc, chunk, length));
+}
+
+int
+main()
+{
+   unsigned char buf[250000];
+   int c;
+   const unsigned char idat[] = { 73, 68, 65, 84 /* "IDAT" */ };
+   int n=6;
+
+   /* IDAT */
+   buf[0]=idat[0];
+   buf[1]=idat[1];
+   buf[2]=idat[2];
+   buf[3]=idat[3];
+
+   /* CMF */
+   c=getchar();
+   if (c != EOF)
+     buf[4]=(unsigned char) c;
+
+   /* FLAGS */
+   if (c != EOF)
+   {
+     c=getchar();
+     if (c != EOF)
+       buf[5]=(unsigned char) c;
+   }
+
+   if (c != EOF)
+   for(;;)
+   {
+      /* read up to n=250000 bytes */
+
+      c=getchar();
+
+      if (c != EOF)
+      {
+        buf[n]=(unsigned char) c;
+        n++;
+      }
+
+      if (c != EOF && n < 250000)
+        continue;
+
+      put_chunk(buf, n);
+
+      if (c == EOF)
+        break;
+
+      n=4;
+   }
+}
+