[pngzop] Updated pngzop_README.txt with license and disclaimer.
diff --git a/pngzop_README.txt b/pngzop_README.txt
index f4d6a93..546383d 100644
--- a/pngzop_README.txt
+++ b/pngzop_README.txt
@@ -1,9 +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 will be incorporated
+ 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 libpng
+ license plus required 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 "-ext 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 pngcrush computer program 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 computer program, even if advised of the possibility of such damage.
+ There is no warranty against interference with your enjoyment of the
+ computer program or against infringement. There is no warranty that my
+ efforts or the computer program will fulfill any of your particular purposes
+ or needs. This computer program 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.
*/
