                      ===================================
                      AdvanceCOMP PNG Compression Utility
                      ===================================


1 SYNOPSIS
==========

advpng [-l, --list] [-z, --recompress] [-0, --shrink-0]
	[-1, --shrink-fast] [-2, --shrink-normal [-3, --shrink-extra]
	[-4, --shrink-insane] [-i, --iter N]
	[-f, --force] [-q, --quiet]
	[-h, --help] [-V, --version] FILES...


2 DESCRIPTION
=============

The main purpose of this utility is to recompress png
files to get the smallest possible size.

Please note that this utility is not able to read
a generic file. It's granted to be able to read only
the files generated by the AdvanceMAME emulator.

To compress the files this utility uses the following
strategies:

* Remove all ancillary chunks.
* Concatenate all the IDAT chunks.
* Use the 7zip Deflate implementation.


3 OPTIONS
=========

    -l, --list FILES...
        List the content of the specified files.

    -z, --recompress FILES...
        Recompress the specified files. If the -1, -2, -3
        options are specified it's used the smallest file
        choice from the previous compressed data and the
        new compression. If the -0 option is specified the
        file is always rewritten without any compression.

    -0, --shrink-store
        Disable the compression. The file is
        only stored and not compressed. The file is always
        rewritten also if it's bigger.

    -1, --shrink-fast
        Set the compression level to "fast" using the zlib
        compressor.

    -2, --shrink-normal
        Set the compression level to "normal" using the libdeflate
        compressor.
        This is the default level of compression.

    -3, --shrink-extra
        Set the compression level to "extra" using the 7z
        compressor.
        You can define the compressor iterations with
        the -i, --iter option.

    -4, --shrink-insane
        Set the compression level to "insane" using the zopfli
        compressor.
        You can define the compressor iterations with
        the -i, --iter option.

    -i, --iter N
        Define an additional numer of iterations for the 7z and zopfli
        compressors for modes -3 and -4.
        More iterations usually give a better compression, but may
        require a lot more time.
        Try for example with 10, 15, 20, and so on.

    -f, --force
        Force the use of the new file also if it's bigger.


4 COPYRIGHT
===========

This file is Copyright (C) 2002 Andrea Mazzoleni, Filipe Estima


5 SEE ALSO
==========

advzip(1), advmng(1), advdef(1)
