FAX2PNG(1)                BSD General Commands Manual               FAX2PNG(1)

NAME
     fax2png -- 1-bit multipage TIFF (fax) ``to PNG image
     converter''

SYNOPSIS
     fax2png tifffilename [pngfilename] [-p pagenumber] [-w
             width]
                     [-r 0|90|180|270] [-lr] [-tb] [-a]

EXAMPLE
     fax2png fax.tiff page2.png -p 2 -w 600 -a

VERSION
     Version 1.0, 01/27/2004.

DESCRIPTION
     fax2png Extracts a specified page from a 1-bit black and
     white TIFF image, such as a fax, and efficiently converts
     it to PNG format without the performance overhead of
     netpbm-based solutions. Antialiasing is supported to pro-
     duce attractive reductions to typical web browser widths,
     as in the example above. 90-degree-interval rotations and
     flips are also supported. While all of the above can be
     performed with netpbm and related utilities, fax2png is
     much more efficient in time and memory usage.

INPUT FILE
     The input file must be in TIFF format, and must contain
     one or more single-bit images (black and white, such as a
     G3 fax file). Color images are not supported. If your TIFF
     files are not faxes or black and white document scans, you
     should use the slower but more general tifftopnm utility.

OUTPUT FILE
     You may specify an output file name, such as myfile.png.
     If you do not specify a file name, a PNG format image is
     written to standard output.

PAGE NUMBER
     You may indicate the desired page number with the -p
     option. Pages are numbered beginning with page 1. If you
     do not specify a page number, the first page is converted.

OUTPUT WIDTH
     You may select the width of the output image with the -w
     option. If you do not specify the width, the width of the
     output will be the same as the width of the input. This is
     usually much too wide for typical applications. -w 600 -a
     is suggested for web browser display purposes.  The height
     of the output image will be reduced by the same propor-
     tion.

ROTATION
     You may specify rotation with the -r option. You may
     rotate by 0, 90, 180, or 270 degrees. If you do not use
     the -r option, no rotation is performed.

FLIPPING
     You may flip (mirror) the image from left to right by
     specifying the -lr option. Vertical flipping is accom-
     plished using the -tb option.

ANTIALIASING (RESAMPLING)
     When specifying the -w option to reduce size, it is almost
     always appropriate to also specify the -a option. When the
     -a option is used, the relevant input pixels are averaged
     to compute the value of the output pixel, producing high-
     quality output. Without -a, drastic size reductions (such
     as those necessary for onscreen display of faxes) are very
     unattractive.

LIMITATIONS
     fax2png does not process color TIFFs, grayscale TIFFs with
     more than two shades of grey (black and white), or any
     TIFF file that Leffler's TIFF Library cannot handle.
     That's why it is not called tiff2png.

BUGS
     Combining rotation and flipping in a single command line
     may produce counterintuitive results.

LICENSE
     Copyright 2004, Boutell.Com, Inc. and Tobacco Documents
     Online.  This software is released for free use under the
     terms of the GNU Public License, version 2 or higher. NO
     WARRANTY IS EXPRESSED OR IMPLIED. USE THIS SOFTWARE AT
     YOUR OWN RISK.

CONTACT INFORMATION
     See http://www.boutell.com/fax2png/ for the latest release
     and contact information.

THANKS
     Thanks are due to Tobacco Documents Online for graciously
     allowing this work to be made available as open source
     following its completion for their use. Thanks are also
     due to Sam Leffler for his excellent TIFF library, as well
     as the authors of the PNG and ZLIB libraries.


LINUX                         January 27th, 2004                         LINUX
