NAME
    fax2tiff - create a TIFF Class F fax file from raw fax data

SYNOPSIS
    fax2tiff [ options ] [ -o output.tif ] input.g3

DESCRIPTION
    Fax2tiff  creates a TIFF file  containing CCITT Group 3 or Group 4
    encoded data from one or more files containing ``raw'' Group 3 encoded
    data (typically obtained directly from a fax modem). By default, each
    row of data in the resultant TIFF file is 2-dimensionally encoded and
    padded or truncated to 1728 pixels, as needed. The resultant image is
    a set of low resolution (98 lines/inch) or medium resolution (196
    lines/inch) pages, each of which is a single strip of data. The gener-
    ated file conforms to the TIFF Class F (FAX) specification for storing
    facsimile data.  This means, in particular, that each page of the data
    does not include the trailing return to control (RTC) code; as required
    for transmission by the CCITT Group 3 specifications. The old, ``clas-
    sic'', format is created if the -c option is used. (The Class F format
    can also be requested with the -f option.)

    The default name of the output image is fax.tif; this can be changed
    with the -o option. Each input file is assumed to be a separate page
    of facsimile data from the same document. The order in which input
    files are specified on the command line is the  order in which the
    resultant pages appear in the output file.

OPTIONS
    Options that affect the interpretation of input data are:

    -2   Assume input data is 2-d Huffman encoded.

    -B   Assume input data was encoded with black as 0 and white as 1.

    -L   Treat input data as having bits filled from least significant
    bit (LSB) to most significant bit (MSB). (This is the default.)

    -M   Treat input data as having bits filled from most significant bit
    (MSB) to most least bit (LSB).

    -R   Specify the vertical resolution, in lines/inch, of the  input
    images. By default input are assumed to have a vertical resolu-
    tion of 196 lines/inch. If images are low resolution facsimile,
    a value of 98 lines/inch should be specified.

    -W   Assume input data was encoded with black as 1 and white as 0.
    (This is the default.)

    Options that affect the output file format are:

    -1   Force output to be compressed with the 1-dimensional version of
    the CCITT Group 3 Huffman encoding algorithm.

    -4   Force output to  be compressed with the CCITT Group 4 Huffman
    encoding.

    -o   Specify the name of the output file.

    -p   Force the last bit of each End Of Line (EOL) code to land  on a
    byte boundary. This ``zero padding'' will be reflected in the
    contents of the Group3Options tag of the resultant TIFF file.

    -s   Stretch the input image vertically by writing each input row of
    data twice to the output file.

    -v   Force fax2tiff to print the number of rows of data it retrieved
    from the input file.

DIAGNOSTICS
    The following warnings and errors come from the decoding routines in
    the library.

    Warning,  %s: Premature  EOL at scanline %d (x %d).\n. The input data
    had a row that was shorter than the expected value of 1728. The row is
    padded with white.

    %s: Premature EOF at scanline %d (x %d).\n. The decoder ran out of
    data in the middle of a scanline. The resultant  row is padded with
    white.

    %s: Bad  code word at  row %d, x %d\n. An invalid Group 3 code was
    encountered while decoding the input file. The row number and horizon-
    tal position is given. The remainder of the input row is discarded,
    while the corresponding output row is padded with white.

    %s: Bad 2D code word at scanline %d.\n. An invalid Group 4 or 2D Group
    3 code was encountered while decoding the input file. The row number
    and horizontal position is given. The remainder of the input row is
    discarded, while the corresponding output row is padded with white.

BUGS
    Should not have the constant width 1728 built into it. Input data are
    assumed to have a a ``top left'' orientation; it should be possible to
    override this assumption from the command line.

SEE ALSO
    CCITT Recommendation T.4 (Standardization of Group 3 Facsimile Appara-
    tus for Document Transmission).

    The Spirit of TIFF Class F, an appendix to the TIFF 5.0  specification
    prepared by Cygnet Technologies.

   tiffinfo(1),tiffdither(1),tiffgt(1), libtiff(3).