FAX2TIFF(1)                                           FAX2TIFF(1)

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 sin-
       gle strip of data.  The generated  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, ``classic'', 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 doc-
       ument.  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 resolution 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-dimen-
              sional version of the CCITT Group 3 Huffman  encod-
              ing 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 resul-
       tant 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 horizontal position is given.  The  remain-
       der 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'' orienta-
       tion; it should be possible to  override  this  assumption
       from the command line.

SEE ALSO
       CCITT  Recommendation T.4 (Standardization of Group 3 Fac-
       simile Apparatus 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).

                        September 24, 1994                      1