NAME
fax2tiff - create a TIFF Class F fax file from raw fax data
SYNOPSIS
fax2tiff [ options ] [ -o output.tif ] input.raw
DESCRIPTION
Fax2tiff creates a TIFF file containing CCITT Group 3 or Group 4
encoded data from one or more files containing ``raw'' Group 3 or Group
4 encoded data (typically obtained directly from a fax modem). By
default, each row of data in the resultant TIFF file is 1-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 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 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:
-3 Assume input data is CCITT Group 3 encoded (default).
-4 Assume input data is CCITT Group 4 encoded.
-U Assume input data is uncompressed (Group 3 or Group 4).
-1 Assume input data is encoded with the 1-dimensional version of
the CCITT Group 3 Huffman encoding algorithm (default).
-2 Assume input data is 2-dimensional version of the CCITT Group 3
Huffman encoding algorithm.
-P Assume input data is not EOL-aligned (default). This option has
effect with Group 3 encoded input only.
-A Assume input data is EOL-aligned. This option has effect with
Group 3 encoded input only.
-M Treat input data as having bits filled from most significant bit
(MSB) to most least bit (LSB).
-L Treat input data as having bits filled from least significant
bit (LSB) to most significant bit (MSB) (default).
-B Assume input data was encoded with black as 0 and white as 1.
-W Assume input data was encoded with black as 1 and white as 0
(default).
-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.
-X Specify the width, in pixels, of the input images. By default
input are assumed to have a width of 1728 pixels.
Options that affect the output file format are:
-o Specify the name of the output file.
-7 Force output to be compressed with the CCITT Group 3 Huffman
encoding algorithm (default).
-8 Force output to be compressed with the CCITT Group 4 Huffman
encoding.
-u Force output to be uncompressed (Group 3 or Group 4).
-5 Force output to be encoded with the 1-dimensional version of the
CCITT Group 3 Huffman encoding algorithm.
-6 Force output to be encoded with the 2-dimensional version of the
CCITT Group 3 Huffman encoding algorithm (default).
-a Force the last bit of each End Of Line (EOL) code to land on a
byte boundary (default). This ``zero padding'' will be reflected
in the contents of the Group3Options tag of the resultant TIFF
file. This option has effect with Group 3 encoded output only.
-p Do not EOL-align output. This option has effect with Group 3
encoded output only.
-c Generate "classic" Group 3 TIFF format.
-f Generate TIFF Class F (TIFF/F) format (default).
-m Force output data to have bits filled from most significant bit
(MSB) to most least bit (LSB).
-l Force output data to have bits filled from least significant
bit (LSB) to most significant bit (MSB) (default).
-r Specify the number of rows (scanlines) in each strip of data
written to the output file. By default (or when value 0 is
specified), tiffcp attempts to set the rows/strip that no more
than 8 kilobytes of data appear in a strip (with except of G3/G4
compression schemes). If you specify special value -1 it will
results in infinite number of the rows per strip. The entire
image will be the one strip in that case. This is default in
case of G3/G4 output compression schemes.
-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.
-z Force output to be compressed with the LZW encoding.
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 width. 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
horizontal 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
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
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)
Libtiff library home page: http://www.remotesensing.org/libtiff/