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fax2tiff - create a TIFF
Class F fax file
from raw fax data
fax2tiff [ options ] [ -o output.tif ] input.raw
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 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.
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.
Input data are assumed to have a a ‘‘top left’’ orientation;
it should be possible to override this assumption from the command line.
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/
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