tiffdither - convert a greyscale image to bilevel using dithering
tiffdither [ options ] input.tif output.tif
TIFFDITHER(1) General Commands Manual TIFFDITHER(1)
NAME
tiffdither - convert a greyscale image to bilevel using dithering
SYNOPSIS
tiffdither [ options ] input.tif output.tif
DESCRIPTION
tiffdither converts a single channel 8-bit greyscale image to a bilevel
image using Floyd-Steinberg error propagation with thresholding.
OPTIONS
-c Specify the compression to use for data written to the output
file: none for no compression, packbits for PackBits compres-
sion, lzw for Lempel-Ziv & Welch compression, zip for Deflate
compression, g3 for CCITT Group 3 (T.4) compression, and g4 for
CCITT Group 4 (T.6) compression. By default tiffdither will
compress data according to the value of the Compression tag
found in the source file.
The CCITT Group 3 and Group 4 compression algorithms can only be
used with bilevel data.
Group 3 compression can be specified together with several
T.4-specific options: 1d for 1-dimensional encoding, 2d for
2-dimensional encoding, and fill to force each encoded scanline
to be zero-filled so that the terminating EOL code lies on a
byte boundary. Group 3-specific options are specified by
appending a ``:''-separated list to the ``g3'' option; e.g. -c
g3:2d:fill to get 2D-encoded data with byte-aligned EOL codes.
LZW compression can be specified together with a predictor
value. A predictor value of 2 causes each scanline of the out-
put image to undergo horizontal differencing before it is
encoded; a value of 1 forces each scanline to be encoded without
differencing. LZW-specific options are specified by appending a
``:''-separated list to the ``lzw'' option; e.g. -c lzw:2 for
LZW compression with horizontal differencing.
-f Specify the bit fill order to use in writing output data. By
default, tiffdither will create a new file with the same fill
order as the original. Specifying -f lsb2msb will force data to
be written with the FillOrder tag set to LSB2MSB , while -f
msb2lsb will force data to be written with the FillOrder tag set
to MSB2LSB .
-r Make each strip have no more than the given number of rows.
-t Set the threshold value for dithering. By default the threshold
value is 128.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+-----------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------------+
|Availability | image/library/libtiff |
+---------------+-----------------------+
|Stability | Volatile |
+---------------+-----------------------+
NOTES
The dither algorithm is taken from the tiffmedian(1) program (written
by Paul Heckbert).
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from http://down-
load.osgeo.org/libtiff/tiff-4.2.0.tar.gz.
Further information about this software can be found on the open source
community website at http://www.simplesystems.org/libtiff/.
SEE ALSO
pal2rgb(1), fax2tiff(1), tiffinfo(1), tiffcp(1), tiff2bw(1),
libtiff(3TIFF)
Libtiff library home page: http://www.simplesystems.org/libtiff/
libtiff September 20, 2005 TIFFDITHER(1)