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Updated: Thursday, June 13, 2019
 
 

tiffdither (1)

Name

tiffdither - convert a greyscale image to bilevel using dithering

Synopsis

tiffdither [ options ] input.tif output.tif

Description

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).

SEE ALSO
       pal2rgb(1),   fax2tiff(1),    tiffinfo(1),    tiffcp(1),    tiff2bw(1),
       libtiff(3TIFF)

       Libtiff library home page: http://www.simplesystems.org/libtiff/


       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-4.0.10.tar.gz

       Further information about this software can be found on the open source
       community website at http://www.simplesystems.org/libtiff/.



libtiff                       September 20, 2005                 TIFFDITHER(1)