tiffmedian - apply the median cut algorithm to data in a TIFF file
tiffmedian [ options ] input.tif output.tif
TIFFMEDIAN(1) General Commands Manual TIFFMEDIAN(1)
NAME
tiffmedian - apply the median cut algorithm to data in a TIFF file
SYNOPSIS
tiffmedian [ options ] input.tif output.tif
DESCRIPTION
tiffmedian applies the median cut algorithm to an RGB image in
input.tif to generate a palette image that is written to output.tif.
The generated colormap has, by default, 256 entries. The image data is
quantized by mapping each pixel to the closest color values in the col-
ormap.
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, and zip for
Deflate compression. By default tiffmedian will compress data
according to the value of the Compression tag found in the
source file.
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.
-C Specify the number of entries to use in the generated colormap.
By default all 256 entries/colors are used.
-f Apply Floyd-Steinberg dithering before selecting a colormap
entry.
-r Specify the number of rows (scanlines) in each strip of data
written to the output file. By default, tiffmedian attempts to
set the rows/strip that no more than 8 kilobytes of data appear
in a strip.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+-----------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------------+
|Availability | image/library/libtiff |
+---------------+-----------------------+
|Stability | Volatile |
+---------------+-----------------------+
NOTES
This program is derived from Paul Heckbert's median program.
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), tiffinfo(1), tiffcp(1), tiffcmp(1), libtiff(3TIFF)
Color Image Quantization for Frame Buffer Display, Paul Heckbert, SIG-
GRAPH proceedings, 1982, pp. 297-307.
Libtiff library home page: http://www.simplesystems.org/libtiff/
libtiff November 2, 2005 TIFFMEDIAN(1)