tiffmedian (1)

Leading comments

$Id: tiffmedian.1,v 1.4 2016-09-25 20:05:52 bfriesen Exp $

Copyright (c) 1990-1997 Sam Leffler
Copyright (c) 1991-1997 Silicon Graphics, Inc.

Permission to use, copy, modify, distribute, and sell this software and
its documentation for any purpose is hereby granted without fee, provided
that (i) the above copyright notices and this permission notice appear in
all copies of the software and related documentation, and (ii) the names of
Sam Leffler and Silicon Graphics may not be used in any a...

(The comments found at the beginning of the groff file "man1/tiffmedian.1".)

NAME

tiffmedian - apply the median cut algorithm to data in a file

SYNOPSIS

tiffmedian [ options ] input.tif output.tif

DESCRIPTION

tiffmedian applies the median cut algorithm to an 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 colormap.

OPTIONS

-c

Specify the compression to use for data written to the output file: none for no compression, packbits for PackBits compression, 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 output 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.

NOTES

This program is derived from Paul Heckbert's median program.

SEE ALSO

pal2rgb(1), tiffinfo(1), tiffcp(1), tiffcmp(1), libtiff(3TIFF)

Color Image Quantization for Frame Buffer Display, Paul Heckbert, SIGGRAPH proceedings, 1982, pp. 297-307.

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