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diff --git a/tiff/man/tiffdither.1 b/tiff/man/tiffdither.1 new file mode 100644 index 0000000..0e1294c --- /dev/null +++ b/tiff/man/tiffdither.1 @@ -0,0 +1,132 @@ +.\" $Id: tiffdither.1,v 1.4 2006/04/20 12:17:19 dron 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 advertising or +.\" publicity relating to the software without the specific, prior written +.\" permission of Sam Leffler and Silicon Graphics. +.\" +.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, +.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY +.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. +.\" +.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR +.\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, +.\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, +.\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF +.\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE +.\" OF THIS SOFTWARE. +.\" +.if n .po 0 +.TH TIFFDITHER 1 "September 20, 2005" "libtiff" +.SH NAME +tiffdither \- convert a greyscale image to bilevel using dithering +.SH SYNOPSIS +.B tiffdither +[ +.I options +] +.I input.tif +.I output.tif +.SH DESCRIPTION +.I tiffdither +converts a single channel 8-bit greyscale image to a bilevel image +using Floyd-Steinberg error propagation with thresholding. +.SH OPTIONS +.TP +.B \-c +Specify the compression to use for data written to the output file: +.B none +for no compression, +.B packbits +for PackBits compression, +.B lzw +for Lempel-Ziv & Welch compression, +.B zip +for Deflate compression, +.B g3 +for CCITT Group 3 (T.4) compression, +and +.B g4 +for CCITT Group 4 (T.6) compression. +By default +.I tiffdither +will compress data according to the value of the +.I Compression +tag found in the source file. +.IP +The +.SM CCITT +Group 3 and Group 4 compression algorithms can only +be used with bilevel data. +.IP +Group 3 compression can be specified together with several +T.4-specific options: +.B 1d +for 1-dimensional encoding, +.B 2d +for 2-dimensional encoding, +and +.B 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. +.B "\-c g3:2d:fill" +to get 2D-encoded data with byte-aligned EOL codes. +.IP +.SM LZW +compression can be specified together with a +.I 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. +.B "\-c lzw:2" +for +.SM LZW +compression with horizontal differencing. +.TP +.B \-f +Specify the bit fill order to use in writing output data. +By default, +.I tiffdither +will create a new file with the same fill order as the original. +Specifying +.B "\-f lsb2msb" +will force data to be written with the +.I Fill\%Order +tag set to +.SM LSB2MSB , +while +.B "\-f msb2lsb" +will force data to be written with the +.I Fill\%Order +tag set to +.SM MSB2LSB . +.TP +.B \-t +Set the threshold value for dithering. +By default the threshold value is 128. +.SH NOTES +The dither algorithm is taken from the +.BR tiffmedian (1) +program (written by Paul Heckbert). +.SH "SEE ALSO" +.BR pal2rgb (1), +.BR fax2tiff (1), +.BR tiffinfo (1), +.BR tiffcp (1), +.BR tiff2bw (1), +.BR libtiff (3TIFF) +.PP +Libtiff library home page: +.BR http://www.remotesensing.org/libtiff/ |