1 <!-- Creator     : groff version 1.18.1 --> 
   2 <!-- CreationDate: Mon Mar 13 18:03:13 2006 --> 
   5 <meta name=
"generator" content=
"groff -Thtml, see www.gnu.org"> 
   6 <meta name=
"Content-Style" content=
"text/css"> 
   7 <title>TIFFMEDIAN
</title> 
  11 <h1 align=center
>TIFFMEDIAN
</h1> 
  12 <a href=
"#NAME">NAME
</a><br> 
  13 <a href=
"#SYNOPSIS">SYNOPSIS
</a><br> 
  14 <a href=
"#DESCRIPTION">DESCRIPTION
</a><br> 
  15 <a href=
"#OPTIONS">OPTIONS
</a><br> 
  16 <a href=
"#NOTES">NOTES
</a><br> 
  17 <a href=
"#SEE ALSO">SEE ALSO
</a><br> 
  23 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
  24        cols=
"2" cellspacing=
"0" cellpadding=
"0"> 
  25 <tr valign=
"top" align=
"left"> 
  28 <p>tiffmedian 
− apply the median cut algorithm to data
 
  29 in a 
<small>TIFF
</small> file
</p> 
  32 <a name=
"SYNOPSIS"></a> 
  35 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
  36        cols=
"2" cellspacing=
"0" cellpadding=
"0"> 
  37 <tr valign=
"top" align=
"left"> 
  40 <p><b>tiffmedian
</b> [ 
<i>options
</i> ] 
<i>input.tif
 
  44 <a name=
"DESCRIPTION"></a> 
  47 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
  48        cols=
"2" cellspacing=
"0" cellpadding=
"0"> 
  49 <tr valign=
"top" align=
"left"> 
  52 <p><i>tiffmedian
</i> applies the median cut algorithm to an
 
  53 <small>RGB
</small> image in 
<i>input.tif
</i> to generate a
 
  54 palette image that is written to 
<i>output.tif
</i>. The
 
  55 generated colormap has, by default, 
256 entries. The image
 
  56 data is quantized by mapping each pixel to the closest color
 
  57 values in the colormap.
</p> 
  60 <a name=
"OPTIONS"></a> 
  63 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
  64        cols=
"5" cellspacing=
"0" cellpadding=
"0"> 
  65 <tr valign=
"top" align=
"left"> 
  69 <p><b>−c
</b></p> 
  74 <p>Specify the compression to use for data written to the
 
  75 output file: 
<b>none
</b> for no compression, 
<b>packbits
</b> 
  76 for PackBits compression, 
<b>lzw
</b> for Lempel-Ziv 
& 
  77 Welch compression, and 
<b>zip
</b> for Deflate compression.
 
  78 By default 
<i>tiffmedian
</i> will compress data according to
 
  79 the value of the 
<i>Compression
</i> tag found in the source
 
  86 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
  87        cols=
"2" cellspacing=
"0" cellpadding=
"0"> 
  88 <tr valign=
"top" align=
"left"> 
  91 <p><small>LZW
</small> compression can be specified together
 
  92 with a 
<i>predictor
</i> value. A predictor value of 
2 causes
 
  93 each scanline of the output image to undergo horizontal
 
  94 differencing before it is encoded; a value of 
1 forces each
 
  95 scanline to be encoded without differencing. LZW-specific
 
  96 options are specified by appending a
 
  97 ‘‘:
’’-separated list to the
 
  98 ‘‘lzw
’’ option; e.g. 
<b>−c
 
  99 lzw:
2</b> for 
<small>LZW
</small> compression with horizontal
 
 104 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
 105        cols=
"5" cellspacing=
"0" cellpadding=
"0"> 
 106 <tr valign=
"top" align=
"left"> 
 107 <td width=
"10%"></td> 
 110 <p><b>−C
</b></p> 
 115 <p>Specify the number of entries to use in the generated
 
 116 colormap. By default all 
256 entries/colors are used.
</p> 
 120 <tr valign=
"top" align=
"left"> 
 121 <td width=
"10%"></td> 
 124 <p><b>−f
</b></p> 
 129 <p>Apply Floyd-Steinberg dithering before selecting a
 
 134 <tr valign=
"top" align=
"left"> 
 135 <td width=
"10%"></td> 
 138 <p><b>−r
</b></p> 
 143 <p>Specify the number of rows (scanlines) in each strip of
 
 144 data written to the output file. By default,
 
 145 <i>tiffmedian
</i> attempts to set the rows/strip that no
 
 146 more than 
8 kilobytes of data appear in a strip.
</p> 
 154 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
 155        cols=
"2" cellspacing=
"0" cellpadding=
"0"> 
 156 <tr valign=
"top" align=
"left"> 
 159 <p>This program is derived from Paul Heckbert
’s
 
 160 <i>median
</i> program.
</p> 
 163 <a name=
"SEE ALSO"></a> 
 166 <table width=
"100%" border=
0 rules=
"none" frame=
"void" 
 167        cols=
"2" cellspacing=
"0" cellpadding=
"0"> 
 168 <tr valign=
"top" align=
"left"> 
 171 <p><b>pal2rgb
</b>(
1), 
<b>tiffinfo
</b>(
1), 
<b>tiffcp
</b>(
1),
 
 172 <b>tiffcmp
</b>(
1), 
<b>libtiff
</b>(
3TIFF)
</p> 
 174 <p><b>Color Image Quantization for Frame Buffer Display
</b>,
 
 175 Paul Heckbert, SIGGRAPH proceedings, 
1982, pp. 
297-
307.
</p> 
 177 <p>Libtiff library home page:
 
 178 <b>http://www.remotesensing.org/libtiff/
</b></p>