/
tiffdither.1.html
196 lines (186 loc) · 5.65 KB
/
tiffdither.1.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
<!-- Creator : groff version 1.18.1 -->
<!-- CreationDate: Sat Feb 24 18:37:20 2007 -->
<html>
<head>
<meta name="generator" content="groff -Thtml, see www.gnu.org">
<meta name="Content-Style" content="text/css">
<title>TIFFDITHER</title>
</head>
<body>
<h1 align=center>TIFFDITHER</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#OPTIONS">OPTIONS</a><br>
<a href="#NOTES">NOTES</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<hr>
<a name="NAME"></a>
<h2>NAME</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="8%"></td>
<td width="91%">
<p>tiffdither − convert a greyscale image to bilevel
using dithering</p>
</td>
</table>
<a name="SYNOPSIS"></a>
<h2>SYNOPSIS</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="8%"></td>
<td width="91%">
<p><b>tiffdither</b> [ <i>options</i> ] <i>input.tif
output.tif</i></p>
</td>
</table>
<a name="DESCRIPTION"></a>
<h2>DESCRIPTION</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="8%"></td>
<td width="91%">
<p><i>tiffdither</i> converts a single channel 8-bit
greyscale image to a bilevel image using Floyd-Steinberg
error propagation with thresholding.</p>
</td>
</table>
<a name="OPTIONS"></a>
<h2>OPTIONS</h2>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="5" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td>
<td width="2%">
<p><b>−c</b></p>
</td>
<td width="6%"></td>
<td width="80%">
<p>Specify the compression to use for data written to the
output file: <b>none</b> for no compression, <b>packbits</b>
for PackBits compression, <b>lzw</b> for Lempel-Ziv &
Welch compression, <b>zip</b> for Deflate compression,
<b>g3</b> for CCITT Group 3 (T.4) compression, and <b>g4</b>
for CCITT Group 4 (T.6) compression. By default
<i>tiffdither</i> will compress data according to the value
of the <i>Compression</i> tag found in the source file.</p>
</td>
<td width="0%">
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="17%"></td>
<td width="82%">
<p>The <small>CCITT</small> Group 3 and Group 4 compression
algorithms can only be used with bilevel data.</p>
<!-- INDENTATION -->
<p>Group 3 compression can be specified together with
several T.4-specific options: <b>1d</b> for 1-dimensional
encoding, <b>2d</b> for 2-dimensional encoding, and
<b>fill</b> 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</b> to get 2D-encoded data with byte-aligned EOL
codes.</p>
<!-- INDENTATION -->
<p><small>LZW</small> compression can be specified together
with a <i>predictor</i> 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</b> for <small>LZW</small> compression with horizontal
differencing.</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="5" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td>
<td width="3%">
<p><b>−f</b></p>
</td>
<td width="5%"></td>
<td width="80%">
<p>Specify the bit fill order to use in writing output
data. By default, <i>tiffdither</i> will create a new file
with the same fill order as the original. Specifying
<b>−f lsb2msb</b> will force data to be written with
the <i>FillOrder</i> tag set to <small>LSB2MSB ,</small>
while <b>−f msb2lsb</b> will force data to be written
with the <i>Fill- Order</i> tag set to <small>MSB2LSB
.</small></p>
</td>
<td width="0%">
</td>
<tr valign="top" align="left">
<td width="10%"></td>
<td width="3%">
<p><b>−r</b></p>
</td>
<td width="5%"></td>
<td width="80%">
<p>Make each strip have no more than the given number of rows.</p>
</td>
<td width="0%">
</td>
<tr valign="top" align="left">
<td width="10%"></td>
<td width="3%">
<p><b>−t</b></p>
</td>
<td width="5%"></td>
<td width="80%">
<p>Set the threshold value for dithering. By default the
threshold value is 128.</p>
</td>
<td width="0%">
</td>
</table>
<a name="NOTES"></a>
<h2>NOTES</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="8%"></td>
<td width="91%">
<p>The dither algorithm is taken from the
<b>tiffmedian</b>(1) program (written by Paul Heckbert).</p>
</td>
</table>
<a name="SEE ALSO"></a>
<h2>SEE ALSO</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="8%"></td>
<td width="91%">
<p><b>pal2rgb</b>(1), <b>fax2tiff</b>(1),
<b>tiffinfo</b>(1), <b>tiffcp</b>(1), <b>tiff2bw</b>(1),
<b>libtiff</b>(3TIFF)</p>
<!-- INDENTATION -->
<p>Libtiff library home page:
<b>http://www.simplesystems.org/libtiff/</b></p>
</td>
</table>
<hr>
</body>
</html>