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1 | <!-- Creator : groff version 1.18.1 --> |
2 | <!-- CreationDate: Mon Mar 13 18:03:10 2006 --> | |
3 | <html> | |
4 | <head> | |
5 | <meta name="generator" content="groff -Thtml, see www.gnu.org"> | |
6 | <meta name="Content-Style" content="text/css"> | |
7 | <title>TIFFReadRGBATile</title> | |
8 | </head> | |
9 | <body> | |
10 | ||
11 | <h1 align=center>TIFFReadRGBATile</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="#NOTES">NOTES</a><br> | |
16 | <a href="#RETURN VALUES">RETURN VALUES</a><br> | |
17 | <a href="#DIAGNOSTICS">DIAGNOSTICS</a><br> | |
18 | <a href="#SEE ALSO">SEE ALSO</a><br> | |
19 | ||
20 | <hr> | |
21 | <a name="NAME"></a> | |
22 | <h2>NAME</h2> | |
23 | <!-- INDENTATION --> | |
24 | <table width="100%" border=0 rules="none" frame="void" | |
25 | cols="2" cellspacing="0" cellpadding="0"> | |
26 | <tr valign="top" align="left"> | |
27 | <td width="8%"></td> | |
28 | <td width="91%"> | |
29 | <p>TIFFReadRGBATile − read and decode an image tile | |
30 | into a fixed-format raster</p> | |
31 | </td> | |
32 | </table> | |
33 | <a name="SYNOPSIS"></a> | |
34 | <h2>SYNOPSIS</h2> | |
35 | <!-- INDENTATION --> | |
36 | <table width="100%" border=0 rules="none" frame="void" | |
37 | cols="2" cellspacing="0" cellpadding="0"> | |
38 | <tr valign="top" align="left"> | |
39 | <td width="8%"></td> | |
40 | <td width="91%"> | |
41 | <p><b>#include <tiffio.h></b></p> | |
42 | </td> | |
43 | </table> | |
44 | <!-- TABS --> | |
45 | <table width="100%" border=0 rules="none" frame="void" | |
46 | cols="5" cellspacing="0" cellpadding="0"> | |
47 | <tr valign="top" align="left"> | |
48 | <td width="8%"></td> | |
49 | <td width="-2%"> | |
50 | ||
51 | <p><b>#define TIFFGetR(abgr)</b></p> | |
52 | </td> | |
53 | <td width="25%"></td> | |
54 | <td width="6%"></td> | |
55 | <td width="61%"> | |
56 | ||
57 | <p><b>((abgr) & 0xff)</b></p> | |
58 | </td> | |
59 | <tr valign="top" align="left"> | |
60 | <td width="8%"></td> | |
61 | <td width="-2%"> | |
62 | ||
63 | <p><b>#define TIFFGetG(abgr)</b></p> | |
64 | </td> | |
65 | <td width="25%"></td> | |
66 | <td width="6%"></td> | |
67 | <td width="61%"> | |
68 | ||
69 | <p><b>(((abgr) >> 8) & 0xff)</b></p> | |
70 | </td> | |
71 | <tr valign="top" align="left"> | |
72 | <td width="8%"></td> | |
73 | <td width="-2%"> | |
74 | ||
75 | <p><b>#define TIFFGetB(abgr)</b></p> | |
76 | </td> | |
77 | <td width="25%"></td> | |
78 | <td width="6%"></td> | |
79 | <td width="61%"> | |
80 | ||
81 | <p><b>(((abgr) >> 16) & 0xff)</b></p> | |
82 | </td> | |
83 | <tr valign="top" align="left"> | |
84 | <td width="8%"></td> | |
85 | <td width="-2%"> | |
86 | ||
87 | <p><b>#define TIFFGetA(abgr)</b></p> | |
88 | </td> | |
89 | <td width="25%"></td> | |
90 | <td width="6%"></td> | |
91 | <td width="61%"> | |
92 | ||
93 | <p><b>(((abgr) >> 24) & 0xff)</b></p> | |
94 | </td> | |
95 | </table> | |
96 | <!-- INDENTATION --> | |
97 | <table width="100%" border=0 rules="none" frame="void" | |
98 | cols="2" cellspacing="0" cellpadding="0"> | |
99 | <tr valign="top" align="left"> | |
100 | <td width="8%"></td> | |
101 | <td width="91%"> | |
102 | <p><b>int TIFFReadRGBATile(TIFF *</b><i>tif</i><b>, | |
103 | uint32</b> <i>x</i><b>, uint32</b> <i>y</i><b>, uint32 | |
104 | *</b><i>raster</i><b>)</b></p> | |
105 | </td> | |
106 | </table> | |
107 | <a name="DESCRIPTION"></a> | |
108 | <h2>DESCRIPTION</h2> | |
109 | <!-- INDENTATION --> | |
110 | <table width="100%" border=0 rules="none" frame="void" | |
111 | cols="2" cellspacing="0" cellpadding="0"> | |
112 | <tr valign="top" align="left"> | |
113 | <td width="8%"></td> | |
114 | <td width="91%"> | |
115 | <p><i>TIFFReadRGBATile</i> reads a single tile of a | |
116 | tile-based image into memory, storing the result in the user | |
117 | supplied RGBA <i>raster</i>. The raster is assumed to be an | |
118 | array of width times length 32-bit entries, where width is | |
119 | the width of a tile (TIFFTAG_TILEWIDTH) and length is the | |
120 | height of a tile (TIFFTAG_TILELENGTH).</p> | |
121 | <!-- INDENTATION --> | |
122 | <p>The <i>x</i> and <i>y</i> values are the offsets from the | |
123 | top left corner to the top left corner of the tile to be | |
124 | read. They must be an exact multiple of the tile width and | |
125 | length.</p> | |
126 | <!-- INDENTATION --> | |
127 | <p>Note that the raster is assume to be organized such that | |
128 | the pixel at location (<i>x</i>,<i>y</i>) is | |
129 | <i>raster</i>[<i>y</i>*<i>width</i>+<i>x</i>]; with the | |
130 | raster origin in the <i>lower-left hand corner</i> of the | |
131 | tile. That is bottom to top organization. Edge tiles which | |
132 | partly fall off the image will be filled out with | |
133 | appropriate zeroed areas.</p> | |
134 | <!-- INDENTATION --> | |
135 | <p>Raster pixels are 8-bit packed red, green, blue, alpha | |
136 | samples. The macros <i>TIFFGetR</i>, <i>TIFFGetG</i>, | |
137 | <i>TIFFGetB</i>, and <i>TIFFGetA</i> should be used to | |
138 | access individual samples. Images without Associated Alpha | |
139 | matting information have a constant Alpha of 1.0 (255).</p> | |
140 | <!-- INDENTATION --> | |
141 | <p>See the <i>TIFFRGBAImage</i>(3TIFF) page for more details | |
142 | on how various image types are converted to RGBA values.</p> | |
143 | </td> | |
144 | </table> | |
145 | <a name="NOTES"></a> | |
146 | <h2>NOTES</h2> | |
147 | <!-- INDENTATION --> | |
148 | <table width="100%" border=0 rules="none" frame="void" | |
149 | cols="2" cellspacing="0" cellpadding="0"> | |
150 | <tr valign="top" align="left"> | |
151 | <td width="8%"></td> | |
152 | <td width="91%"> | |
153 | <p>Samples must be either 1, 2, 4, 8, or 16 bits. | |
154 | Colorimetric samples/pixel must be either 1, 3, or 4 (i.e. | |
155 | <i>SamplesPerPixel</i> minus <i>ExtraSamples</i>).</p> | |
156 | <!-- INDENTATION --> | |
157 | <p>Palette image colormaps that appear to be incorrectly | |
158 | written as 8-bit values are automatically scaled to | |
159 | 16-bits.</p> | |
160 | <!-- INDENTATION --> | |
161 | <p><i>TIFFReadRGBATile</i> is just a wrapper around the more | |
162 | general <i>TIFFRGBAImage</i>(3TIFF) facilities. It’s | |
163 | main advantage over the similar <i>TIFFReadRGBAImage()</i> | |
164 | function is that for large images a single buffer capable of | |
165 | holding the whole image doesn’t need to be allocated, | |
166 | only enough for one tile. The <i>TIFFReadRGBAStrip()</i> | |
167 | function does a similar operation for stripped images.</p> | |
168 | </td> | |
169 | </table> | |
170 | <a name="RETURN VALUES"></a> | |
171 | <h2>RETURN VALUES</h2> | |
172 | <!-- INDENTATION --> | |
173 | <table width="100%" border=0 rules="none" frame="void" | |
174 | cols="2" cellspacing="0" cellpadding="0"> | |
175 | <tr valign="top" align="left"> | |
176 | <td width="8%"></td> | |
177 | <td width="91%"> | |
178 | <p>1 is returned if the image was successfully read and | |
179 | converted. Otherwise, 0 is returned if an error was | |
180 | encountered.</p> | |
181 | </td> | |
182 | </table> | |
183 | <a name="DIAGNOSTICS"></a> | |
184 | <h2>DIAGNOSTICS</h2> | |
185 | <!-- INDENTATION --> | |
186 | <table width="100%" border=0 rules="none" frame="void" | |
187 | cols="2" cellspacing="0" cellpadding="0"> | |
188 | <tr valign="top" align="left"> | |
189 | <td width="8%"></td> | |
190 | <td width="91%"> | |
191 | <p>All error messages are directed to the | |
192 | <i>TIFFError</i>(3TIFF) routine.</p> | |
193 | <!-- INDENTATION --> | |
194 | <p><b>Sorry, can not handle %d-bit pictures</b>. The image | |
195 | had <i>BitsPerSample</i> other than 1, 2, 4, 8, or 16.</p> | |
196 | <!-- INDENTATION --> | |
197 | <p><b>Sorry, can not handle %d-channel images</b>. The image | |
198 | had <i>SamplesPerPixel</i> other than 1, 3, or 4.</p> | |
199 | <!-- INDENTATION --> | |
200 | <p><b>Missing needed "PhotometricInterpretation" | |
201 | tag</b>. The image did not have a tag that describes how to | |
202 | display the data.</p> | |
203 | <!-- INDENTATION --> | |
204 | <p><b>No "PhotometricInterpretation" tag, assuming | |
205 | RGB</b>. The image was missing a tag that describes how to | |
206 | display it, but because it has 3 or 4 samples/pixel, it is | |
207 | assumed to be <small>RGB.</small></p> | |
208 | <!-- INDENTATION --> | |
209 | <p><b>No "PhotometricInterpretation" tag, assuming | |
210 | min-is-black</b>. The image was missing a tag that describes | |
211 | how to display it, but because it has 1 sample/pixel, it is | |
212 | assumed to be a grayscale or bilevel image.</p> | |
213 | <!-- INDENTATION --> | |
214 | <p><b>No space for photometric conversion table</b>. There | |
215 | was insufficient memory for a table used to convert image | |
216 | samples to 8-bit <small>RGB.</small></p> | |
217 | <!-- INDENTATION --> | |
218 | <p><b>Missing required "Colormap" tag</b>. A | |
219 | Palette image did not have a required <i>Colormap</i> | |
220 | tag.</p> | |
221 | <!-- INDENTATION --> | |
222 | <p><b>No space for tile buffer</b>. There was insufficient | |
223 | memory to allocate an i/o buffer.</p> | |
224 | <!-- INDENTATION --> | |
225 | <p><b>No space for strip buffer</b>. There was insufficient | |
226 | memory to allocate an i/o buffer.</p> | |
227 | <!-- INDENTATION --> | |
228 | <p><b>Can not handle format</b>. The image has a format | |
229 | (combination of <i>BitsPerSample</i>, | |
230 | <i>SamplesPerPixel</i>, and | |
231 | <i>PhotometricInterpretation</i>) that | |
232 | <i>TIFFReadRGBAImage</i> can not handle.</p> | |
233 | <!-- INDENTATION --> | |
234 | <p><b>No space for B&W mapping table</b>. There was | |
235 | insufficient memory to allocate a table used to map | |
236 | grayscale data to <small>RGB.</small></p> | |
237 | <!-- INDENTATION --> | |
238 | <p><b>No space for Palette mapping table</b>. There was | |
239 | insufficient memory to allocate a table used to map data to | |
240 | 8-bit <small>RGB.</small></p> | |
241 | </td> | |
242 | </table> | |
243 | <a name="SEE ALSO"></a> | |
244 | <h2>SEE ALSO</h2> | |
245 | <!-- INDENTATION --> | |
246 | <table width="100%" border=0 rules="none" frame="void" | |
247 | cols="2" cellspacing="0" cellpadding="0"> | |
248 | <tr valign="top" align="left"> | |
249 | <td width="8%"></td> | |
250 | <td width="91%"> | |
251 | <p><b>TIFFOpen</b>(3TIFF), <b>TIFFRGBAImage</b>(3TIFF), | |
252 | <b>TIFFReadRGBAImage</b>(3TIFF), | |
253 | <b>TIFFReadRGBAStrip</b>(3TIFF), <b>libtiff</b>(3TIFF)</p> | |
254 | <!-- INDENTATION --> | |
255 | <p>Libtiff library home page: | |
256 | <b>http://www.remotesensing.org/libtiff/</b></p> | |
257 | </td> | |
258 | </table> | |
259 | <hr> | |
260 | </body> | |
261 | </html> |