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1 | .\" $Id: TIFFReadRGBAImage.3tiff,v 1.3 2005/11/02 11:07:18 dron Exp $ |
2 | .\" | |
3 | .\" Copyright (c) 1991-1997 Sam Leffler | |
4 | .\" Copyright (c) 1991-1997 Silicon Graphics, Inc. | |
5 | .\" | |
6 | .\" Permission to use, copy, modify, distribute, and sell this software and | |
7 | .\" its documentation for any purpose is hereby granted without fee, provided | |
8 | .\" that (i) the above copyright notices and this permission notice appear in | |
9 | .\" all copies of the software and related documentation, and (ii) the names of | |
10 | .\" Sam Leffler and Silicon Graphics may not be used in any advertising or | |
11 | .\" publicity relating to the software without the specific, prior written | |
12 | .\" permission of Sam Leffler and Silicon Graphics. | |
13 | .\" | |
14 | .\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, | |
15 | .\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY | |
16 | .\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. | |
17 | .\" | |
18 | .\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR | |
19 | .\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, | |
20 | .\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, | |
21 | .\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF | |
22 | .\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE | |
23 | .\" OF THIS SOFTWARE. | |
24 | .\" | |
25 | .if n .po 0 | |
26 | .TH TIFFReadRGBAImage 3TIFF "October 29, 2004" "libtiff" | |
27 | .SH NAME | |
28 | TIFFReadRGBAImage, TIFFReadRGBAImageOriented \- read and decode an image | |
29 | into a fixed-format raster | |
30 | .SH SYNOPSIS | |
31 | .B "#include <tiffio.h>" | |
32 | .sp | |
33 | .B "#define TIFFGetR(abgr) ((abgr) & 0xff)" | |
34 | .br | |
35 | .B "#define TIFFGetG(abgr) (((abgr) >> 8) & 0xff)" | |
36 | .br | |
37 | .B "#define TIFFGetB(abgr) (((abgr) >> 16) & 0xff)" | |
38 | .br | |
39 | .B "#define TIFFGetA(abgr) (((abgr) >> 24) & 0xff)" | |
40 | .sp | |
41 | .BI "int TIFFReadRGBAImage(TIFF *" tif ", u_long " width ", u_long " height ", u_long *" raster ", int " stopOnError ")" | |
42 | .br | |
43 | .BI "int TIFFReadRGBAImageOriented(TIFF *" tif ", u_long " width ", u_long " height ", u_long *" raster ", int " orientation ", int " stopOnError ")" | |
44 | .br | |
45 | .SH DESCRIPTION | |
46 | .IR TIFFReadRGBAImage | |
47 | reads a strip- or tile-based image into memory, storing the | |
48 | result in the user supplied | |
49 | .IR raster . | |
50 | The raster is assumed to be an array of | |
51 | .I width | |
52 | times | |
53 | .I height | |
54 | 32-bit entries, where | |
55 | .I width | |
56 | must be less than or equal to the width of the image (\c | |
57 | .I height | |
58 | may be any non-zero size). | |
59 | If the raster dimensions are smaller than the image, the image data | |
60 | is cropped to the raster bounds. | |
61 | If the raster height is greater than that of the image, then the | |
62 | image data are placed in the lower part of the raster. | |
63 | (Note that the raster is assume to be organized such that the pixel | |
64 | at location (\fIx\fP,\fIy\fP) is \fIraster\fP[\fIy\fP*\fIwidth\fP+\fIx\fP]; | |
65 | with the raster origin in the lower-left hand corner.) | |
66 | .PP | |
67 | .IR TIFFReadRGBAImageOriented | |
68 | works like | |
69 | .IR TIFFReadRGBAImage | |
70 | with except of that user can specify the raster origin position with the | |
71 | .I orientation | |
72 | parameter. Four orientations supported: | |
73 | .TP | |
74 | .B ORIENTATION_TOPLEFT | |
75 | origin in top-left corner, | |
76 | .TP | |
77 | .B ORIENTATION_TOPRIGHT | |
78 | origin in top-right corner, | |
79 | .TP | |
80 | .B ORIENTATION_BOTLEFT | |
81 | origin in bottom-left corner | |
82 | and | |
83 | .TP | |
84 | .B ORIENTATION_BOTRIGHT | |
85 | origin in bottom-right corner. | |
86 | .LP | |
87 | If you choose | |
88 | .B ORIENTATION_BOTLEFT | |
89 | result will be the same as returned by the | |
90 | .IR TIFFReadRGBAImage. | |
91 | .PP | |
92 | Raster pixels are 8-bit packed red, green, blue, alpha samples. | |
93 | The macros | |
94 | .IR TIFFGetR , | |
95 | .IR TIFFGetG , | |
96 | .IR TIFFGetB , | |
97 | and | |
98 | .I TIFFGetA | |
99 | should be used to access individual samples. | |
100 | Images without Associated Alpha matting information have a constant | |
101 | Alpha of 1.0 (255). | |
102 | .PP | |
103 | .I TIFFReadRGBAImage | |
104 | converts non-8-bit images by scaling sample values. | |
105 | Palette, grayscale, bilevel, | |
106 | .SM CMYK\c | |
107 | , and YCbCr images are converted to | |
108 | .SM RGB | |
109 | transparently. | |
110 | Raster pixels are returned uncorrected by any colorimetry information | |
111 | present in the directory. | |
112 | .PP | |
113 | The paramater | |
114 | .I stopOnError | |
115 | specifies how to act if an error is encountered while reading | |
116 | the image. | |
117 | If | |
118 | .I stopOnError | |
119 | is non-zero, then an error will terminate the operation; otherwise | |
120 | .I TIFFReadRGBAImage | |
121 | will continue processing data until all the possible data in the | |
122 | image have been requested. | |
123 | .SH NOTES | |
124 | In C++ the | |
125 | .I stopOnError | |
126 | parameter defaults to 0. | |
127 | .PP | |
128 | Samples must be either 1, 2, 4, 8, or 16 bits. | |
129 | Colorimetric samples/pixel must be either 1, 3, or 4 (i.e. | |
130 | .I SamplesPerPixel | |
131 | minus | |
132 | .IR ExtraSamples ). | |
133 | .PP | |
134 | Palettte image colormaps that appear to be incorrectly written | |
135 | as 8-bit values are automatically scaled to 16-bits. | |
136 | .PP | |
137 | .I TIFFReadRGBAImage | |
138 | is just a wrapper around the more general | |
139 | .IR TIFFRGBAImage (3TIFF) | |
140 | facilities. | |
141 | .SH "RETURN VALUES" | |
142 | 1 is returned if the image was successfully read and converted. | |
143 | Otherwise, 0 is returned if an error was encountered and | |
144 | .I stopOnError | |
145 | is zero. | |
146 | .SH DIAGNOSTICS | |
147 | All error messages are directed to the | |
148 | .IR TIFFError (3TIFF) | |
149 | routine. | |
150 | .PP | |
151 | .BR "Sorry, can not handle %d-bit pictures" . | |
152 | The image had | |
153 | .I BitsPerSample | |
154 | other than 1, 2, 4, 8, or 16. | |
155 | .PP | |
156 | .BR "Sorry, can not handle %d-channel images" . | |
157 | The image had | |
158 | .I SamplesPerPixel | |
159 | other than 1, 3, or 4. | |
160 | .PP | |
161 | \fBMissing needed "PhotometricInterpretation" tag\fP. | |
162 | The image did not have a tag that describes how to display | |
163 | the data. | |
164 | .PP | |
165 | \fBNo "PhotometricInterpretation" tag, assuming RGB\fP. | |
166 | The image was missing a tag that describes how to display it, | |
167 | but because it has 3 or 4 samples/pixel, it is assumed to be | |
168 | .SM RGB. | |
169 | .PP | |
170 | \fBNo "PhotometricInterpretation" tag, assuming min-is-black\fP. | |
171 | The image was missing a tag that describes how to display it, | |
172 | but because it has 1 sample/pixel, it is assumed to be a grayscale | |
173 | or bilevel image. | |
174 | .PP | |
175 | .BR "No space for photometric conversion table" . | |
176 | There was insufficient memory for a table used to convert | |
177 | image samples to 8-bit | |
178 | .SM RGB. | |
179 | .PP | |
180 | \fBMissing required "Colormap" tag\fP. | |
181 | A Palette image did not have a required | |
182 | .I Colormap | |
183 | tag. | |
184 | .PP | |
185 | .BR "No space for tile buffer" . | |
186 | There was insufficient memory to allocate an i/o buffer. | |
187 | .PP | |
188 | .BR "No space for strip buffer" . | |
189 | There was insufficient memory to allocate an i/o buffer. | |
190 | .PP | |
191 | .BR "Can not handle format" . | |
192 | The image has a format (combination of | |
193 | .IR BitsPerSample , | |
194 | .IR SamplesPerPixel , | |
195 | and | |
196 | .IR PhotometricInterpretation ) | |
197 | that | |
198 | .I TIFFReadRGBAImage | |
199 | can not handle. | |
200 | .PP | |
201 | .BR "No space for B&W mapping table" . | |
202 | There was insufficient memory to allocate a table used to map | |
203 | grayscale data to | |
204 | .SM RGB. | |
205 | .PP | |
206 | .BR "No space for Palette mapping table" . | |
207 | There was insufficient memory to allocate a table used to map | |
208 | data to 8-bit | |
209 | .SM RGB. | |
210 | .SH "SEE ALSO" | |
211 | .BR TIFFOpen (3TIFF), | |
212 | .BR TIFFRGBAImage (3TIFF), | |
213 | .BR TIFFReadRGBAStrip (3TIFF), | |
214 | .BR TIFFReadRGBATile (3TIFF), | |
215 | .BR libtiff (3TIFF) | |
216 | .PP | |
217 | Libtiff library home page: | |
218 | .BR http://www.remotesensing.org/libtiff/ |