libtiff/html/man/TIFFReadRGBAImage.3t.html
2003-12-21 21:47:11 +00:00

341 lines
13 KiB
HTML

<html>
<head>
<meta name="generator" content="groff -Thtml, see www.gnu.org">
<meta name="Content-Style" content="text/css">
<title>TIFFReadRGBAImage</title>
</head>
<body>
<h1 align=center>TIFFReadRGBAImage</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#NOTES">NOTES</a><br>
<a href="#RETURN VALUES">RETURN VALUES</a><br>
<a href="#DIAGNOSTICS">DIAGNOSTICS</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<hr>
<!-- Creator : groff version 1.17.2 -->
<!-- CreationDate: Mon Dec 22 00:39:24 2003 -->
<a name="NAME"></a>
<h2>NAME</h2>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
TIFFReadRGBAImage - read and decode an image into a fixed-format raster</td></table>
<a name="SYNOPSIS"></a>
<h2>SYNOPSIS</h2>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>#include &lt;tiffio.h&gt;</b></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>#define TIFFGetR(abgr) ((abgr) &amp; 0xff)<br>
#define TIFFGetG(abgr) (((abgr) &gt;&gt; 8) &amp; 0xff)<br>
#define TIFFGetB(abgr) (((abgr) &gt;&gt; 16) &amp; 0xff)<br>
#define TIFFGetA(abgr) (((abgr) &gt;&gt; 24) &amp;
0xff)</b></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>int TIFFReadRGBAImage(TIFF *</b><i>tif</i><b>, u_long</b>
<i>width</i><b>, u_long</b> <i>height</i><b>, u_long
*</b><i>raster</i><b>, int</b> <i>stopOnError</i><b>)<br>
int TIFFReadRGBAImageOriented(TIFF *</b><i>tif</i><b>,
u_long</b> <i>width</i><b>, u_long</b> <i>height</i><b>,
u_long *</b><i>raster</i><b>, int</b> <i>orientation</i><b>,
int</b> <i>stopOnError</i><b>)</b></td></table>
<a name="DESCRIPTION"></a>
<h2>DESCRIPTION</h2>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<i>TIFFReadRGBAImage</i> reads a strip- or tile-based image
into memory, storing the result in the user supplied
<i>raster</i>. The raster is assumed to be an array of
<i>width</i> times <i>height</i> 32-bit entries, where
<i>width</i> must be less than or equal to the width of the
image (<i>height</i> may be any non-zero size). If the
raster dimensions are smaller than the image, the image data
is cropped to the raster bounds. If the raster height is
greater than that of the image, then the image data are
placed in the lower part of the raster. (Note that the
raster is assume to be organized such that the pixel at
location (<i>x</i>,<i>y</i>) is
<i>raster</i>[<i>y</i>*<i>width</i>+<i>x</i>]; with the
raster origin in the lower-left hand corner.)</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<i>TIFFReadRGBAImageOriented</i> works like
<i>TIFFReadRGBAImage</i> with except of that user can
specify the raster origin position with the
<i>orientation</i> parameter. Four orientations
supported:</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>ORIENTATION_TOPLEFT</b></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="21%"></td><td width="79%">
origin in top-left corner,</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>ORIENTATION_TOPRIGHT</b></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="21%"></td><td width="79%">
origin in top-right corner,</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>ORIENTATION_BOTLEFT</b></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="21%"></td><td width="79%">
origin in bottom-left corner and</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>ORIENTATION_BOTRIGHT</b></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="21%"></td><td width="79%">
origin in bottom-right corner.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
If you choose <b>ORIENTATION_BOTLEFT</b> result will be the
same as returned by the
<i>TIFFReadRGBAImage.</i></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
Raster pixels are 8-bit packed red, green, blue, alpha
samples. The macros <i>TIFFGetR</i>, <i>TIFFGetG</i>,
<i>TIFFGetB</i>, and <i>TIFFGetA</i> should be used to
access individual samples. Images without Associated Alpha
matting information have a constant Alpha of 1.0
(255).</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<i>TIFFReadRGBAImage</i> converts non-8-bit images by
scaling sample values. Palette, grayscale, bilevel,
<small>CMYK</small> , and YCbCr images are converted to
<small>RGB</small> transparently. Raster pixels are returned
uncorrected by any colorimetry information present in the
directory.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
The paramater <i>stopOnError</i> specifies how to act if an
error is encountered while reading the image. If
<i>stopOnError</i> is non-zero, then an error will terminate
the operation; otherwise <i>TIFFReadRGBAImage</i> will
continue processing data until all the possible data in the
image have been requested.</td></table>
<a name="NOTES"></a>
<h2>NOTES</h2>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
In C++ the <i>stopOnError</i> parameter defaults to
0.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
Samples must be either 1, 2, 4, 8, or 16 bits. Colorimetric
samples/pixel must be either 1, 3, or 4 (i.e.
<i>SamplesPerPixel</i> minus
<i>ExtraSamples</i>).</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
Palettte image colormaps that appear to be incorrectly
written as 8-bit values are automatically scaled to
16-bits.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<i>TIFFReadRGBAImage</i> is just a wrapper around the more
general <i>TIFFRGBAImage</i>(3T) facilities.</td></table>
<a name="RETURN VALUES"></a>
<h2>RETURN VALUES</h2>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
1 is returned if the image was successfully read and
converted. Otherwise, 0 is returned if an error was
encountered and <i>stopOnError</i> is zero.</td></table>
<a name="DIAGNOSTICS"></a>
<h2>DIAGNOSTICS</h2>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
All error messages are directed to the <i>TIFFError</i>(3T)
routine.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>Sorry, can not handle %d-bit pictures</b>. The image had
<i>BitsPerSample</i> other than 1, 2, 4, 8, or
16.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>Sorry, can not handle %d-channel images</b>. The image
had <i>SamplesPerPixel</i> other than 1, 3, or
4.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>Missing needed &quot;PhotometricInterpretation&quot;
tag</b>. The image did not have a tag that describes how to
display the data.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>No &quot;PhotometricInterpretation&quot; tag, assuming
RGB</b>. The image was missing a tag that describes how to
display it, but because it has 3 or 4 samples/pixel, it is
assumed to be <small>RGB.</small></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>No &quot;PhotometricInterpretation&quot; tag, assuming
min-is-black</b>. The image was missing a tag that describes
how to display it, but because it has 1 sample/pixel, it is
assumed to be a grayscale or bilevel image.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>No space for photometric conversion table</b>. There was
insufficient memory for a table used to convert image
samples to 8-bit <small>RGB.</small></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>Missing required &quot;Colormap&quot; tag</b>. A Palette
image did not have a required <i>Colormap</i>
tag.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>No space for tile buffer</b>. There was insufficient
memory to allocate an i/o buffer.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>No space for strip buffer</b>. There was insufficient
memory to allocate an i/o buffer.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>Can not handle format</b>. The image has a format
(combination of <i>BitsPerSample</i>,
<i>SamplesPerPixel</i>, and
<i>PhotometricInterpretation</i>) that
<i>TIFFReadRGBAImage</i> can not handle.</td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>No space for B&amp;W mapping table</b>. There was
insufficient memory to allocate a table used to map
grayscale data to <small>RGB.</small></td></table>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<b>No space for Palette mapping table</b>. There was
insufficient memory to allocate a table used to map data to
8-bit <small>RGB.</small></td></table>
<a name="SEE ALSO"></a>
<h2>SEE ALSO</h2>
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="10%"></td><td width="90%">
<i>libtiff</i>(3T), <i>TIFFOpen</i>(3T),
<i>TIFFRGBAImage</i>(3T), <i>TIFFReadRGBAStrip</i>(3T),
<i>TIFFReadRGBATile</i>(3T)</td></table>
<hr>
</body>
</html>