libtiff/html/man/TIFFReadRGBAImage.3tiff.html
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* man/{TIFFGetField.3tiff, man/TIFFSetField.3tiff}: Documented
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<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>
<a name="NAME"></a>
<h2>NAME</h2>
<p style="margin-left:11%; margin-top: 1em">TIFFReadRGBAImage,
TIFFReadRGBAImageOriented &minus; read and decode an image
into a fixed-format raster</p>
<a name="SYNOPSIS"></a>
<h2>SYNOPSIS</h2>
<p style="margin-left:11%; margin-top: 1em"><b>#include
&lt;tiffio.h&gt;</b></p>
<p style="margin-left:11%; margin-top: 1em"><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></p>
<p style="margin-left:11%; margin-top: 1em"><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></p>
<a name="DESCRIPTION"></a>
<h2>DESCRIPTION</h2>
<p style="margin-left:11%; margin-top: 1em"><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.)</p>
<p style="margin-left:11%; margin-top: 1em"><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:
<b><br>
ORIENTATION_TOPLEFT</b></p>
<p style="margin-left:22%;">origin in top-left corner,</p>
<p style="margin-left:11%;"><b>ORIENTATION_TOPRIGHT</b></p>
<p style="margin-left:22%;">origin in top-right corner,</p>
<p style="margin-left:11%;"><b>ORIENTATION_BOTLEFT</b></p>
<p style="margin-left:22%;">origin in bottom-left corner
and</p>
<p style="margin-left:11%;"><b>ORIENTATION_BOTRIGHT</b></p>
<p style="margin-left:22%;">origin in bottom-right
corner.</p>
<p style="margin-left:11%; margin-top: 1em">If you choose
<b>ORIENTATION_BOTLEFT</b> result will be the same as
returned by the <i>TIFFReadRGBAImage.</i></p>
<p style="margin-left:11%; margin-top: 1em">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).</p>
<p style="margin-left:11%; margin-top: 1em"><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.</p>
<p style="margin-left:11%; margin-top: 1em">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.</p>
<a name="NOTES"></a>
<h2>NOTES</h2>
<p style="margin-left:11%; margin-top: 1em">In C++ the
<i>stopOnError</i> parameter defaults to 0.</p>
<p style="margin-left:11%; margin-top: 1em">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>).</p>
<p style="margin-left:11%; margin-top: 1em">Palettte image
colormaps that appear to be incorrectly written as 8-bit
values are automatically scaled to 16-bits.</p>
<p style="margin-left:11%; margin-top: 1em"><i>TIFFReadRGBAImage</i>
is just a wrapper around the more general
<i>TIFFRGBAImage</i>(3TIFF) facilities.</p>
<a name="RETURN VALUES"></a>
<h2>RETURN VALUES</h2>
<p style="margin-left:11%; margin-top: 1em">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.</p>
<a name="DIAGNOSTICS"></a>
<h2>DIAGNOSTICS</h2>
<p style="margin-left:11%; margin-top: 1em">All error
messages are directed to the <i>TIFFError</i>(3TIFF)
routine.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Sorry, can
not handle %d-bit pictures</b>. The image had
<i>BitsPerSample</i> other than 1, 2, 4, 8, or 16.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Sorry, can
not handle %d-channel images</b>. The image had
<i>SamplesPerPixel</i> other than 1, 3, or 4.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Missing
needed &quot;PhotometricInterpretation&quot; tag</b>. The
image did not have a tag that describes how to display the
data.</p>
<p style="margin-left:11%; margin-top: 1em"><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></p>
<p style="margin-left:11%; margin-top: 1em"><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.</p>
<p style="margin-left:11%; margin-top: 1em"><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></p>
<p style="margin-left:11%; margin-top: 1em"><b>Missing
required &quot;Colormap&quot; tag</b>. A Palette image did
not have a required <i>Colormap</i> tag.</p>
<p style="margin-left:11%; margin-top: 1em"><b>No space for
tile buffer</b>. There was insufficient memory to allocate
an i/o buffer.</p>
<p style="margin-left:11%; margin-top: 1em"><b>No space for
strip buffer</b>. There was insufficient memory to allocate
an i/o buffer.</p>
<p style="margin-left:11%; margin-top: 1em"><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.</p>
<p style="margin-left:11%; margin-top: 1em"><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></p>
<p style="margin-left:11%; margin-top: 1em"><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></p>
<a name="SEE ALSO"></a>
<h2>SEE ALSO</h2>
<p style="margin-left:11%; margin-top: 1em"><b>TIFFOpen</b>(3TIFF),
<b>TIFFRGBAImage</b>(3TIFF),
<b>TIFFReadRGBAStrip</b>(3TIFF),
<b>TIFFReadRGBATile</b>(3TIFF), <b>libtiff</b>(3TIFF)</p>
<p style="margin-left:11%; margin-top: 1em">Libtiff library
home page: <b>http://www.remotesensing.org/libtiff/</b></p>
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