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<title>TIFFReadRGBAStrip</title>
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<h1 align="center">TIFFReadRGBAStrip</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>
<h2>NAME
<a name="NAME"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">TIFFReadRGBAStrip
− read and decode an image strip into a fixed-format
raster</p>
<h2>SYNOPSIS
<a name="SYNOPSIS"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>#include
<tiffio.h></b></p>
<p style="margin-left:11%; margin-top: 1em"><b>#define
TIFFGetR(abgr) ((abgr) & 0xff) <br>
#define TIFFGetG(abgr) (((abgr) >> 8) & 0xff) <br>
#define TIFFGetB(abgr) (((abgr) >> 16) & 0xff)
<br>
#define TIFFGetA(abgr) (((abgr) >> 24) &
0xff)</b></p>
<p style="margin-left:11%; margin-top: 1em"><b>int
TIFFReadRGBAStrip(TIFF *</b><i>tif</i><b>, uint32_t</b>
<i>row</i><b>, uint32_t *</b><i>raster</i><b>)</b></p>
<h2>DESCRIPTION
<a name="DESCRIPTION"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b><i>TIFFReadRGBAStrip</i></b>
reads a single strip of a strip-based image into memory,
storing the result in the user supplied RGBA <i>raster</i>.
The raster is assumed to be an array of width times
rowsperstrip 32-bit entries, where width is the width of the
image (TIFFTAG_IMAGEWIDTH) and rowsperstrip is the maximum
lines in a strip (TIFFTAG_ROWSPERSTRIP).</p>
<p style="margin-left:11%; margin-top: 1em">The <i>row</i>
value should be the row of the first row in the strip (strip
* rowsperstrip, zero based).</p>
<p style="margin-left:11%; margin-top: 1em">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 <i>lower-left hand corner</i> of the
strip. That is bottom to top organization. When reading a
partial last strip in the file the last line of the image
will begin at the beginning of the buffer.</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">See the
<i>TIFFRGBAImage</i>(3TIFF) page for more details on how
various image types are converted to RGBA values.</p>
<h2>NOTES
<a name="NOTES"></a>
</h2>
<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">Palette 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>TIFFReadRGBAStrip</i>
is just a wrapper around the more general
<i>TIFFRGBAImage</i>(3TIFF) facilities. It’s main
advantage over the similar <i>TIFFReadRGBAImage()</i>
function is that for large images a single buffer capable of
holding the whole image doesn’t need to be allocated,
only enough for one strip. The <i>TIFFReadRGBATile()</i>
function does a similar operation for tiled images.</p>
<h2>RETURN VALUES
<a name="RETURN VALUES"></a>
</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.</p>
<h2>DIAGNOSTICS
<a name="DIAGNOSTICS"></a>
</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 "PhotometricInterpretation" 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
"PhotometricInterpretation" 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
"PhotometricInterpretation" 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 "Colormap" 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&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>
<h2>SEE ALSO
<a name="SEE ALSO"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>TIFFOpen</b>(3TIFF),
<b>TIFFRGBAImage</b>(3TIFF),
<b>TIFFReadRGBAImage</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.simplesystems.org/libtiff/</b></p>
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