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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> |
| <a name="NAME"></a> |
| <h2>NAME</h2> |
| |
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| <td width="91%"> |
| <p>TIFFReadRGBAStrip − read and decode an image strip |
| into a fixed-format raster</p> |
| </td> |
| </table> |
| <a name="SYNOPSIS"></a> |
| <h2>SYNOPSIS</h2> |
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| <p><b>#include <tiffio.h></b></p> |
| |
| <p><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><b>int TIFFReadRGBAStrip(TIFF *</b><i>tif</i><b>, |
| uint32</b> <i>row</i><b>, uint32 |
| *</b><i>raster</i><b>)</b></p> |
| </td> |
| </table> |
| <a name="DESCRIPTION"></a> |
| <h2>DESCRIPTION</h2> |
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| <p><i>TIFFReadRGBAStrip</i> 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>The <i>row</i> value should be the row of the first row |
| in the strip (strip * rowsperstrip, zero based).</p> |
| |
| <p>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>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>See the <i>TIFFRGBAImage</i>(3TIFF) page for more details |
| on how various image types are converted to RGBA values.</p> |
| </td> |
| </table> |
| <a name="NOTES"></a> |
| <h2>NOTES</h2> |
| |
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| <p>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>Palette image colormaps that appear to be incorrectly |
| written as 8-bit values are automatically scaled to |
| 16-bits.</p> |
| |
| <p><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> |
| </td> |
| </table> |
| <a name="RETURN VALUES"></a> |
| <h2>RETURN VALUES</h2> |
| |
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| <p>1 is returned if the image was successfully read and |
| converted. Otherwise, 0 is returned if an error was |
| encountered.</p> |
| </td> |
| </table> |
| <a name="DIAGNOSTICS"></a> |
| <h2>DIAGNOSTICS</h2> |
| |
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| <p>All error messages are directed to the |
| <i>TIFFError</i>(3TIFF) routine.</p> |
| |
| <p><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><b>Sorry, can not handle %d-channel images</b>. The image |
| had <i>SamplesPerPixel</i> other than 1, 3, or 4.</p> |
| |
| <p><b>Missing needed "PhotometricInterpretation" |
| tag</b>. The image did not have a tag that describes how to |
| display the data.</p> |
| |
| <p><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><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><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><b>Missing required "Colormap" tag</b>. A |
| Palette image did not have a required <i>Colormap</i> |
| tag.</p> |
| |
| <p><b>No space for tile buffer</b>. There was insufficient |
| memory to allocate an i/o buffer.</p> |
| |
| <p><b>No space for strip buffer</b>. There was insufficient |
| memory to allocate an i/o buffer.</p> |
| |
| <p><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><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><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> |
| </td> |
| </table> |
| <a name="SEE ALSO"></a> |
| <h2>SEE ALSO</h2> |
| |
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| <p><b>TIFFOpen</b>(3TIFF), <b>TIFFRGBAImage</b>(3TIFF), |
| <b>TIFFReadRGBAImage</b>(3TIFF), |
| <b>TIFFReadRGBATile</b>(3TIFF), <b>libtiff</b>(3TIFF)</p> |
| |
| <p>Libtiff library home page: |
| <b>http://www.simplesystems.org/libtiff/</b></p> |
| </td> |
| </table> |
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