src/tiff/html/man/TIFFReadRGBAStrip.3tiff.html

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   7 <title>TIFFReadRGBAStrip</title>
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  10
  11 <h1 align=center>TIFFReadRGBAStrip</h1>
  12 <a href="#NAME">NAME</a><br>
  13 <a href="#SYNOPSIS">SYNOPSIS</a><br>
  14 <a href="#DESCRIPTION">DESCRIPTION</a><br>
  15 <a href="#NOTES">NOTES</a><br>
  16 <a href="#RETURN VALUES">RETURN VALUES</a><br>
  17 <a href="#DIAGNOSTICS">DIAGNOSTICS</a><br>
  18 <a href="#SEE ALSO">SEE ALSO</a><br>
  19
  20 <hr>
  21 <a name="NAME"></a>
  22 <h2>NAME</h2>
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  29 <p>TIFFReadRGBAStrip &minus; read and decode an image strip
  30 into a fixed-format raster</p>
  31 </td>
  32 </table>
  33 <a name="SYNOPSIS"></a>
  34 <h2>SYNOPSIS</h2>
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  41 <p><b>#include &lt;tiffio.h&gt;</b></p>
  42 <!-- INDENTATION -->
  43 <p><b>#define TIFFGetR(abgr) ((abgr) &amp; 0xff)<br>
  44 #define TIFFGetG(abgr) (((abgr) &gt;&gt; 8) &amp; 0xff)<br>
  45 #define TIFFGetB(abgr) (((abgr) &gt;&gt; 16) &amp; 0xff)<br>
  46 #define TIFFGetA(abgr) (((abgr) &gt;&gt; 24) &amp;
  47 0xff)</b></p>
  48 <!-- INDENTATION -->
  49 <p><b>int TIFFReadRGBAStrip(TIFF *</b><i>tif</i><b>,
  50 uint32</b> <i>row</i><b>, uint32
  51 *</b><i>raster</i><b>)</b></p>
  52 </td>
  53 </table>
  54 <a name="DESCRIPTION"></a>
  55 <h2>DESCRIPTION</h2>
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  62 <p><i>TIFFReadRGBAStrip</i> reads a single strip of a
  63 strip-based image into memory, storing the result in the
  64 user supplied RGBA <i>raster</i>. The raster is assumed to
  65 be an array of width times rowsperstrip 32-bit entries,
  66 where width is the width of the image (TIFFTAG_IMAGEWIDTH)
  67 and rowsperstrip is the maximum lines in a strip
  68 (TIFFTAG_ROWSPERSTRIP).</p>
  69 <!-- INDENTATION -->
  70 <p>The <i>row</i> value should be the row of the first row
  71 in the strip (strip * rowsperstrip, zero based).</p>
  72 <!-- INDENTATION -->
  73 <p>Note that the raster is assume to be organized such that
  74 the pixel at location (<i>x</i>,<i>y</i>) is
  75 <i>raster</i>[<i>y</i>*<i>width</i>+<i>x</i>]; with the
  76 raster origin in the <i>lower-left hand corner</i> of the
  77 strip. That is bottom to top organization. When reading a
  78 partial last strip in the file the last line of the image
  79 will begin at the beginning of the buffer.</p>
  80 <!-- INDENTATION -->
  81 <p>Raster pixels are 8-bit packed red, green, blue, alpha
  82 samples. The macros <i>TIFFGetR</i>, <i>TIFFGetG</i>,
  83 <i>TIFFGetB</i>, and <i>TIFFGetA</i> should be used to
  84 access individual samples. Images without Associated Alpha
  85 matting information have a constant Alpha of 1.0 (255).</p>
  86 <!-- INDENTATION -->
  87 <p>See the <i>TIFFRGBAImage</i>(3TIFF) page for more details
  88 on how various image types are converted to RGBA values.</p>
  89 </td>
  90 </table>
  91 <a name="NOTES"></a>
  92 <h2>NOTES</h2>
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  99 <p>Samples must be either 1, 2, 4, 8, or 16 bits.
 100 Colorimetric samples/pixel must be either 1, 3, or 4 (i.e.
 101 <i>SamplesPerPixel</i> minus <i>ExtraSamples</i>).</p>
 102 <!-- INDENTATION -->
 103 <p>Palette image colormaps that appear to be incorrectly
 104 written as 8-bit values are automatically scaled to
 105 16-bits.</p>
 106 <!-- INDENTATION -->
 107 <p><i>TIFFReadRGBAStrip</i> is just a wrapper around the
 108 more general <i>TIFFRGBAImage</i>(3TIFF) facilities.
 109 It&rsquo;s main advantage over the similar
 110 <i>TIFFReadRGBAImage()</i> function is that for large images
 111 a single buffer capable of holding the whole image
 112 doesn&rsquo;t need to be allocated, only enough for one
 113 strip. The <i>TIFFReadRGBATile()</i> function does a similar
 114 operation for tiled images.</p>
 115 </td>
 116 </table>
 117 <a name="RETURN VALUES"></a>
 118 <h2>RETURN VALUES</h2>
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 125 <p>1 is returned if the image was successfully read and
 126 converted. Otherwise, 0 is returned if an error was
 127 encountered.</p>
 128 </td>
 129 </table>
 130 <a name="DIAGNOSTICS"></a>
 131 <h2>DIAGNOSTICS</h2>
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 138 <p>All error messages are directed to the
 139 <i>TIFFError</i>(3TIFF) routine.</p>
 140 <!-- INDENTATION -->
 141 <p><b>Sorry, can not handle %d-bit pictures</b>. The image
 142 had <i>BitsPerSample</i> other than 1, 2, 4, 8, or 16.</p>
 143 <!-- INDENTATION -->
 144 <p><b>Sorry, can not handle %d-channel images</b>. The image
 145 had <i>SamplesPerPixel</i> other than 1, 3, or 4.</p>
 146 <!-- INDENTATION -->
 147 <p><b>Missing needed &quot;PhotometricInterpretation&quot;
 148 tag</b>. The image did not have a tag that describes how to
 149 display the data.</p>
 150 <!-- INDENTATION -->
 151 <p><b>No &quot;PhotometricInterpretation&quot; tag, assuming
 152 RGB</b>. The image was missing a tag that describes how to
 153 display it, but because it has 3 or 4 samples/pixel, it is
 154 assumed to be <small>RGB.</small></p>
 155 <!-- INDENTATION -->
 156 <p><b>No &quot;PhotometricInterpretation&quot; tag, assuming
 157 min-is-black</b>. The image was missing a tag that describes
 158 how to display it, but because it has 1 sample/pixel, it is
 159 assumed to be a grayscale or bilevel image.</p>
 160 <!-- INDENTATION -->
 161 <p><b>No space for photometric conversion table</b>. There
 162 was insufficient memory for a table used to convert image
 163 samples to 8-bit <small>RGB.</small></p>
 164 <!-- INDENTATION -->
 165 <p><b>Missing required &quot;Colormap&quot; tag</b>. A
 166 Palette image did not have a required <i>Colormap</i>
 167 tag.</p>
 168 <!-- INDENTATION -->
 169 <p><b>No space for tile buffer</b>. There was insufficient
 170 memory to allocate an i/o buffer.</p>
 171 <!-- INDENTATION -->
 172 <p><b>No space for strip buffer</b>. There was insufficient
 173 memory to allocate an i/o buffer.</p>
 174 <!-- INDENTATION -->
 175 <p><b>Can not handle format</b>. The image has a format
 176 (combination of <i>BitsPerSample</i>,
 177 <i>SamplesPerPixel</i>, and
 178 <i>PhotometricInterpretation</i>) that
 179 <i>TIFFReadRGBAImage</i> can not handle.</p>
 180 <!-- INDENTATION -->
 181 <p><b>No space for B&amp;W mapping table</b>. There was
 182 insufficient memory to allocate a table used to map
 183 grayscale data to <small>RGB.</small></p>
 184 <!-- INDENTATION -->
 185 <p><b>No space for Palette mapping table</b>. There was
 186 insufficient memory to allocate a table used to map data to
 187 8-bit <small>RGB.</small></p>
 188 </td>
 189 </table>
 190 <a name="SEE ALSO"></a>
 191 <h2>SEE ALSO</h2>
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 198 <p><b>TIFFOpen</b>(3TIFF), <b>TIFFRGBAImage</b>(3TIFF),
 199 <b>TIFFReadRGBAImage</b>(3TIFF),
 200 <b>TIFFReadRGBATile</b>(3TIFF), <b>libtiff</b>(3TIFF)</p>
 201 <!-- INDENTATION -->
 202 <p>Libtiff library home page:
 203 <b>http://www.remotesensing.org/libtiff/</b></p>
 204 </td>
 205 </table>
 206 <hr>
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