1<!-- Creator : groff version 1.18.1 --> 2<!-- CreationDate: Sat Feb 24 18:37:17 2007 --> 3<html> 4<head> 5<meta name="generator" content="groff -Thtml, see www.gnu.org"> 6<meta name="Content-Style" content="text/css"> 7<title>TIFFReadRGBAStrip</title> 8</head> 9<body> 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> 23<!-- INDENTATION --> 24<table width="100%" border=0 rules="none" frame="void" 25 cols="2" cellspacing="0" cellpadding="0"> 26<tr valign="top" align="left"> 27<td width="8%"></td> 28<td width="91%"> 29<p>TIFFReadRGBAStrip − read and decode an image strip 30into a fixed-format raster</p> 31</td> 32</table> 33<a name="SYNOPSIS"></a> 34<h2>SYNOPSIS</h2> 35<!-- INDENTATION --> 36<table width="100%" border=0 rules="none" frame="void" 37 cols="2" cellspacing="0" cellpadding="0"> 38<tr valign="top" align="left"> 39<td width="8%"></td> 40<td width="91%"> 41<p><b>#include <tiffio.h></b></p> 42<!-- INDENTATION --> 43<p><b>#define TIFFGetR(abgr) ((abgr) & 0xff)<br> 44#define TIFFGetG(abgr) (((abgr) >> 8) & 0xff)<br> 45#define TIFFGetB(abgr) (((abgr) >> 16) & 0xff)<br> 46#define TIFFGetA(abgr) (((abgr) >> 24) & 470xff)</b></p> 48<!-- INDENTATION --> 49<p><b>int TIFFReadRGBAStrip(TIFF *</b><i>tif</i><b>, 50uint32</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> 56<!-- INDENTATION --> 57<table width="100%" border=0 rules="none" frame="void" 58 cols="2" cellspacing="0" cellpadding="0"> 59<tr valign="top" align="left"> 60<td width="8%"></td> 61<td width="91%"> 62<p><i>TIFFReadRGBAStrip</i> reads a single strip of a 63strip-based image into memory, storing the result in the 64user supplied RGBA <i>raster</i>. The raster is assumed to 65be an array of width times rowsperstrip 32-bit entries, 66where width is the width of the image (TIFFTAG_IMAGEWIDTH) 67and 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 71in the strip (strip * rowsperstrip, zero based).</p> 72<!-- INDENTATION --> 73<p>Note that the raster is assume to be organized such that 74the 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 76raster origin in the <i>lower-left hand corner</i> of the 77strip. That is bottom to top organization. When reading a 78partial last strip in the file the last line of the image 79will begin at the beginning of the buffer.</p> 80<!-- INDENTATION --> 81<p>Raster pixels are 8-bit packed red, green, blue, alpha 82samples. The macros <i>TIFFGetR</i>, <i>TIFFGetG</i>, 83<i>TIFFGetB</i>, and <i>TIFFGetA</i> should be used to 84access individual samples. Images without Associated Alpha 85matting information have a constant Alpha of 1.0 (255).</p> 86<!-- INDENTATION --> 87<p>See the <i>TIFFRGBAImage</i>(3TIFF) page for more details 88on how various image types are converted to RGBA values.</p> 89</td> 90</table> 91<a name="NOTES"></a> 92<h2>NOTES</h2> 93<!-- INDENTATION --> 94<table width="100%" border=0 rules="none" frame="void" 95 cols="2" cellspacing="0" cellpadding="0"> 96<tr valign="top" align="left"> 97<td width="8%"></td> 98<td width="91%"> 99<p>Samples must be either 1, 2, 4, 8, or 16 bits. 100Colorimetric 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 104written as 8-bit values are automatically scaled to 10516-bits.</p> 106<!-- INDENTATION --> 107<p><i>TIFFReadRGBAStrip</i> is just a wrapper around the 108more general <i>TIFFRGBAImage</i>(3TIFF) facilities. 109It’s main advantage over the similar 110<i>TIFFReadRGBAImage()</i> function is that for large images 111a single buffer capable of holding the whole image 112doesn’t need to be allocated, only enough for one 113strip. The <i>TIFFReadRGBATile()</i> function does a similar 114operation for tiled images.</p> 115</td> 116</table> 117<a name="RETURN VALUES"></a> 118<h2>RETURN VALUES</h2> 119<!-- INDENTATION --> 120<table width="100%" border=0 rules="none" frame="void" 121 cols="2" cellspacing="0" cellpadding="0"> 122<tr valign="top" align="left"> 123<td width="8%"></td> 124<td width="91%"> 125<p>1 is returned if the image was successfully read and 126converted. Otherwise, 0 is returned if an error was 127encountered.</p> 128</td> 129</table> 130<a name="DIAGNOSTICS"></a> 131<h2>DIAGNOSTICS</h2> 132<!-- INDENTATION --> 133<table width="100%" border=0 rules="none" frame="void" 134 cols="2" cellspacing="0" cellpadding="0"> 135<tr valign="top" align="left"> 136<td width="8%"></td> 137<td width="91%"> 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 142had <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 145had <i>SamplesPerPixel</i> other than 1, 3, or 4.</p> 146<!-- INDENTATION --> 147<p><b>Missing needed "PhotometricInterpretation" 148tag</b>. The image did not have a tag that describes how to 149display the data.</p> 150<!-- INDENTATION --> 151<p><b>No "PhotometricInterpretation" tag, assuming 152RGB</b>. The image was missing a tag that describes how to 153display it, but because it has 3 or 4 samples/pixel, it is 154assumed to be <small>RGB.</small></p> 155<!-- INDENTATION --> 156<p><b>No "PhotometricInterpretation" tag, assuming 157min-is-black</b>. The image was missing a tag that describes 158how to display it, but because it has 1 sample/pixel, it is 159assumed to be a grayscale or bilevel image.</p> 160<!-- INDENTATION --> 161<p><b>No space for photometric conversion table</b>. There 162was insufficient memory for a table used to convert image 163samples to 8-bit <small>RGB.</small></p> 164<!-- INDENTATION --> 165<p><b>Missing required "Colormap" tag</b>. A 166Palette image did not have a required <i>Colormap</i> 167tag.</p> 168<!-- INDENTATION --> 169<p><b>No space for tile buffer</b>. There was insufficient 170memory to allocate an i/o buffer.</p> 171<!-- INDENTATION --> 172<p><b>No space for strip buffer</b>. There was insufficient 173memory 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&W mapping table</b>. There was 182insufficient memory to allocate a table used to map 183grayscale data to <small>RGB.</small></p> 184<!-- INDENTATION --> 185<p><b>No space for Palette mapping table</b>. There was 186insufficient memory to allocate a table used to map data to 1878-bit <small>RGB.</small></p> 188</td> 189</table> 190<a name="SEE ALSO"></a> 191<h2>SEE ALSO</h2> 192<!-- INDENTATION --> 193<table width="100%" border=0 rules="none" frame="void" 194 cols="2" cellspacing="0" cellpadding="0"> 195<tr valign="top" align="left"> 196<td width="8%"></td> 197<td width="91%"> 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.simplesystems.org/libtiff/</b></p> 204</td> 205</table> 206<hr> 207</body> 208</html> 209