1<!-- Creator : groff version 1.19.2 --> 2<!-- CreationDate: Mon Jan 2 17:41:39 2006 --> 3<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 4"http://www.w3.org/TR/html4/loose.dtd"> 5<html> 6<head> 7<meta name="generator" content="groff -Thtml, see www.gnu.org"> 8<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> 9<meta name="Content-Style" content="text/css"> 10<style type="text/css"> 11 p { margin-top: 0; margin-bottom: 0; } 12 pre { margin-top: 0; margin-bottom: 0; } 13 table { margin-top: 0; margin-bottom: 0; } 14</style> 15<title>TIFFReadDirectory</title> 16 17</head> 18<body> 19 20<h1 align=center>TIFFReadDirectory</h1> 21 22<a href="#NAME">NAME</a><br> 23<a href="#SYNOPSIS">SYNOPSIS</a><br> 24<a href="#DESCRIPTION">DESCRIPTION</a><br> 25<a href="#NOTES">NOTES</a><br> 26<a href="#RETURN VALUES">RETURN VALUES</a><br> 27<a href="#DIAGNOSTICS">DIAGNOSTICS</a><br> 28<a href="#SEE ALSO">SEE ALSO</a><br> 29 30<hr> 31 32 33<a name="NAME"></a> 34<h2>NAME</h2> 35 36 37 38<p style="margin-left:11%; margin-top: 1em">TIFFReadDirectory 39− get the contents of the next directory in an open 40<small>TIFF</small> file</p> 41 42<a name="SYNOPSIS"></a> 43<h2>SYNOPSIS</h2> 44 45 46<p style="margin-left:11%; margin-top: 1em"><b>#include 47<tiffio.h></b></p> 48 49<p style="margin-left:11%; margin-top: 1em"><b>int 50TIFFReadDirectory(TIFF *</b><i>tif</i><b>)</b></p> 51 52<a name="DESCRIPTION"></a> 53<h2>DESCRIPTION</h2> 54 55 56<p style="margin-left:11%; margin-top: 1em">Read the next 57directory in the specified file and make it the current 58directory. Applications only need to call 59<i>TIFFReadDirectory</i> to read multiple subfiles in a 60single <small>TIFF</small> file— the first directory 61in a file is automatically read when <i>TIFFOpen</i> is 62called.</p> 63 64<a name="NOTES"></a> 65<h2>NOTES</h2> 66 67 68<p style="margin-left:11%; margin-top: 1em">If the library 69is compiled with <small>STRIPCHOP_SUPPORT</small> enabled, 70then images that have a single uncompressed strip or tile of 71data are automatically treated as if they were made up of 72multiple strips or tiles of approximately 8 kilobytes each. 73This operation is done only in-memory; it does not alter the 74contents of the file. However, the construction of the 75‘‘chopped strips’’ is visible to the 76application through the number of strips [tiles] returned by 77<i>TIFFNumberOfStrips</i> [<i>TIFFNumberOfTiles</i>].</p> 78 79<a name="RETURN VALUES"></a> 80<h2>RETURN VALUES</h2> 81 82 83<p style="margin-left:11%; margin-top: 1em">If the next 84directory was successfully read, 1 is returned. Otherwise, 0 85is returned if an error was encountered, or if there are no 86more directories to be read.</p> 87 88<a name="DIAGNOSTICS"></a> 89<h2>DIAGNOSTICS</h2> 90 91 92<p style="margin-left:11%; margin-top: 1em">All error 93messages are directed to the <i>TIFFError</i>(3TIFF) 94routine. All warning messages are directed to the 95<i>TIFFWarning</i>(3TIFF) routine.</p> 96 97<p style="margin-left:11%; margin-top: 1em"><b>Seek error 98accessing TIFF directory</b>. An error occurred while 99positioning to the location of the directory.</p> 100 101<p style="margin-left:11%; margin-top: 1em"><b>Wrong data 102type %d for field "%s"</b>. The tag entry in the 103directory had an incorrect data type. For example, an 104<i>ImageDescription</i> tag with a <small>SHORT</small> data 105type.</p> 106 107<p style="margin-left:11%; margin-top: 1em"><b>TIFF 108directory is missing required "%s" field</b>. The 109specified tag is required to be present by the 110<small>TIFF</small> 5.0 specification, but is missing. The 111directory is (usually) unusable.</p> 112 113<p style="margin-left:11%; margin-top: 1em"><b>%s: Rational 114with zero denominator</b>. A directory tag has a 115<small>RATIONAL</small> value whose denominator is zero.</p> 116 117<p style="margin-left:11%; margin-top: 1em"><b>Incorrect 118count %d for field "%s" (%lu, expecting %lu); tag 119ignored</b>. The specified tag’s count field is bad. 120For example, a count other than 1 for a <i>SubFileType</i> 121tag.</p> 122 123<p style="margin-left:11%; margin-top: 1em"><b>Cannot 124handle different per-sample values for field 125"%s"</b>. The tag has <i>SamplesPerPixel</i> 126values and they are not all the same; e.g. 127<i>BitsPerSample</i>. The library is unable to handle images 128of this sort.</p> 129 130<p style="margin-left:11%; margin-top: 1em"><b>Count 131mismatch for field "%s"; expecting %d, got %d</b>. 132The count field in a tag does not agree with the number 133expected by the library. This should never happen, so if it 134does, the library refuses to read the directory.</p> 135 136<p style="margin-left:11%; margin-top: 1em"><b>Invalid TIFF 137directory; tags are not sorted in ascending order</b>. The 138directory tags are not properly sorted as specified in the 139<small>TIFF</small> 5.0 specification. This error is not 140fatal.</p> 141 142<p style="margin-left:11%; margin-top: 1em"><b>Ignoring 143unknown field with tag %d (0x%x)</b>. An unknown tag was 144encountered in the directory; the library ignores all such 145tags.</p> 146 147<p style="margin-left:11%; margin-top: 1em"><b>TIFF 148directory is missing requred "ImageLength" 149field</b>. The image violates the specification by not 150having a necessary field. There is no way for the library to 151recover from this error.</p> 152 153<p style="margin-left:11%; margin-top: 1em"><b>TIFF 154directory is missing requred "PlanarConfig" 155field</b>. The image violates the specification by not 156having a necessary field. There is no way for the library to 157recover from this error.</p> 158 159<p style="margin-left:11%; margin-top: 1em"><b>TIFF 160directory is missing requred "StripOffsets" 161field</b>. The image has multiple strips, but is missing the 162tag that specifies the file offset to each strip of data. 163There is no way for the library to recover from this 164error.</p> 165 166<p style="margin-left:11%; margin-top: 1em"><b>TIFF 167directory is missing requred "TileOffsets" 168field</b>. The image has multiple tiles, but is missing the 169tag that specifies the file offset to each tile of data. 170There is no way for the library to recover from this 171error.</p> 172 173<p style="margin-left:11%; margin-top: 1em"><b>TIFF 174directory is missing required "StripByteCounts" 175field</b>. The image has multiple strips, but is missing the 176tag that specifies the size of each strip of data. There is 177no way for the library to recover from this error.</p> 178 179<p style="margin-left:11%; margin-top: 1em"><b>TIFF 180directory is missing required "StripByteCounts" 181field, calculating from imagelength</b>. The image violates 182the specification by not having a necessary field. However, 183when the image is comprised of only one strip or tile, the 184library will estimate the missing value based on the file 185size.</p> 186 187<p style="margin-left:11%; margin-top: 1em"><b>Bogus 188"StripByteCounts" field, ignoring and calculating 189from imagelength</b>. Certain vendors violate the 190specification by writing zero for the StripByteCounts tag 191when they want to leave the value unspecified. If the image 192has a single strip, the library will estimate the missing 193value based on the file size.</p> 194 195<a name="SEE ALSO"></a> 196<h2>SEE ALSO</h2> 197 198 199 200<p style="margin-left:11%; margin-top: 1em"><b>TIFFOpen</b>(3TIFF), 201<b>TIFFWriteDirectory</b>(3TIFF), 202<b>TIFFSetDirectory</b>(3TIFF), 203<b>TIFFSetSubDirectory</b>(3TIFF), <b>libtiff</b>(3TIFF)</p> 204 205<p style="margin-left:11%; margin-top: 1em">Libtiff library 206home page: <b>http://www.remotesensing.org/libtiff/</b></p> 207<hr> 208</body> 209</html> 210