TIFFReadDirectory(3TIFF)												  TIFFReadDirectory(3TIFF)

NAME

       TIFFReadDirectory - get the contents of the next directory in an open TIFF file

SYNOPSIS

       #include <tiffio.h>

       int TIFFReadDirectory(TIFF *tif)

DESCRIPTION

       Read  the  next directory in the specified file and make it the current directory. Applications only need to call TIFFReadDirectory to read
       multiple subfiles in a single TIFF file-- the first directory in a file is automatically read when TIFFOpen is called.

NOTES

       If the library is compiled with STRIPCHOP_SUPPORT enabled, then images that have a single uncompressed strip or tile of data are  automati-
       cally treated as if they were made up of multiple strips or tiles of approximately 8 kilobytes each. This operation is done only in-memory;
       it does not alter the contents of the file. However, the construction of the ``chopped strips'' is visible to the application  through  the
       number of strips [tiles] returned by TIFFNumberOfStrips [TIFFNumberOfTiles].

RETURN VALUES

       If  the	next directory was successfully read, 1 is returned. Otherwise, 0 is returned if an error was encountered, or if there are no more
       directories to be read.

DIAGNOSTICS

       All error messages are directed to the TIFFError(3TIFF) routine.  All warning messages are directed to the TIFFWarning(3TIFF) routine.

       Seek error accessing TIFF directory.  An error occurred while positioning to the location of the directory.

       Wrong data type %d for field "%s".  The tag entry in the directory had an incorrect data type.  For example, an ImageDescription tag with a
       SHORT data type.

       TIFF  directory is missing required "%s" field.	The specified tag is required to be present by the TIFF 5.0 specification, but is missing.
       The directory is (usually) unusable.

       %s: Rational with zero denominator.  A directory tag has a RATIONAL value whose denominator is zero.

       Incorrect count %d for field "%s" (%lu, expecting %lu); tag ignored.  The specified tag's count field is bad.  For example, a  count  other
       than 1 for a SubFileType tag.

       Cannot handle different per-sample values for field "%s".  The tag has SamplesPerPixel values and they are not all the same; e.g.  BitsPer-
       Sample.	The library is unable to handle images of this sort.

       Count mismatch for field "%s"; expecting %d, got %d.  The count field in a tag does not agree with the  number  expected  by  the  library.
       This should never happen, so if it does, the library refuses to read the directory.

       Invalid	TIFF  directory;  tags are not sorted in ascending order.  The directory tags are not properly sorted as specified in the TIFF 5.0
       specification.  This error is not fatal.

       Ignoring unknown field with tag %d (0x%x).  An unknown tag was encountered in the directory; the library ignores all such tags.

       TIFF directory is missing required "ImageLength" field.	The image violates the specification by not having a necessary field.  There is no
       way for the library to recover from this error.

       TIFF  directory	is missing required "PlanarConfig" field.  The image violates the specification by not having a necessary field.  There is
       no way for the library to recover from this error.

       TIFF directory is missing required "StripOffsets" field.  The image has multiple strips, but is missing the tag	that  specifies  the  file
       offset to each strip of data.  There is no way for the library to recover from this error.

       TIFF  directory is missing required "TileOffsets" field.  The image has multiple tiles, but is missing the tag that specifies the file off-
       set to each tile of data.  There is no way for the library to recover from this error.

       TIFF directory is missing required "StripByteCounts" field.  The image has multiple strips, but is missing the tag that specifies the  size
       of each strip of data.  There is no way for the library to recover from this error.

       TIFF directory is missing required "StripByteCounts" field, calculating from imagelength.  The image violates the specification by not hav-
       ing a necessary field.  However, when the image is comprised of only one strip or tile, the library will estimate the missing  value  based
       on the file size.

       Bogus  "StripByteCounts"  field,  ignoring and calculating from imagelength.  Certain vendors violate the specification by writing zero for
       the StripByteCounts tag when they want to leave the value unspecified.  If the image has a single strip,  the  library  will  estimate  the
       missing value based on the file size.

SEE ALSO

       TIFFOpen(3TIFF), TIFFWriteDirectory(3TIFF), TIFFSetDirectory(3TIFF), TIFFSetSubDirectory(3TIFF), libtiff(3TIFF)

       Libtiff library home page: http://www.remotesensing.org/libtiff/

libtiff 							 October 15, 1995					  TIFFReadDirectory(3TIFF)