bionic (3) TIFFReadDirectory.3tiff.gz

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 automatically 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.  BitsPerSample.  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 offset 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 having 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.simplesystems.org/libtiff/