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TIFFWriteDirectory(3TIFF) TIFFWriteDirectory(3TIFF)
NAME
TIFFWriteDirectory, TIFFRewriteDirectory, TIFFCheckpointDirectory -
write the current directory in an open TIFF file
SYNOPSIS
#include <tiffio.h>
int TIFFWriteDirectory(TIFF *tif)
int TIFFRewriteDirectory(TIFF *tif)
int TIFFCheckpointDirectory(TIFF *tif)
DESCRIPTION
TIFFWriteDirectory will write the contents of the current directory to
the file and setup to create a new subfile in the same file.
Applications only need to call TIFFWriteDirectory when writing multiple
subfiles to a single TIFF file. TIFFWriteDirectory is automatically
called by TIFFClose and TIFFFlush to write a modified directory if the
file is open for writing.
The TIFFRewriteDirectory function operates similarly to
TIFFWriteDirectory, but can be called with directories previously read
or written that already have an established location in the file. It
will rewrite the directory, but instead of place it at it's old
location (as TIFFWriteDirectory would) it will place them at the end of
the file, correcting the pointer from the preceding directory or file
header to point to it's new location. This is particularly important
in cases where the size of the directory and pointed to data has grown,
so it won't fit in the space available at the old location.
The TIFFCheckpointDirectory writes the current state of the tiff
directory into the file to make what is currently in the file readable.
Unlike TIFFWriteDirectory, TIFFCheckpointDirectory does not free up the
directory data structures in memory, so they can be updated (as
strips/tiles are written) and written again. Reading such a partial
file you will at worst get a tiff read error for the first strip/tile
encountered that is incomplete, but you will at least get all the valid
data in the file before that. When the file is complete, just use
TIFFWriteDirectory as usual to finish it off cleanly.
RETURN VALUES
1 is returned when the contents are successfully written to the file.
Otherwise, 0 is returned if an error was encountered when writing the
directory contents.
DIAGNOSTICS
All error messages are directed to the TIFFError(3TIFF) routine.
Error post-encoding before directory write. Before writing the
contents of the current directory, any pending data are flushed. This
message indicates that an error occurred while doing this.
Error flushing data before directory write. Before writing the
contents of the current directory, any pending data are flushed. This
message indicates that an error occurred while doing this.
Cannot write directory, out of space. There was not enough space to
allocate a temporary area for the directory that was to be written.
Error writing directory link. A write error occurred when writing the
link to the next directory.
Error writing data for field "%s". A write error occurred when writing
indirect data for the specified field.
Error writing TIFF header. A write error occurred when re-writing
header at the front of the file.
Error fetching directory count. A read error occurred when fetching
the directory count field for a previous directory. This can occur
when setting up a link to the directory that is being written.
Error fetching directory link. A read error occurred when fetching the
directory link field for a previous directory. This can occur when
setting up a link to the directory that is being written.
SEE ALSO
TIFFOpen(3TIFF), TIFFError(3TIFF), TIFFReadDirectory(3TIFF),
TIFFSetDirectory(3TIFF), libtiff(3TIFF)
Libtiff library home page: http://www.simplesystems.org/libtiff/
libtiff September 26, 2001 TIFFWriteDirectory(3TIFF)