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 count. A write error occurred when writing
the count of fields in the directory.

Error writing directory contents. A write error occurred when
writing the directory fields.

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)