TIFFWriteDirectory
TIFFWriteDirectory(3T) TIFFWriteDirectory(3T)
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. Applica-
tions only need to call TIFFWriteDirectory when writing multiple sub-
files 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 TIFFWriteDi-
rectory, 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 preceeding 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 read-
able. 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 com-
plete, 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(3T) routine.
Error post-encoding before directory write. Before writing the con-
tents 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 con-
tents 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 writ-
ing 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
libtiff(3T), TIFFOpen(3T), TIFFError(3T), TIFFReadDirectory(3T), TIFF-
SetDirectory(3T)
September 26, 2001 TIFFWriteDirectory(3T)
