TIFFWriteDirectory(3TIFF) Image Format Library C++ Reference Manual
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 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 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.
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TIFFWriteDirectory(3TIFF) Image Format Library C++ Reference Manual
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 ALSOTIFFOpen(3TIFF), TIFFError(3TIFF), TIFFReadDirectory(3TIFF),
TIFFSetDirectory(3TIFF), libtiff(3TIFF)
Libtiff library home page: http://www.remotesensing.org/libtiff/
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