NAME¶

TIFFSetDirectory - set the current directory for an open TIFF file

SYNOPSIS¶

#include <tiffio.h>

DESCRIPTION¶

TIFFSetDirectory() changes the current directory and reads its contents with TIFFReadDirectory(). The parameter dirnum specifies the subfile/directory as an integer number, with the first directory numbered zero.

TIFFSetSubDirectory() acts like TIFFSetDirectory(), except the directory is specified as a file offset instead of an index; this is required for accessing subdirectories linked through a SubIFD tag.

In the case of several SubIFDs of a main image, there are two possibilities that are not even mutually exclusive.

LibTiff does support SubIFD chains partially. When a SubIFD tag is activated with TIFFSetSubDirectory(), TIFFReadDirectory() is able to parse through the SubIFD chain. The tif_curdir is just incremented from its current value and thus gets arbitrary values when parsing through SubIFD chains. TIFFSetDirectory() only works with main-IFD chains because allways starts with the first main-IFD and thus is able to reset the SubIFD reading chain to the main-IFD chain.

Directory query functions TIFFCurrentDirectory(), TIFFCurrentDirOffset(), TIFFLastDirectory() and TIFFNumberOfDirectories() retrieve information about directories in an open TIFF file. Be aware that until a directory is not written to file AND read back, the query functions won't retrieve the correct information!

RETURN VALUES¶

On successful return 1 is returned. Otherwise, 0 is returned if dirnum or diroff specifies a non-existent directory, or if an error was encountered while reading the directory's contents.

DIAGNOSTICS¶

All error messages are directed to the TIFFErrorExtR() routine.

"%s: Error fetching directory count":

"%s: Error fetching directory link":

SEE ALSO¶

TIFFquery (3tiff), TIFFOpen (3tiff), TIFFCreateDirectory (3tiff), TIFFCustomDirectory (3tiff), TIFFWriteDirectory (3tiff), TIFFReadDirectory (3tiff), libtiff (3tiff)

AUTHOR¶

LibTIFF contributors

COPYRIGHT¶

1988-2023, LibTIFF contributors