TIFFSetField(3TIFF)                                        TIFFSetField(3TIFF)



NAME
       TIFFSetField, TIFFVSetField - set the value(s) of a tag in a TIFF file
       open for writing

SYNOPSIS
       #include <tiffio.h>

       int TIFFSetField(TIFF *tif, ttag_t tag, ...)

       #include <stdarg.h>

       int TIFFVSetField(TIFF *tif, ttag_t tag, va_list ap)

DESCRIPTION
       TIFFSetField sets the value of a field or pseudo-tag in the current
       directory associated with the open TIFF file tif.  (A pseudo-tag is a
       parameter that is used to control the operation of the TIFF library but
       whose value is not read or written to the underlying file.)  To set the
       value of a field the file must have been previously opened for writing
       with TIFFOpen(3TIFF); pseudo-tags can be set whether the file was
       opened for reading or writing.  The field is identified by tag, one of
       the values defined in the include file tiff.h (see also the table
       below).  The actual value is specified using a variable argument list,
       as prescribed by the stdarg(3) interface (or, on some machines, the
       varargs(3) interface.)

       TIFFVSetField is functionally equivalent to TIFFSetField except that it
       takes a pointer to a variable argument list.  TIFFVSetField is useful
       for writing routines that are layered on top of the functionality
       provided by TIFFSetField.

       The tags understood by libtiff, the number of parameter values, and the
       expected types for the parameter values are shown below.  The data
       types are: char* is null-terminated string and corresponds to the ASCII
       data type; uint16 is an unsigned 16-bit value; uint32 is an unsigned
       32-bit value; uint16* is an array of unsigned 16-bit values.  void* is
       an array of data values of unspecified type.

       Consult the TIFF specification for information on the meaning of each
       tag.

       Tag Name                        Count  Types              Notes
       TIFFTAG_ARTIST                  1      char*
       TIFFTAG_BADFAXLINES             1      uint32
       TIFFTAG_BITSPERSAMPLE           1      uint16             -
       TIFFTAG_CLEANFAXDATA            1      uint16
       TIFFTAG_COLORMAP                3      uint16*            1<<BitsPerSample arrays
       TIFFTAG_COMPRESSION             1      uint16             -
       TIFFTAG_CONSECUTIVEBADFAXLINES  1      uint32
       TIFFTAG_COPYRIGHT               1      char*
       TIFFTAG_DATETIME                1      char*
       TIFFTAG_DOCUMENTNAME            1      char*
       TIFFTAG_DOTRANGE                2      uint16
       TIFFTAG_EXTRASAMPLES            2      uint16,uint16*     - count & types array
       TIFFTAG_FAXFILLFUNC             1      TIFFFaxFillFunc    G3/G4 compression pseudo-tag
       TIFFTAG_FAXMODE                 1      int                - G3/G4 compression pseudo-tag
       TIFFTAG_FILLORDER               1      uint16             -
       TIFFTAG_GROUP3OPTIONS           1      uint32             -
       TIFFTAG_GROUP4OPTIONS           1      uint32             -
       TIFFTAG_HALFTONEHINTS           2      uint16
       TIFFTAG_HOSTCOMPUTER            1      char*
       TIFFTAG_ICCPROFILE              2      uint32,void*       count, profile data
       TIFFTAG_IMAGEDEPTH              1      uint32             -
       TIFFTAG_IMAGEDESCRIPTION        1      char*
       TIFFTAG_IMAGELENGTH             1      uint32
       TIFFTAG_IMAGEWIDTH              1      uint32             -
       TIFFTAG_INKNAMES                2      uint16, char*
       TIFFTAG_INKSET                  1      uint16             -
       TIFFTAG_JPEGCOLORMODE           1      int                - JPEG pseudo-tag
       TIFFTAG_JPEGQUALITY             1      int                JPEG pseudo-tag
       TIFFTAG_JPEGTABLES              2      uint32*,void*      - count & tables
       TIFFTAG_JPEGTABLESMODE          1      int                - JPEG pseudo-tag
       TIFFTAG_MAKE                    1      char*
       TIFFTAG_MATTEING                1      uint16             -
       TIFFTAG_MAXSAMPLEVALUE          1      uint16
       TIFFTAG_MINSAMPLEVALUE          1      uint16
       TIFFTAG_MODEL                   1      char*
       TIFFTAG_ORIENTATION             1      uint16
       TIFFTAG_PAGENAME                1      char*
       TIFFTAG_PAGENUMBER              2      uint16
       TIFFTAG_PHOTOMETRIC             1      uint16
       TIFFTAG_PHOTOSHOP               ?      uint32,void*       count, data
       TIFFTAG_PLANARCONFIG            1      uint16             -
       TIFFTAG_PREDICTOR               1      uint16             -
       TIFFTAG_PRIMARYCHROMATICITIES   1      float*             6-entry array
       TIFFTAG_REFERENCEBLACKWHITE     1      float*             - 6-entry array
       TIFFTAG_RESOLUTIONUNIT          1      uint16
       TIFFTAG_RICHTIFFIPTC            2      uint32,void*       count, data
       TIFFTAG_ROWSPERSTRIP            1      uint32             - must be > 0
       TIFFTAG_SAMPLEFORMAT            1      uint16             -
       TIFFTAG_SAMPLESPERPIXEL         1      uint16             - value must be <= 4
       TIFFTAG_SMAXSAMPLEVALUE         1      double
       TIFFTAG_SMINSAMPLEVALUE         1      double
       TIFFTAG_SOFTWARE                1      char*
       TIFFTAG_STONITS                 1      double             -
       TIFFTAG_SUBFILETYPE             1      uint32
       TIFFTAG_SUBIFD                  2      uint16,uint32*     count & offsets array
       TIFFTAG_TARGETPRINTER           1      char*
       TIFFTAG_THRESHHOLDING           1      uint16
       TIFFTAG_TILEDEPTH               1      uint32             -
       TIFFTAG_TILELENGTH              1      uint32             - must be a multiple of 8
       TIFFTAG_TILEWIDTH               1      uint32             - must be a multiple of 8
       TIFFTAG_TRANSFERFUNCTION        1 or 3= uint16*           1<<BitsPerSample entry arrays
       TIFFTAG_WHITEPOINT              1      float*             2-entry array
       TIFFTAG_XMLPACKET               2      uint32,void*       count, data
       TIFFTAG_XPOSITION               1      float
       TIFFTAG_XRESOLUTION             1      float
       TIFFTAG_YCBCRCOEFFICIENTS       1      float*             - 3-entry array
       TIFFTAG_YCBCRPOSITIONING        1      uint16             -
       TIFFTAG_YCBCRSAMPLING           2      uint16             -
       TIFFTAG_YPOSITION               1      float
       TIFFTAG_YRESOLUTION             1      float
       - Tag may not have its values changed once data is written.
       = If SamplesPerPixel is one, then a single array is passed; otherwise
       three arrays should be passed.
       * The contents of this field are quite complex.  See The ICC Profile
       Format Specification, Annex B.3 "Embedding ICC Profiles in TIFF Files"
       (available at http://www.color.org) for an explanation.

RETURN VALUES
       1 is returned if the operation was successful.  Otherwise, 0 is
       returned if an error was detected.

DIAGNOSTICS
       All error messages are directed to the TIFFError(3TIFF) routine.

       %s: Cannot modify tag "%s" while writing.  Data has already been
       written to the file, so the specified tag's value can not be changed.
       This restriction is applied to all tags that affect the format of
       written data.

       %d: Bad value for "%s".  An invalid value was supplied for the named
       tag.

SEE ALSO
       TIFFOpen(3TIFF), TIFFGetField(3TIFF), TIFFSetDirectory(3TIFF),
       TIFFWriteDirectory(3TIFF), TIFFReadDirectory(3TIFF), libtiff(3TIFF)

       Libtiff library home page: http://www.remotesensing.org/libtiff/



libtiff                        October 29, 2004            TIFFSetField(3TIFF)
