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  con-
       trol  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 writ-
       ing.  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-ter-
       minated  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_FAXMODE                 1      int                G3/G4 compression pseudo-tag
       TIFFTAG_FAXFILLFUNC             1      TIFFFaxFillFunc   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_IMAGEDESCRIPTION        1      char*
       TIFFTAG_IMAGEDEPTH              1      uint32
       TIFFTAG_IMAGELENGTH             1      uint32
       TIFFTAG_IMAGEWIDTH              1      uint32
       TIFFTAG_INKNAMES                1      char*
       TIFFTAG_INKSET                  1      uint16
       TIFFTAG_JPEGTABLES              2      uint32*,void*      count & tables
       TIFFTAG_JPEGQUALITY             1      int               JPEG pseudo-tag
       TIFFTAG_JPEGCOLORMODE           1      int                JPEG pseudo-tag
       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_PLANARCONFIG            1      uint16
       TIFFTAG_PREDICTOR               1      uint16
       TIFFTAG_PRIMARYCHROMATICITIES   1      float*            6-entry array
       TIFFTAG_REFERENCEBLACKWHITE     1      float*             2*SamplesPerPixel array
       TIFFTAG_RESOLUTIONUNIT          1      uint16
       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_XPOSITION               1      float
       TIFFTAG_XRESOLUTION             1      float
       TIFFTAG_WHITEPOINT              1      float*            2-entry array
       TIFFTAG_YCBCRCOEFFICIENTS       1      float*             3-entry array
       TIFFTAG_YCBCRPOSITIONING        1      uint16
       TIFFTAG_YCBCRSAMPLING           2      uint16
       TIFFTAG_YPOSITION               1      float
       TIFFTAG_YRESOLUTION             1      float
       TIFFTAG_PHOTOSHOP               ?      uint32,void*      count, data
       TIFFTAG_ICCPROFILE              2      uint32,void*      count, profile data*
        Tag may not have its values changed once data is  writ-
       ten.
         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.  Other-
       wise, 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
       libtiff(3TIFF),   TIFFOpen(3TIFF),  TIFFGetField(3TIFF),
       TIFFSetDirectory(3TIFF),      TIFFWriteDirectory(3TIFF),
       TIFFReadDirectory(3TIFF)



libtiff                 October 29, 2004    TIFFSetField(3TIFF)
