# TIFFSetField

Section: Misc. Reference Manual Pages (3T)
Updated: August 28, 1997
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## NAME

TIFFSetField - 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(3T); 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_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 dd                 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_ICCPROFILE              2      uint32,void*       count, profile data*

+ Tag may not have its values changed once data is written.
dd 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 tag is defined in the current directory; otherwise a 0 is returned.

## 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(3T) 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(3T), TIFFOpen(3T), TIFFGetField(3T), TIFFSetDirectory(3T), TIFFWriteDirectory(3T), TIFFReadDirectory(3T)

## Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUES
RETURN VALUES
DIAGNOSTICS
SEE ALSO

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Time: 01:31:38 GMT, November 23, 1999