TIFFSetField

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUES
RETURN VALUES
DIAGNOSTICS
SEE ALSO

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_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_ICCPROFILE              2      uint32,void*      count, profile data*

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 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.