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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*             + 2*SamplesPerPixel 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 3dd 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.
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 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/