TIFFSetField
TIFFSetField(3T) TIFFSetField(3T)
NAME
TIFFSetField - set the value(s) of a tag in a TIFF file open for writ-
ing
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 pre-
scribed 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 pro-
vided 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 writ-
ten 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)
August 28, 1997 TIFFSetField(3T)
