tiffsetfield(3)
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(3); 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 TIFF_
SetField.
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-termi
nated 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 val
ues. 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 = - 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 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 tag is defined in the current direc
tory; 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(3) rou
tine.
%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(3), TIFFOpen(3), TIFFGetField(3), TIFFSetDirec_ tory(3), TIFFWriteDirectory(3), TIFFReadDirectory(3)