man TIFFSetField () - set the value(s) of a tag in a TIFF file open for writing
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 (c 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 2 uint16, 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_PHOTOSHOP ? uint32,void* count, data 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 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.