.\" $Id: TIFFSetField.3tiff,v 1.5 2010-05-06 02:54:46 olivier Exp $

.\"

.\" Copyright (c) 1988-1997 Sam Leffler

.\" Copyright (c) 1991-1997 Silicon Graphics, Inc.

.\"

.\" Permission to use, copy, modify, distribute, and sell this software and 

.\" its documentation for any purpose is hereby granted without fee, provided

.\" that (i) the above copyright notices and this permission notice appear in

.\" all copies of the software and related documentation, and (ii) the names of

.\" Sam Leffler and Silicon Graphics may not be used in any advertising or

.\" publicity relating to the software without the specific, prior written

.\" permission of Sam Leffler and Silicon Graphics.

.\" 

.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 

.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 

.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  

.\" 

.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR

.\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,

.\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,

.\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 

.\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 

.\" OF THIS SOFTWARE.

.\"

.if n .po 0

.TH TIFFSetField 3TIFF "October 29, 2004" "libtiff"

.SH NAME

TIFFSetField, TIFFVSetField \- set the value(s) of a tag in a

.SM TIFF

file open for writing

.SH SYNOPSIS

.B "#include <tiffio.h>"</tiffio.h>

.sp

.BI "int TIFFSetField(TIFF *" tif ", ttag_t " tag ", " ... ")"

.sp

.B "#include <stdarg.h>"</stdarg.h>

.sp

.BI "int TIFFVSetField(TIFF *" tif ", ttag_t " tag ", va_list " ap ")"

.SH DESCRIPTION

.IR TIFFSetField

sets the value of a field

or pseudo-tag in the current directory associated with

the open

.SM TIFF

file

.IR tif .

(A

.I pseudo-tag 

is a parameter that is used to control the operation of the

.SM 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

.IR TIFFOpen (3TIFF);

pseudo-tags can be set whether the file was opened for reading

or writing.

The field is identified by

.IR tag ,

one of the values defined in the include file

.B tiff.h

(see also the table below).

The actual value is specified using a variable argument list,

as prescribed by the

.IR stdarg (3)

interface (\c

or, on some machines, the

.IR varargs (3)

interface.)

.PP

.IR TIFFVSetField

is functionally equivalent to

.IR TIFFSetField

except that it takes a pointer to a variable

argument list.

.I TIFFVSetField

is useful for writing routines that are layered

on top of the functionality provided by

.IR TIFFSetField .

.PP

The tags understood by

.IR libtiff ,

the number of parameter values, and the

expected types for the parameter values are shown below.

The data types are:

.I char*

is null-terminated string and corresponds to the

.SM ASCII

data type;

.I uint16

is an unsigned 16-bit value;

.I uint32

is an unsigned 32-bit value;

.I uint16*

is an array of unsigned 16-bit values.

.I void*

is an array of data values of unspecified type.

Consult the

.SM TIFF

specification for information on the meaning of each tag.

.PP

.nf

.ta \w'TIFFTAG_CONSECUTIVEBADFAXLINES'u+2n +\w'Count'u+2n +\w'TIFFFaxFillFunc \(dg'u+2n

\fITag Name\fP	\fICount\fP	\fITypes\fP	\fINotes\fP

.sp 5p

TIFFTAG_ARTIST	1	char*

TIFFTAG_BADFAXLINES	1	uint32

TIFFTAG_BITSPERSAMPLE	1	uint16	\(dg

TIFFTAG_CLEANFAXDATA	1	uint16

TIFFTAG_COLORMAP	3	uint16*	1<

TIFFTAG_COMPRESSION	1	uint16	\(dg

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*	\(dg count & types array

TIFFTAG_FAXFILLFUNC	1	TIFFFaxFillFunc	G3/G4 compression pseudo-tag

TIFFTAG_FAXMODE	1	int	\(dg G3/G4 compression pseudo-tag

TIFFTAG_FILLORDER	1	uint16	\(dg

TIFFTAG_GROUP3OPTIONS	1	uint32	\(dg

TIFFTAG_GROUP4OPTIONS	1	uint32	\(dg

TIFFTAG_HALFTONEHINTS	2	uint16

TIFFTAG_HOSTCOMPUTER	1	char*

TIFFTAG_ICCPROFILE	2	uint32,void*	count, profile data

TIFFTAG_IMAGEDEPTH	1	uint32	\(dg

TIFFTAG_IMAGEDESCRIPTION	1	char*

TIFFTAG_IMAGELENGTH	1	uint32

TIFFTAG_IMAGEWIDTH	1	uint32	\(dg

TIFFTAG_INKNAMES	2	uint16, char*

TIFFTAG_INKSET	1	uint16	\(dg

TIFFTAG_JPEGCOLORMODE	1	int	\(dg JPEG pseudo-tag

TIFFTAG_JPEGQUALITY	1	int	JPEG pseudo-tag

TIFFTAG_JPEGTABLES	2	uint32*,void*	\(dg count & tables

TIFFTAG_JPEGTABLESMODE	1	int	\(dg JPEG pseudo-tag

TIFFTAG_MAKE	1	char*

TIFFTAG_MATTEING	1	uint16	\(dg

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	\(dg

TIFFTAG_PREDICTOR	1	uint16	\(dg

TIFFTAG_PRIMARYCHROMATICITIES	1	float*	6-entry array

TIFFTAG_REFERENCEBLACKWHITE	1	float*	\(dg 6-entry array

TIFFTAG_RESOLUTIONUNIT	1	uint16

TIFFTAG_RICHTIFFIPTC	2	uint32,void*	count, data

TIFFTAG_ROWSPERSTRIP	1	uint32	\(dg must be > 0

TIFFTAG_SAMPLEFORMAT	1	uint16	\(dg

TIFFTAG_SAMPLESPERPIXEL	1	uint16	\(dg value must be <= 4

TIFFTAG_SMAXSAMPLEVALUE	1	double

TIFFTAG_SMINSAMPLEVALUE	1	double

TIFFTAG_SOFTWARE	1	char*

TIFFTAG_STONITS	1	double	\(dg

TIFFTAG_SUBFILETYPE	1	uint32

TIFFTAG_SUBIFD	2	uint16,uint32*	count & offsets array

TIFFTAG_TARGETPRINTER	1	char*

TIFFTAG_THRESHHOLDING	1	uint16

TIFFTAG_TILEDEPTH	1	uint32	\(dg

TIFFTAG_TILELENGTH	1	uint32	\(dg must be a multiple of 8

TIFFTAG_TILEWIDTH	1	uint32	\(dg must be a multiple of 8

TIFFTAG_TRANSFERFUNCTION	1 or 3\(dd uint16*	1<

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*	\(dg 3-entry array

TIFFTAG_YCBCRPOSITIONING	1	uint16	\(dg

TIFFTAG_YCBCRSAMPLING	2	uint16	\(dg

TIFFTAG_YPOSITION	1	float

TIFFTAG_YRESOLUTION	1	float

.fi

.sp 5p

\(dg Tag may not have its values changed once data is written.

.br

.fi

\(dd

If

.I SamplesPerPixel

is one, then a single array is passed; otherwise three arrays should be

passed.

.fi

* The contents of this field are quite complex.  See 

.BR "The ICC Profile Format Specification" ,

Annex B.3 "Embedding ICC Profiles in TIFF Files"

(available at http://www.color.org) for an explanation.

.br

.SH "RETURN VALUES"

1 is returned if the operation was successful.

Otherwise, 0 is returned if an error was detected.

.SH DIAGNOSTICS

All error messages are directed to the

.BR TIFFError (3TIFF)

routine.

.PP

\fB%s: Cannot modify tag "%s" while writing\fP.

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.

.PP

\fB%d: Bad value for "%s"\fP.

An invalid value was supplied for the named tag.

.SH "SEE ALSO"

.BR TIFFOpen (3TIFF),

.BR TIFFGetField (3TIFF),

.BR TIFFSetDirectory (3TIFF),

.BR TIFFWriteDirectory (3TIFF),

.BR TIFFReadDirectory (3TIFF),

.BR libtiff (3TIFF)

.PP

Libtiff library home page:

.BR http://www.remotesensing.org/libtiff/