[wxWidgets.git] / src / tiff / man / TIFFGetField.3tiff

.\"
.\" 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 TIFFGetField 3TIFF "March 18, 2005" "libtiff"
.SH NAME
TIFFGetField, TIFFVGetField \- get the value(s) of a tag in an open
.SM TIFF
file
.SH SYNOPSIS
.B "#include <tiffio.h>"
.sp
.BI "int TIFFGetField(TIFF *" tif ", ttag_t " tag ", " ... ")"
.sp
.B "#include <stdarg.h>"
.sp
.BI "int TIFFVGetField(TIFF *" tif ", ttag_t " tag ", va_list " ap ")"
.br
.BI "int TIFFGetFieldDefaulted(TIFF *" tif ", ttag_t " tag ", " ... ")"
.br
.BI "int TIFFVGetFieldDefaulted(TIFF *" tif ", ttag_t " tag ", va_list " ap ")"
.SH DESCRIPTION
.IR TIFFGetField
returns the value of a tag or pseudo-tag associated with the the current
directory of the opened
.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.) The
file must have been previously opened with
.IR TIFFOpen (3TIFF).
The tag is identified by
.IR tag ,
one of the values defined in the include file
.B tiff.h
(see also the table below). The type and number of values returned is
dependent on the tag being requested. The programming interface uses a
variable argument list as prescribed by the
.IR stdarg (3)
interface. The returned values should only be interpreted if
.IR TIFFGetField
returns 1.
.PP
.IR TIFFVGetField
is functionally equivalent to
.IR TIFFGetField
except that it takes a pointer to a variable argument list.
.I TIFFVGetField
is useful for layering interfaces on top of the functionality provided by
.IR TIFFGetField .
.PP
.IR TIFFGetFieldDefaulted
and
.IR TIFFVGetFieldDefaulted
are identical to 
.IR TIFFGetField
and
.IR TIFFVGetField ,
except that if a tag is not defined in the current directory and it has a
default value, then the default value is returned.
.PP
The tags understood by
.IR libtiff(3TIFF),
the number of parameter values, and the types for the returned values are
shown below. The data types are specified as in C and correspond to the types
used to specify tag values to
.IR TIFFSetField (3TIFF).
Remember that
.IR TIFFGetField
returns parameter values, so all the listed data types are pointers to storage
where values should be returned.
Consult the
.SM TIFF
specification (or relevant industry specification) for information on the
meaning of each tag and their possible values.
.PP
.nf
.ta \w'TIFFTAG_CONSECUTIVEBADFAXLINES'u+2n +\w'Count'u+2n +\w'TIFFFaxFillFunc*'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*
TIFFTAG_CLEANFAXDATA	1	uint16*
TIFFTAG_COLORMAP	3	uint16**	1<<BitsPerSample arrays
TIFFTAG_COMPRESSION	1	uint16*
TIFFTAG_CONSECUTIVEBADFAXLINES	1	uint32*
TIFFTAG_COPYRIGHT	1	char**
TIFFTAG_DATATYPE	1	uint16*
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	1	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	2	uint32*,void**	count, data
TIFFTAG_PLANARCONFIG	1	uint16*
TIFFTAG_PREDICTOR	1	uint16*
TIFFTAG_PRIMARYCHROMATICITIES	1	float**	6-entry array
TIFFTAG_REFERENCEBLACKWHITE	1	float**	6-entry array
TIFFTAG_RESOLUTIONUNIT	1	uint16*
TIFFTAG_RICHTIFFIPTC	2	uint32*,void**	count, data
TIFFTAG_ROWSPERSTRIP	1	uint32*
TIFFTAG_SAMPLEFORMAT	1	uint16*
TIFFTAG_SAMPLESPERPIXEL	1	uint16*
TIFFTAG_SMAXSAMPLEVALUE	1	double*
TIFFTAG_SMINSAMPLEVALUE	1	double*
TIFFTAG_SOFTWARE	1	char**
TIFFTAG_STONITS	1	double**
TIFFTAG_STRIPBYTECOUNTS	1	uint32**
TIFFTAG_STRIPOFFSETS	1	uint32**
TIFFTAG_SUBFILETYPE	1	uint32*
TIFFTAG_SUBIFD	2	uint16*,uint32**	count & offsets array
TIFFTAG_TARGETPRINTER	1	char**
TIFFTAG_THRESHHOLDING	1	uint16*
TIFFTAG_TILEBYTECOUNTS	1	uint32**
TIFFTAG_TILEDEPTH	1	uint32*
TIFFTAG_TILELENGTH	1	uint32*
TIFFTAG_TILEOFFSETS	1	uint32**
TIFFTAG_TILEWIDTH	1	uint32*
TIFFTAG_TRANSFERFUNCTION	1 or 3\(dg	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_YCBCRSUBSAMPLING	2	uint16*
TIFFTAG_YPOSITION	1	float*
TIFFTAG_YRESOLUTION	1	float*\(dd
.fi
\(dg If
.I SamplesPerPixel
is one, then a single array is returned; otherwise three arrays are returned.
.fi
\(dd The contents of this field are quite complex.  See 
.IR "The ICC Profile Format Specification" ,
Annex B.3 "Embedding ICC Profiles in TIFF Files" (available at
http://www.color.org) for an explanation.
.SH AUTOREGISTERED TAGS
If you can't find the tag in the table above that means this is an unsupported
tag and is not directly supported by
.BR libtiff(3TIFF)
library. You will still be able to read it's value if you know the data type of
that tag. For example, if you want to read the LONG value from the tag 33424
and ASCII string from the tag 36867 you can use the following code:
.PP
.RS
.nf
uint32  count;
void    *data;

TIFFGetField(tiff, 33424, &count, &data);
printf("Tag %d: %d, count %d\n", 33424, *(uint32 *)data, count);
TIFFGetField(tiff, 36867, &count, &data);
printf("Tag %d: %s, count %d\n", 36867, (char *)data, count);
.fi
.RE
.PP
.SH RETURN VALUES
1 is returned if the tag is defined in the current directory; otherwise a 0 is
returned.
.SH DIAGNOSTICS
All error messages are directed to the
.BR TIFFError (3TIFF)
routine.
.PP
.BR "Unknown field, tag 0x%x" .
An unknown tag was supplied.
.SH "SEE ALSO"
.BR TIFFOpen (3TIFF),
.BR TIFFSetField (3TIFF),
.BR TIFFSetDirectory (3TIFF),
.BR TIFFReadDirectory (3TIFF),
.BR TIFFWriteDirectory (3TIFF)
.BR libtiff (3TIFF),
.PP
Libtiff library home page:
.BR http://www.remotesensing.org/libtiff/
Commit	Line	Data
8414a40c VZ	1	.\"
	2	.\" Copyright (c) 1988-1997 Sam Leffler
	3	.\" Copyright (c) 1991-1997 Silicon Graphics, Inc.
	4	.\"
	5	.\" Permission to use, copy, modify, distribute, and sell this software and
	6	.\" its documentation for any purpose is hereby granted without fee, provided
	7	.\" that (i) the above copyright notices and this permission notice appear in
	8	.\" all copies of the software and related documentation, and (ii) the names of
	9	.\" Sam Leffler and Silicon Graphics may not be used in any advertising or
	10	.\" publicity relating to the software without the specific, prior written
	11	.\" permission of Sam Leffler and Silicon Graphics.
	12	.\"
	13	.\" THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
	14	.\" EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
	15	.\" WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
	16	.\"
	17	.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
	18	.\" ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
	19	.\" OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
	20	.\" WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
	21	.\" LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	22	.\" OF THIS SOFTWARE.
	23	.\"
	24	.if n .po 0
	25	.TH TIFFGetField 3TIFF "March 18, 2005" "libtiff"
	26	.SH NAME
	27	TIFFGetField, TIFFVGetField \- get the value(s) of a tag in an open
	28	.SM TIFF
	29	file
	30	.SH SYNOPSIS
	31	.B "#include <tiffio.h>"
	32	.sp
	33	.BI "int TIFFGetField(TIFF *" tif ", ttag_t " tag ", " ... ")"
	34	.sp
	35	.B "#include <stdarg.h>"
	36	.sp
	37	.BI "int TIFFVGetField(TIFF *" tif ", ttag_t " tag ", va_list " ap ")"
	38	.br
	39	.BI "int TIFFGetFieldDefaulted(TIFF *" tif ", ttag_t " tag ", " ... ")"
	40	.br
	41	.BI "int TIFFVGetFieldDefaulted(TIFF *" tif ", ttag_t " tag ", va_list " ap ")"
	42	.SH DESCRIPTION
	43	.IR TIFFGetField
	44	returns the value of a tag or pseudo-tag associated with the the current
	45	directory of the opened
	46	.SM TIFF
	47	file
	48	.IR tif .
	49	(A
	50	.I pseudo-tag
	51	is a parameter that is used to control the operation of the
	52	.SM TIFF
	53	library but whose value is not read or written to the underlying file.) The
	54	file must have been previously opened with
	55	.IR TIFFOpen (3TIFF).
	56	The tag is identified by
	57	.IR tag ,
	58	one of the values defined in the include file
	59	.B tiff.h
	60	(see also the table below). The type and number of values returned is
	61	dependent on the tag being requested. The programming interface uses a
	62	variable argument list as prescribed by the
	63	.IR stdarg (3)
	64	interface. The returned values should only be interpreted if
65	.IR TIFFGetField
66	returns 1.
67	.PP
68	.IR TIFFVGetField
69	is functionally equivalent to
70	.IR TIFFGetField
71	except that it takes a pointer to a variable argument list.
72	.I TIFFVGetField
73	is useful for layering interfaces on top of the functionality provided by
74	.IR TIFFGetField .
75	.PP
76	.IR TIFFGetFieldDefaulted
77	and
78	.IR TIFFVGetFieldDefaulted
79	are identical to
80	.IR TIFFGetField
81	and
82	.IR TIFFVGetField ,
83	except that if a tag is not defined in the current directory and it has a
84	default value, then the default value is returned.
85	.PP
86	The tags understood by
87	.IR libtiff(3TIFF),
88	the number of parameter values, and the types for the returned values are
89	shown below. The data types are specified as in C and correspond to the types
90	used to specify tag values to
91	.IR TIFFSetField (3TIFF).
92	Remember that
93	.IR TIFFGetField
94	returns parameter values, so all the listed data types are pointers to storage
95	where values should be returned.
96	Consult the
97	.SM TIFF
98	specification (or relevant industry specification) for information on the
99	meaning of each tag and their possible values.
100	.PP
101	.nf
102	.ta \w'TIFFTAG_CONSECUTIVEBADFAXLINES'u+2n +\w'Count'u+2n +\w'TIFFFaxFillFunc*'u+2n
103	\fITag Name\fP \fICount\fP \fITypes\fP \fINotes\fP
104	.sp 5p
105	TIFFTAG_ARTIST 1 char**
106	TIFFTAG_BADFAXLINES 1 uint32*
107	TIFFTAG_BITSPERSAMPLE 1 uint16*
108	TIFFTAG_CLEANFAXDATA 1 uint16*
109	TIFFTAG_COLORMAP 3 uint16** 1<<BitsPerSample arrays
110	TIFFTAG_COMPRESSION 1 uint16*
111	TIFFTAG_CONSECUTIVEBADFAXLINES 1 uint32*
112	TIFFTAG_COPYRIGHT 1 char**
113	TIFFTAG_DATATYPE 1 uint16*
114	TIFFTAG_DATETIME 1 char**
115	TIFFTAG_DOCUMENTNAME 1 char**
116	TIFFTAG_DOTRANGE 2 uint16*
117	TIFFTAG_EXTRASAMPLES 2 uint16,uint16* count & types array
118	TIFFTAG_FAXFILLFUNC 1 TIFFFaxFillFunc* G3/G4 compression pseudo-tag
119	TIFFTAG_FAXMODE 1 int* G3/G4 compression pseudo-tag
120	TIFFTAG_FILLORDER 1 uint16*
121	TIFFTAG_GROUP3OPTIONS 1 uint32*
122	TIFFTAG_GROUP4OPTIONS 1 uint32*
123	TIFFTAG_HALFTONEHINTS 2 uint16*
124	TIFFTAG_HOSTCOMPUTER 1 char**
125	TIFFTAG_ICCPROFILE 2 uint32,void* count, profile data
126	TIFFTAG_IMAGEDEPTH 1 uint32*
127	TIFFTAG_IMAGEDESCRIPTION 1 char**
128	TIFFTAG_IMAGELENGTH 1 uint32*
129	TIFFTAG_IMAGEWIDTH 1 uint32*
130	TIFFTAG_INKNAMES 1 char**
131	TIFFTAG_INKSET 1 uint16*
132	TIFFTAG_JPEGCOLORMODE 1 int* JPEG pseudo-tag
133	TIFFTAG_JPEGQUALITY 1 int* JPEG pseudo-tag
134	TIFFTAG_JPEGTABLES 2 uint32,void* count & tables
135	TIFFTAG_JPEGTABLESMODE 1 int* JPEG pseudo-tag
136	TIFFTAG_MAKE 1 char**
137	TIFFTAG_MATTEING 1 uint16*
138	TIFFTAG_MAXSAMPLEVALUE 1 uint16*
139	TIFFTAG_MINSAMPLEVALUE 1 uint16*
140	TIFFTAG_MODEL 1 char**
141	TIFFTAG_ORIENTATION 1 uint16*
142	TIFFTAG_PAGENAME 1 char**
143	TIFFTAG_PAGENUMBER 2 uint16*
144	TIFFTAG_PHOTOMETRIC 1 uint16*
145	TIFFTAG_PHOTOSHOP 2 uint32,void* count, data
146	TIFFTAG_PLANARCONFIG 1 uint16*
147	TIFFTAG_PREDICTOR 1 uint16*
148	TIFFTAG_PRIMARYCHROMATICITIES 1 float** 6-entry array
80ed523f	149	TIFFTAG_REFERENCEBLACKWHITE 1 float** 6-entry array
8414a40c VZ	150	TIFFTAG_RESOLUTIONUNIT 1 uint16*
	151	TIFFTAG_RICHTIFFIPTC 2 uint32,void* count, data
	152	TIFFTAG_ROWSPERSTRIP 1 uint32*
	153	TIFFTAG_SAMPLEFORMAT 1 uint16*
	154	TIFFTAG_SAMPLESPERPIXEL 1 uint16*
	155	TIFFTAG_SMAXSAMPLEVALUE 1 double*
	156	TIFFTAG_SMINSAMPLEVALUE 1 double*
	157	TIFFTAG_SOFTWARE 1 char**
	158	TIFFTAG_STONITS 1 double**
	159	TIFFTAG_STRIPBYTECOUNTS 1 uint32**
	160	TIFFTAG_STRIPOFFSETS 1 uint32**
	161	TIFFTAG_SUBFILETYPE 1 uint32*
	162	TIFFTAG_SUBIFD 2 uint16,uint32* count & offsets array
	163	TIFFTAG_TARGETPRINTER 1 char**
	164	TIFFTAG_THRESHHOLDING 1 uint16*
	165	TIFFTAG_TILEBYTECOUNTS 1 uint32**
	166	TIFFTAG_TILEDEPTH 1 uint32*
	167	TIFFTAG_TILELENGTH 1 uint32*
	168	TIFFTAG_TILEOFFSETS 1 uint32**
	169	TIFFTAG_TILEWIDTH 1 uint32*
	170	TIFFTAG_TRANSFERFUNCTION 1 or 3\(dg uint16**1<<BitsPerSample entry arrays
	171	TIFFTAG_WHITEPOINT 1 float** 2-entry array
	172	TIFFTAG_XMLPACKET 2 uint32,void* count, data
	173	TIFFTAG_XPOSITION 1 float*
	174	TIFFTAG_XRESOLUTION 1 float*
	175	TIFFTAG_YCBCRCOEFFICIENTS 1 float** 3-entry array
	176	TIFFTAG_YCBCRPOSITIONING 1 uint16*
	177	TIFFTAG_YCBCRSUBSAMPLING 2 uint16*
	178	TIFFTAG_YPOSITION 1 float*
	179	TIFFTAG_YRESOLUTION 1 float*\(dd
	180	.fi
	181	\(dg If
	182	.I SamplesPerPixel
	183	is one, then a single array is returned; otherwise three arrays are returned.
	184	.fi
	185	\(dd The contents of this field are quite complex. See
	186	.IR "The ICC Profile Format Specification" ,
	187	Annex B.3 "Embedding ICC Profiles in TIFF Files" (available at
	188	http://www.color.org) for an explanation.
	189	.SH AUTOREGISTERED TAGS
80ed523f VZ	190	If you can't find the tag in the table above that means this is an unsupported
	191	tag and is not directly supported by
	192	.BR libtiff(3TIFF)
	193	library. You will still be able to read it's value if you know the data type of
8414a40c VZ	194	that tag. For example, if you want to read the LONG value from the tag 33424
	195	and ASCII string from the tag 36867 you can use the following code:
	196	.PP
	197	.RS
	198	.nf
80ed523f	199	uint32 count;
8414a40c VZ	200	void *data;
	201
	202	TIFFGetField(tiff, 33424, &count, &data);
	203	printf("Tag %d: %d, count %d\n", 33424, (uint32 )data, count);
	204	TIFFGetField(tiff, 36867, &count, &data);
	205	printf("Tag %d: %s, count %d\n", 36867, (char *)data, count);
	206	.fi
	207	.RE
	208	.PP
8414a40c VZ	209	.SH RETURN VALUES
	210	1 is returned if the tag is defined in the current directory; otherwise a 0 is
	211	returned.
	212	.SH DIAGNOSTICS
	213	All error messages are directed to the
	214	.BR TIFFError (3TIFF)
	215	routine.
	216	.PP
	217	.BR "Unknown field, tag 0x%x" .
	218	An unknown tag was supplied.
	219	.SH "SEE ALSO"
	220	.BR TIFFOpen (3TIFF),
	221	.BR TIFFSetField (3TIFF),
	222	.BR TIFFSetDirectory (3TIFF),
	223	.BR TIFFReadDirectory (3TIFF),
	224	.BR TIFFWriteDirectory (3TIFF)
	225	.BR libtiff (3TIFF),
	226	.PP
	227	Libtiff library home page:
	228	.BR http://www.remotesensing.org/libtiff/