/usr/man2/cat.3/TIFFVGetFieldDefaulted.3.Z(/usr/man2/cat.3/TIFFVGetFieldDefaulted.3.Z)
NAME
TIFFGetField, TIFFVGetField - get the value(s) of a tag in an open TIFF
file
SYNOPSIS
#include <tiffio.h>
int TIFFGetField(TIFF *tif, ttag_t tag, ...)
#include <stdarg.h>
int TIFFVGetField(TIFF *tif, ttag_t tag, va_list ap)
int TIFFGetFieldDefaulted(TIFF *tif, ttag_t tag, ...)
int TIFFVGetFieldDefaulted(TIFF *tif, ttag_t tag, va_list ap)
DESCRIPTION
TIFFGetField returns the value of a tag or pseudo-tag associated with
the the current directory of the opened 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.)
The file must have been previously opened with TIFFOpen(3TIFF). The
tag is identified by tag, one of the values defined in the include file
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 stdarg(3)
interface. The returned values should only be interpreted if TIFFGet-
Field returns 1.
TIFFVGetField is functionally equivalent to TIFFGetField except that it
takes a pointer to a variable argument list. TIFFVGetField is useful
for layering interfaces on top of the functionality provided by
TIFFGetField.
TIFFGetFieldDefaulted and TIFFVGetFieldDefaulted are identical to
TIFFGetField and 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.
The tags understood by 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 TIFFSetField(3TIFF). Remember that TIFFGetField returns
parameter values, so all the listed data types are pointers to storage
where values should be returned. Consult the TIFF specification for
information on the meaning of each tag and their possible values.
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_DATATYPE 1 uint16*
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_IMAGEDEPTH 1 uint32*
TIFFTAG_IMAGEDESCRIPTION 1 char**
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*
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 uint16**1<<BitsPerSample entry arrays
TIFFTAG_WHITEPOINT 1 float** 2-entry array
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*
TIFFTAG_ICCPROFILE 2 uint32*,void** count, profile data
If SamplesPerPixel is one, then a single array is returned; otherwise
three arrays are returned.
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.
AUTOREGISTERED TAGS
If you can't find the tag in the table above that means this is unsup-
ported tag. But you 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:
uint16 count;
void *data;
TIFFGetField(tiff, 33424, &count, &data);
printf("Tag %d: %d, count %d0, 33424, *(uint32 *)data, count);
TIFFGetField(tiff, 36867, &count, &data);
printf("Tag %d: %s, count %d0, 36867, (char *)data, count);
is not supported by libtiff(3TIFF), library
RETURN VALUES
1 is returned if the tag is defined in the current directory; otherwise
a 0 is returned.
DIAGNOSTICS
All error messages are directed to the TIFFError(3TIFF) routine.
Unknown field, tag 0x%x. An unknown tag was supplied.
SEE ALSO
libtiff(3TIFF), TIFFOpen(3TIFF), TIFFSetField(3TIFF), TIFFSetDirec-
tory(3TIFF), TIFFReadDirectory(3TIFF), TIFFWriteDirectory(3TIFF)
libtiff March 18, 2005 TIFFGetField(3TIFF)
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