TIFFGetField(3T) UNIX System V(June 18, 1991) TIFFGetField(3T)
NAME
TIFFGetField, TIFFVGetField - get the value(s) of a tag in an open TIFF
file
SYNOPSIS
#include <tiffio.h>
int TIFFGetField(TIFF* tif, int tag, ...)
#include <varargs.h>
int TIFFVGetField(TIFF* tif, int tag, va_list ap)
DESCRIPTION
TIFFGetField() returns the value of a tag in the current directory
associated with the open TIFF file tif. The file must have been
previously opened with TIFFOpen(3T). 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 varargs(3) interface. A 1 is returned if the tag is
defined in the current directory; otherwise a 0 is returned. The
returned values should only be interpreted if TIFFGetField() 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 of
TIFFGetField.
The tags understood by libtiff, 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(3T). 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 u_long*
TIFFTAG_BITSPERSAMPLE 1 u_short*
TIFFTAG_CLEANFAXDATA 1 u_short*
TIFFTAG_COLORMAP 3 u_short** 1<<BitsPerSample arrays
TIFFTAG_COLORRESPONSECURVE 3 u_short** 1<<BitsPerSample entry arrays
TIFFTAG_COLORRESPONSEUNIT 1 u_short*
TIFFTAG_COMPRESSION 1 u_short*
TIFFTAG_CONSECUTIVEBADFAXLINES 1 u_long*
TIFFTAG_DATATYPE 1 u_short*
TIFFTAG_DATETIME 1 char**
TIFFTAG_DOCUMENTNAME 1 char**
TIFFTAG_FILLORDER 1 u_short*
TIFFTAG_GRAYRESPONSECURVE 1 u_short** 1<<BitsPerSample entry array
TIFFTAG_GRAYRESPONSEUNIT 1 u_short*
TIFFTAG_GROUP3OPTIONS 1 u_long*
TIFFTAG_GROUP4OPTIONS 1 u_long*
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TIFFGetField(3T) UNIX System V(June 18, 1991) TIFFGetField(3T)
TIFFTAG_HOSTCOMPUTER 1 char**
TIFFTAG_IMAGEDESCRIPTION 1 char**
TIFFTAG_IMAGEDEPTH 1 u_long*
TIFFTAG_IMAGELENGTH 1 u_long*
TIFFTAG_IMAGEWIDTH 1 u_long*
TIFFTAG_INKSET 1 u_short*
TIFFTAG_JPEGPROC 1 u_short*
TIFFTAG_JPEGQTABLEPREC 1 u_short*
TIFFTAG_JPEGQTABLES 1 u_short*** SamplesPerPixel 64-entry arrays
TIFFTAG_JPEGDCTABLES 1 u_char*** SamplesPerPixel arrays
TIFFTAG_JPEGACTABLES 1 u_char*** SamplesPerPixel arrays
TIFFTAG_LUMACOEFS 1 u_short*
TIFFTAG_MAKE 1 char**
TIFFTAG_MATTEING 1 u_short*
TIFFTAG_MAXSAMPLEVALUE 1 u_short*
TIFFTAG_MINSAMPLEVALUE 1 u_short*
TIFFTAG_MODEL 1 char**
TIFFTAG_ORIENTATION 1 u_short*
TIFFTAG_PAGENAME 1 char**
TIFFTAG_PAGENUMBER 2 u_short*
TIFFTAG_PHOTOMETRIC 1 u_short*
TIFFTAG_PLANARCONFIG 1 u_short*
TIFFTAG_PREDICTOR 1 u_short*
TIFFTAG_RESOLUTIONUNIT 1 u_short*
TIFFTAG_ROWSPERSTRIP 1 u_long*
TIFFTAG_SAMPLESPERPIXEL 1 u_short* value must be <= 4
TIFFTAG_SOFTWARE 1 char**
TIFFTAG_STRIPOFFSETS 1 u_long**
TIFFTAG_STRIPBYTECOUNTS 1 u_long**
TIFFTAG_SUBFILETYPE 1 u_long*
TIFFTAG_THRESHHOLDING 1 u_short*
TIFFTAG_TILEDEPTH 1 u_long*
TIFFTAG_TILELENGTH 1 u_long*
TIFFTAG_TILEWIDTH 1 u_long*
TIFFTAG_XPOSITION 1 float*
TIFFTAG_XRESOLUTION 1 float*
TIFFTAG_YPOSITION 1 float*
TIFFTAG_YCBCRSAMPLING 1 u_short** 8 entry array
TIFFTAG_YRESOLUTION 1 float*
DIAGNOSTICS
All error messages are directed to the TIFFError(3T) routine.
Unknown field, tag 0x%x. An unknown tag was supplied.
SEE ALSO
intro(3T), TIFFOpen(3T), TIFFSetField(3T), TIFFSetDirectory(3T),
TIFFReadDirectory(3T), TIFFWriteDirectory(3T)
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