tiffgetfield(3)

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 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.) The file
must have been previously opened with TIFFOpen(3). 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 vari
able argument list as prescribed by the stdarg(3) inter
face. 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 by TIFFGetField.

TIFFGetFieldDefaulted and TIFFVGetFieldDefaulted are iden tical 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, the number of parameter values, and the types for the returned values are shown
below. The data types are specified as in C and corre
spond to the types used to specify tag values to TIFFSet_ Field(3). Remember that TIFFGetField returns parameter values, so all the listed data types are pointers to stor
age 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_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 u_short*,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.

RETURN VALUES

1 is returned if the tag is defined in the current direc
tory; otherwise a 0 is returned.

DIAGNOSTICS

All error messages are directed to the TIFFError(3) rou tine.

Unknown field, tag 0x%x. An unknown tag was supplied.

docs.sk

comprehensive documentation repository

In section