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TIFFGetField(3TIFF)                                        TIFFGetField(3TIFF)

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  li-
       brary  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  re-
       turned  is dependent on the tag being requested. The programming inter-
       face uses a variable argument list as prescribed by the  stdarg(3)  in-
       terface. 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  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 pa-
       rameter values, so all the listed data types are  pointers  to  storage
       where  values  should  be returned.  Consult the TIFF specification (or
       relevant industry specification) for information on the meaning of each
       tag and their possible values.

       Tag Name                        Count  Types             Notes
       TIFFTAG_ARTIST                  1      const char**
       TIFFTAG_BADFAXLINES             1      uint32_t*
       TIFFTAG_BITSPERSAMPLE           1      uint16_t*
       TIFFTAG_CLEANFAXDATA            1      uint16_t*
       TIFFTAG_COLORMAP                3      const uint16_t**  1<<BitsPerSample arrays
       TIFFTAG_COMPRESSION             1      uint16_t*
       TIFFTAG_CONSECUTIVEBADFAXLINES  1      uint32_t*
       TIFFTAG_COPYRIGHT               1      const char**
       TIFFTAG_DATATYPE                1      uint16_t*
       TIFFTAG_DATETIME                1      const char**
       TIFFTAG_DOCUMENTNAME            1      const char**
       TIFFTAG_DOTRANGE                2      uint16_t*
       TIFFTAG_EXTRASAMPLES            2      uint16_t*,const uint16_t**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_t*
       TIFFTAG_GROUP3OPTIONS           1      uint32_t*
       TIFFTAG_GROUP4OPTIONS           1      uint32_t*
       TIFFTAG_HALFTONEHINTS           2      uint16_t*
       TIFFTAG_HOSTCOMPUTER            1      const char**
       TIFFTAG_ICCPROFILE              2      const uint32_t*,const void**count, profile data
       TIFFTAG_IMAGEDEPTH              1      uint32_t*
       TIFFTAG_IMAGEDESCRIPTION        1      const char**
       TIFFTAG_IMAGELENGTH             1      uint32_t*
       TIFFTAG_IMAGEWIDTH              1      uint32_t*
       TIFFTAG_INKNAMES                1      const char**
       TIFFTAG_INKSET                  1      uint16_t*
       TIFFTAG_JPEGCOLORMODE           1      int*              JPEG pseudo-tag
       TIFFTAG_JPEGQUALITY             1      int*              JPEG pseudo-tag
       TIFFTAG_JPEGTABLES              2      uint32_t*,const void**count & tables
       TIFFTAG_JPEGTABLESMODE          1      int*              JPEG pseudo-tag
       TIFFTAG_MAKE                    1      const char**
       TIFFTAG_MATTEING                1      uint16_t*
       TIFFTAG_MAXSAMPLEVALUE          1      uint16_t*
       TIFFTAG_MINSAMPLEVALUE          1      uint16_t*
       TIFFTAG_MODEL                   1      const char**
       TIFFTAG_ORIENTATION             1      uint16_t*
       TIFFTAG_PAGENAME                1      const char**
       TIFFTAG_PAGENUMBER              2      uint16_t*
       TIFFTAG_PHOTOMETRIC             1      uint16_t*
       TIFFTAG_PHOTOSHOP               2      uint32_t*,const void**count, data
       TIFFTAG_PLANARCONFIG            1      uint16_t*
       TIFFTAG_PREDICTOR               1      uint16_t*
       TIFFTAG_PRIMARYCHROMATICITIES   1      const float**     6-entry array
       TIFFTAG_REFERENCEBLACKWHITE     1      const float**     6-entry array
       TIFFTAG_RESOLUTIONUNIT          1      uint16_t*
       TIFFTAG_RICHTIFFIPTC            2      uint32_t*,const void**count, data
       TIFFTAG_ROWSPERSTRIP            1      uint32_t*
       TIFFTAG_SAMPLEFORMAT            1      uint16_t*
       TIFFTAG_SAMPLESPERPIXEL         1      uint16_t*
       TIFFTAG_SMAXSAMPLEVALUE         1      double*
       TIFFTAG_SMINSAMPLEVALUE         1      double*
       TIFFTAG_SOFTWARE                1      const char**
       TIFFTAG_STONITS                 1      const double**
       TIFFTAG_STRIPBYTECOUNTS         1      const uint64_t**
       TIFFTAG_STRIPOFFSETS            1      const uint64_t**
       TIFFTAG_SUBFILETYPE             1      uint32_t*
       TIFFTAG_SUBIFD                  2      uint16_t*,const uint64_t**count & offsets array
       TIFFTAG_TARGETPRINTER           1      const char**
       TIFFTAG_THRESHHOLDING           1      uint16_t*
       TIFFTAG_TILEBYTECOUNTS          1      const uint64_t**
       TIFFTAG_TILEDEPTH               1      uint32_t*
       TIFFTAG_TILELENGTH              1      uint32_t*
       TIFFTAG_TILEOFFSETS             1      const uint64_t**
       TIFFTAG_TILEWIDTH               1      uint32_t*
       TIFFTAG_TRANSFERFUNCTION        1 or 3†                  const uint16_t**1<<BitsPerSample entry arrays
       TIFFTAG_WHITEPOINT              1      const float**     2-entry array
       TIFFTAG_XMLPACKET               2      uint32_t*,const void**count, data
       TIFFTAG_XPOSITION               1      float*
       TIFFTAG_XRESOLUTION             1      float*
       TIFFTAG_YCBCRCOEFFICIENTS       1      const float**     3-entry array
       TIFFTAG_YCBCRPOSITIONING        1      uint16_t*
       TIFFTAG_YCBCRSUBSAMPLING        2      uint16_t*
       TIFFTAG_YPOSITION               1      float*
       TIFFTAG_YRESOLUTION             1      float*‡
       † 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 an  un-
       supported  tag and is not directly supported by 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:

              uint32_t  count;
              void    *data;

              TIFFGetField(tiff, 33424, &count, &data);
              printf("Tag %d: %d, count %d0, 33424, *(uint32_t *)data, count);
              TIFFGetField(tiff, 36867, &count, &data);
              printf("Tag %d: %s, count %d0, 36867, (char *)data, count);

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
       TIFFOpen(3TIFF),  TIFFSetField(3TIFF),  TIFFSetDirectory(3TIFF),  TIFF-
       ReadDirectory(3TIFF), TIFFWriteDirectory(3TIFF) libtiff(3TIFF),

       Libtiff library home page: http://www.simplesystems.org/libtiff/

libtiff                         March 29, 2020             TIFFGetField(3TIFF)

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