Provided by: libtiff-dev_4.0.10+git191003-1_amd64 bug

NAME

       TIFFOpen, TIFFFdOpen, TIFFClientOpen - open a TIFF file for reading or writing

SYNOPSIS

       #include <tiffio.h>

       TIFF* TIFFOpen(const char *filename, const char *mode)
       TIFF* TIFFFdOpen(const int fd, const char *filename, const char *mode)

       typedef tsize_t (*TIFFReadWriteProc)(thandle_t, tdata_t, tsize_t);
       typedef toff_t (*TIFFSeekProc)(thandle_t, toff_t, int);
       typedef int (*TIFFCloseProc)(thandle_t);
       typedef toff_t (*TIFFSizeProc)(thandle_t);
       typedef int (*TIFFMapFileProc)(thandle_t, tdata_t*, toff_t*);
       typedef void (*TIFFUnmapFileProc)(thandle_t, tdata_t, toff_t);

       TIFF*  TIFFClientOpen(const  char  *filename,  const  char  *mode,  thandle_t  clientdata,
       TIFFReadWriteProc   readproc,   TIFFReadWriteProc   writeproc,   TIFFSeekProc    seekproc,
       TIFFCloseProc closeproc, TIFFSizeProc sizeproc, TIFFMapFileProc mapproc, TIFFUnmapFileProc
       unmapproc)

DESCRIPTION

       TIFFOpen opens a TIFF file whose name is filename and returns  a  handle  to  be  used  in
       subsequent  calls  to  routines  in  libtiff.   If  the open operation fails, then zero is
       returned.  The mode parameter specifies if the file is to be opened for  reading  (``r''),
       writing (``w''), or appending (``a'') and, optionally, whether to override certain default
       aspects of library operation (see below).  When a file is opened for  appending,  existing
       data  will not be touched; instead new data will be written as additional subfiles.  If an
       existing file is opened for writing, all previous data is overwritten.

       If a file is opened for reading, the first TIFF directory in  the  file  is  automatically
       read  (also see TIFFSetDirectory(3TIFF) for reading directories other than the first).  If
       a file is opened for writing or appending, a default directory  is  automatically  created
       for  writing subsequent data.  This directory has all the default values specified in TIFF
       Revision  6.0:  BitsPerSample=1,  ThreshHolding=bilevel  art   scan,   FillOrder=1   (most
       significant  bit of each data byte is filled first), Orientation=1 (the 0th row represents
       the visual top of the image, and the 0th column represents the  visual  left  hand  side),
       SamplesPerPixel=1, RowsPerStrip=infinity, ResolutionUnit=2 (inches), and Compression=1 (no
       compression).  To  alter  these  values,  or  to  define  values  for  additional  fields,
       TIFFSetField(3TIFF) must be used.

       TIFFFdOpen is like TIFFOpen except that it opens a TIFF file given an open file descriptor
       fd.  The file's name and mode must reflect  that  of  the  open  descriptor.   The  object
       associated with the file descriptor must support random access.

       TIFFClientOpen  is like TIFFOpen except that the caller supplies a collection of functions
       that the library will use to do UNIX-like I/O operations.  The readproc and writeproc  are
       called  to read and write data at the current file position.  seekproc is called to change
       the current file position a la lseek(2).  closeproc is invoked to  release  any  resources
       associated  with an open file.  sizeproc is invoked to obtain the size in bytes of a file.
       mapproc and unmapproc are called to map and  unmap  a  file's  contents  in  memory;  c.f.
       mmap(2)  and  munmap(2).   The  clientdata parameter is an opaque ``handle'' passed to the
       client-specified routines passed as parameters to TIFFClientOpen.

OPTIONS

       The open mode parameter can include the following flags in addition to the  ``r'',  ``w'',
       and  ``a''  flags.   Note  however  that  option  flags  must follow the read-write-append
       specification.

       l      When creating a new file force information be written with Little-Endian byte order
              (but see below).  By default the library will create new files using the native CPU
              byte order.

       b      When creating a new file force information be written with  Big-Endian  byte  order
              (but see below).  By default the library will create new files using the native CPU
              byte order.

       L      Force image data that is read or written to be treated with bits filled from  Least
              Significant  Bit  (LSB)  to  Most  Significant  Bit  (MSB).   Note that this is the
              opposite to the way the library has worked from its inception.

       B      Force image data that is read or written to be treated with bits filled  from  Most
              Significant Bit (MSB) to Least Significant Bit (LSB); this is the default.

       H      Force image data that is read or written to be treated with bits filled in the same
              order as the native CPU.

       M      Enable the use  of  memory-mapped  files  for  images  opened  read-only.   If  the
              underlying  system  does  not  support memory-mapped files or if the specific image
              being opened cannot be memory-mapped then the library will fallback  to  using  the
              normal  system  interface  for  reading  information.   By default the library will
              attempt to use memory-mapped files.

       m      Disable the use of memory-mapped files.

       C      Enable the use of ``strip chopping'' when reading images that are  comprised  of  a
              single  strip or tile of uncompressed data.  Strip chopping is a mechanism by which
              the library will automatically convert the single-strip image to  multiple  strips,
              each  of  which  has  about  8  Kilobytes  of data.  This facility can be useful in
              reducing the amount of memory used to read an image because  the  library  normally
              reads  each  strip in its entirety.  Strip chopping does however alter the apparent
              contents of the image because when an image is  divided  into  multiple  strips  it
              looks  as  though  the underlying file contains multiple separate strips.  Finally,
              note that default handling  of  strip  chopping  is  a  compile-time  configuration
              parameter.   The default behaviour, for backwards compatibility, is to enable strip
              chopping.

       c      Disable the use of strip chopping when reading images.

       h      Read TIFF header only, do not load the first image directory. That could be  useful
              in  case  of  the  broken  first directory. We can open the file and proceed to the
              other directories.

       4      ClassicTIFF for creating a file (default)

       8      BigTIFF for creating a file.

       D      Enable use of deferred strip/tile offset/bytecount  array  loading.  They  will  be
              loaded  the  first  time  they  are  accessed  to. This loading will be done in its
              entirety unless the O flag is also specified.

       O      On-demand loading of values of the strip/tile offset/bytecount arrays,  limited  to
              the requested strip/tile, instead of whole array loading (implies D)

BYTE ORDER

       The  TIFF  specification  (all  versions) states that compliant readers must be capable of
       reading images written in either byte order.  Nonetheless some  software  that  claims  to
       support  the  reading  of  TIFF  images is incapable of reading images in anything but the
       native CPU byte order on which  the  software  was  written.   (Especially  notorious  are
       applications  written to run on Intel-based machines.)  By default the library will create
       new files with the native byte-order of the CPU on which the  application  is  run.   This
       ensures  optimal  performance and is portable to any application that conforms to the TIFF
       specification.  To force the library to use a specific byte-order when creating a new file
       the  ``b'' and ``l'' option flags may be included in the call to open a file; for example,
       ``wb'' or ``wl''.

RETURN VALUES

       Upon successful completion TIFFOpen, TIFFFdOpen, and TIFFClientOpen return a TIFF pointer.
       Otherwise, NULL is returned.

DIAGNOSTICS

       All  error  messages  are  directed  to  the  TIFFError(3TIFF) routine.  Likewise, warning
       messages are directed to the TIFFWarning(3TIFF) routine.

       "%s": Bad mode.  The specified mode parameter was not one of ``r'' (read), ``w''  (write),
       or ``a'' (append).

       %s: Cannot open.  TIFFOpen() was unable to open the specified filename for read/writing.

       Cannot  read  TIFF  header.   An  error  occurred  while  attempting  to  read  the header
       information.

       Error writing TIFF header.  An error occurred while writing the default header information
       for a new file.

       Not a TIFF file, bad magic number %d (0x%x).  The magic number in the header was not (hex)
       0x4d4d or (hex) 0x4949.

       Not a TIFF file, bad version number %d (0x%x).  The version field in the header was not 42
       (decimal).

       Cannot  append  to  file  that  has  opposite  byte ordering.  A file with a byte ordering
       opposite to the native byte ordering of the  current  machine  was  opened  for  appending
       (``a'').  This is a limitation of the library.

SEE ALSO

       libtiff(3TIFF), TIFFClose(3TIFF)