Changes in TIFF v3.5.7
======================

.. table:: References
  :widths: auto

  ======================  ==========================================
  Current Version         v3.5.7 (:tag:`Release-v3-5-7`)
  Previous Version        :doc:`v3.5.6beta <v3.5.6beta>`
  Master Download Site    `<https://download.osgeo.org/libtiff/>`_
  Master HTTP Site        `<http://www.simplesystems.org/libtiff/>`_
  ======================  ==========================================

This document describes the changes made to the software between the
*previous* and *current* versions (see above).
If you don't find something listed here, then it was not done in this
timeframe, or it was not considered important enough to be mentioned.
The following information is located here:


Software configuration changes
------------------------------

* :file:`libtiff/libtiff.def`: Brent Roman submitted new version adding
  several missing entry points.  Also add a few other entry points
  later.

* :file:`configure`, :file:`Makefile.in`, etc: added support for ``OPTIMIZER`` being
  set from :file:`config.site`.
* :file:`config.guess`: updated wholesale to an FSF version apparently
  from 1998 (as opposed to 1994).  This is mainly inspired by 
  providing for MacOS X support.

* :file:`configure/config.site`: modified to check if ``-lm`` is needed for
  ``MACHDEPLIBS`` if not supplied by :file:`config.site`.  Needed for Darwin.
* :file:`libtiff/tiff.h`: Applied hack to try and resolve the problem
  with the :file:`inttypes.h` include file on AIX. (bug :bugzilla-rs:`39`)

* :file:`configure`, :file:`*Makefile.in`: Various changes to improve configuration
  for HP/UX specifically, and also in general.  (bug :bugzilla-rs:`40`) They include:

   * Try to handle :program:`/usr/bin/sh` instead of :program:`/bin/sh` where necessary.
   * Upgrade to HP/UX 10.x+ compiler, linker and dso options.
   * Fixed :c:func:`mmap` test to avoid ``MMAP_FIXED`` ... it isn't available on HP
   * Use ``-${MAKEFLAGS}`` in sub makes from makefiles.
   * Fixed ``SCRIPT_SH``/``SHELL`` handling.

* :file:`configure`: Changes for DSO generation on AIX provided by
  `John Marquart <[email protected]>`_.

* :file:`configure`, :file:`libtiff/Makefile.in`: Modified to build DSOs properly
  on Darwin thanks to `Robert Krajewski <[email protected]>`_ and
  `Keisuke Fujii <[email protected]>`_.

* :file:`configure`, :file:`libtiff/Makefile.in`: applied OpenBSD patches as per bug :bugzilla-rs:`61`.

* :file:`Makefile.in`: added ``DESTDIR`` support as per bug :bugzilla-rs:`60`.

* :file:`libtiff/tif_jpeg.c`: Define :c:macro:`HAVE_BOOLEAN` on windows if :file:`RPCNDR.H`
  has been included.
* :file:`man/Makefile.in`: add :c:func:`TIFFClientOpen` link as per debian submitted
  bug :bugzilla-rs:`66`.
* :file:`libtiff/Makefile.in`: Fixed ``@DSOSUB_VERSION`` to be ``@DSOSUF_VERSION@``
  in two places.


Library changes
---------------

* :file:`tif_fax3.c`: keep :c:var:`rw_mode` flag internal to fax3 state to remember
  whether we are encoding or decoding.  This is to ensure graceful 
  recovery if :c:func:`TIFFClientOpen` discovers an attempt to open a compressed
  file for "``r+``" access, and subsequently close it, as it resets the
  :c:member:`tif_mode` flag to ``O_RDONLY`` in this case to avoid writes, confusing the
  compressor's concept of whether it is in encode or decode mode.

* :file:`tif_luv.c`, :file:`tiff.h`, :file:`tiffio.h`:
  New version of TIFF LogLuv (SGILOG) modules contributed by `Greg Ward
  <[email protected]>`_.  He writes:

  * I improved the gamut-mapping function in :file:`tif_luv.c` for imaginary
    colors, because some images were being super-saturated on the input
    side and this resulted in some strange color shifts in the output.

  * I added a psuedotag in :file:`tiff.h` to control random dithering during
    LogLuv encoding.  This is turned off by default for 32-bit LogLuv and
    on for 24-bit LogLuv output.  Dithering improves the average color
    accuracy over the image.

  * I added a ``#define`` for :c:macro:`LOG_LUV_PUBLIC`, which is enabled by default in
    :file:`tiffio.h`, to expose internal routines for converting between LogLuv and
    XYZ coordinates.  This is helpful for writing more efficient,
    specialized conversion routines, especially for reading LogLuv files.

* :file:`libtiff/tif_dirinfo.c`: don't declare :c:var:`tiffFieldInfo` static on VMS.

* Added :c:macro:`TIFFTAG_COPYRIGHT` support.

* :file:`tif_getimage.c`: Added support for 16bit minisblack/miniswhite
  images in RGBA interface.

* :file:`libtiff/tif_dirinfo.c`: removed duplicate :c:macro:`TIFFTAG_PHOTOSHOP` as per
  bug :bugzilla-rs:`44`.

* :file:`libtiff/tif_dirwrite.c`: Added support for :c:enumerator:`TIFF_VARIABLE2` in the
  case of writing :c:enumerator:`TIFF_BYTE`/:c:enumerator:`TIFF_SBYTE` fields as per
  bug :bugzilla-rs:`43`.

* :file:`libtiff/tif_dirinfo.c`: Modified the :c:enumerator:`TIFF_BYTE` definition for
  :c:macro:`TIFFTAG_PHOTOSHOP` to use a writecount of :c:enumerator:`TIFF_VARIABLE2` (-3) to
  force use of :c:type:`uint32` counts instead of :c:expr:`short` counts.

* :file:`libtiff/tif_dirinfo.c`: moved pixar and copyright flags to ensure everything is in order.

* Integrated experimental OJPEG support from Scott Marovich of HP.  

* :file:`libtiff/tif_open.c`: Seek back to zero after failed read, before writing header.

* :file:`libtiff/tiff.h`, :file:`libtiff/tif_fax3.c`: added check for :c:macro:`__LP64__`
  when checking for 64 bit architectures as per bugzilla bug :bugzilla-rs:`67`.

* :file:`libtiff/tif_getimage.c`: Use :c:func:`memmove` instead of :c:func:`TIFFmemcpy`
  in :c:func:`TIFFReadRGBATile` to avoid issues in cases of overlapping
  buffers.  See bug :bugzilla-rs:`69` in Bugzilla.

* :file:`libtiff/tif_getimage.c`: Don't complain for CMYK (separated)
  images with more than four samples per pixel as per bug :bugzilla-rs:`73`.

* :file:`libtiff/tif_getimage.c`: relax handling of contig case where
  there are extra samples that are supposed to be ignored as per bug :bugzilla-rs:`75`.  This
  should now work for 8bit greyscale or paletted images.

* :file:`libtiff/tif_packbits.c`: fixed memory overrun error as per bug :bugzilla-rs:`77`.

* :file:`libtiff/tif_getimage.c`: Fixed problem with reading strips or
  tiles that don't start on a tile boundary.  Fix contributed by
  Josep Vallverdu (from HP), and further described in bug :bugzilla-rs:`47`.

* :file:`libtif/tif_fax3.c`: Removed ``#ifdef PURIFY`` logic, and modified to
  always use the "safe" version, even if there is a very slight
  cost in performance as per bug :bugzilla-rs:`54`.

* :file:`libtiff/tif_lzw.c`: added dummy :c:func:`LZWSetupEncode` to report an
  error about LZW not being available.

* :file:`libtiff/tif_dir.c`: propagate failure to initialize compression
  back from :c:func:`TIFFSetField` as an error status, so applications can
  detect failure.

* :file:`libtiff/tif_lzw.c`: Avoid MS VC++ 5.0 optimization bug as per bug :bugzilla-rs:`78`.

* :file:`libtiff/tif_dirwrite.c`: added :c:func:`TIFFRewriteDirectory` function.
  Updated :c:func:`TIFFWriteDirectory` man page to include :c:func:`TIFFRewriteDirectory`.

* :file:`libtiff/tiff.h`: I have created :c:macro:`COMPRESSION_CCITT_T4`,
  :c:macro:`COMPRESSION_CCITT_T6`, :c:macro:`TIFFTAG_T4OPTIONS` and :c:macro:`TIFFTAG_T6OPTIONS` aliases
  in keeping with TIFF 6.0 standard in :file:`tiff.h` as per bug :bugzilla-rs:`83`.

* Added :c:macro:`PHOTOMETRIC_ITULAB` as per bug :bugzilla-rs:`90`.


Tools changes
-------------

* Brent Roman contributed updated :program:`tiffcp` utility (and :file:`tiffcp.1`)
  with support for extracting subimages with the ``,n`` syntax, and also
  adding the "``-b``" bias removal flag.

* :file:`tiff2ps.c`, :file:`tiff2ps.1`: Substantial changes to :program:`tiff2ps` by
  Bruce A. Mallett, including a faster encoder, fixes for level
  2 PostScript, and support for the imagemask operator.

* fax2ps.c: Helge (libtiff at oldach.net) submitted fix
  that corrects behaviour for non-Letter paper
  sizes. (bug :bugzilla-rs:`35`) It fixes two problems:

  Without  scaling ("``-S``") the fax is now centered on the page size specified
  with "``-H``" and/or "``-W``". Before, :program:`fax2ps` was using an obscure and practically
  useless algorithm to allocate the image relative to Letter sized paper
  which sometime sled to useless whitespace on the paper, while at the
  same time cutting of the faxes printable area at the opposite border.

  Second, scaling now preserves aspect ratio, which makes unusual faxes
  (in particular short ones) print properly.

* :file:`thumbnail.c`: changed default output compression
  to packbits from LZW since LZW isn't generally available.

* :file:`tiff2rgba.c`: added "``-n``" flag to avoid emitting alpha component. Also added
  a man page for :program:`tiff2rgba`.

* :file:`tiffcmp.c`: Fixed multi samples per pixel support for :c:func:`ContigCompare`
  as per bug :bugzilla-rs:`53`.
  Updated bug section of tiffcmp.1 to note tiled file issues.

* :file:`libtiff/tif_getimage.c`: Fixed so that failure is properly
  reported by :c:func:`gtTileContig`, :c:func:`gtStripContig`, :c:func:`gtTileSeparate` and
  :c:func:`gtStripSeparate` as per bug :bugzilla-rs:`51`.


Contributed software changes
----------------------------

* Fixed distribution to include :file:`contrib/addtiffo/tif_ovrcache.c`
  and :file:`contrib/addtiffo/tif_ovrcache.h`.


LZW compression kit changes
---------------------------

* Rewrote lzw patching process so that is required to enable full
  LZW support is to drop the :file:`tif_lzw.c` from the
  ``libtiff-lzw-compression-kit`` over the one in the libtiff directory.

* Some changes were made to make recovery from failure to
  initialize the LZW compressor more graceful.

* Note that as distributed libtiff support LZW decompression, but
  not LZW compression.