22/03/2016: Version 1.0 Released


08/03/2016:
	- Added sizes field to IIIF JSON responses giving list of exportable pyramid sizes
	  smaller than MAX_CVT.


29/02/2016:
	- Added support for 1 bit bilevel TIFF


11/02/2016:
	- Added backlog parameter support for command line use through --backlog parameter.
	- Fixed several more Coverity scan warnings.


29/01/2016:
	- Minor update to IIPImage.cc to reduce risk of race condition in stat -> fopen calls


28/01/2016:
	- Added ifdefs to Transform.cc to enforce either ivdep for icc or openmp for gcc


15/01/2016:
	- Fixed a series of minor issues identified by Coverity scan


12/01/2016:
	- Added check to JPEGCompressor to reject images that are not 8 bits per channel
	- Added new floatProcessing() function to View.h to simplify code in JTL and CVT


06/01/2016:
	- Added extra parameter check for incoherent region sizes for IIIF protocol


21/12/2015:
	- Fixed infinite loop in View::calculateResolution if requested size = 0. Set
	  minimum output size to 1px.


07/09/2015:
	- Fixed isfinite autoconf macro in acinclude.m4 to force float type


06/08/2015:
	- Added timestamp check and metadata reload for images that have been modified
	- Added X-Powered-By header as a number of web servers strip out the Server header


03/08/2015:
	- Added palette support for bilevel images to handle cases where LUTs are inverted


27/07/2015:
	- Modified ROT command to accept horizontal flipping through "!" prefix as with IIIF.
	- Cosmetic improvement to FIF logging.
	- Modified TPTImage to disable use of memory mapping when opening images as this seems
	  to be slower when opening very large TIFFs.


24/07/2015:
	- Added timers to all image processing functions in CVT.cc + code cleanup.


21/07/2015:
	- Fixed error in View.cc when setting regions sizes that extend beyond image boundaries:
	  regions now cropped to boundaries.


20/07/2015:
	- More OpenMP parallelization and cleanups to Transform.cc


17/07/2015:
	- Increased buffer memory for JPEG encoding to handle certain images or tiles that
	  encode at Q=100 to sizes significantly larger than the raw data.
	- Added new CACHE_CONTROL server parameter to allow user control over this. If not
	  set, it defaults to the previous default value of "max-age=86400".
	- More image processing routines now parallelized with OpenMP: bilinear interpolation,
	  for example, now parallelized and considerably faster.


19/03/2015:
	- Fix to KakaduImage.cc to check for increases in stripe heights and make sure
	  sufficient memory is allocated.


13/02/2015:
	- Added checks for NULL FCGX_GetParam results and to empty HTTP_IF_MODIFIED_SINCE.
	  See: https://github.com/ruven/iipsrv/issues/33 - thanks to Brian Helba.


12/02/2015:
	- Fixed @id decoding in IIIF.cc for paths containing slashes


19/01/2015:
	- Added missing <cctype> include in URL.h and replaced pow(2.0,x) with bit shifting in
	  KakaduImage.cc and View.cc. Now compiles cleanly with VisualStudio Express.
	- Added extra OpenMP parallel declarations to Transform.cc and autoconf directive to
	  enable OpenMP by default.


09/01/2015:
	- Better logging for exceptions in Main.cc


27/11/2014:
	- Added new magic identifier for BigTIFF images to IIPImage.cc


25/11/2014:
	- Fix of rounding error problem in View.cc for calculating resolution level.
	- Fix to IIIF.cc to properly handle resolution 0 requests.


24/11/2014:
	- Fix to TileManager.cc to properly calculate tile height for final row.
	- Updates to IIIF code to ensure tiles are properly detected.
	- Changes to View class to calculate regions from full resolution image.


24/10/2014:
	- Updated MINMAX command syntax in Task.cc to channel:min,max


22/10/2014:
	- Updated KakaduImage.cc to use Kakadu namespaces in version 7.5 and greater.


05/09/2014:
	- Updated IIIF info.json output to be compliant with changed IIIF 2.0 specification.


03/09/2014:
	- Fix to IIPImage.cc for file type detection for multispectral sequences.


22/08/2014:
	- Fix to properly read 12 bit JP2 files.
	- KakaduImage's virtual_levels counter moved into IIPImage class.
	- Modification to properly read number of components in multi-band JPEG2000 images.


21/08/2014:
	- Fixes to allow compilation on older versions of gcc.


20/08/2014:
	- Cleanup to IIIF code and some cosmetic improvements to generated JSON.
	- Added string escape function to URL class and moved all environment variable access to
	  Main.cc.


19/08/2014:
	- Added aspect ratio flag in View.h for use in CVT.cc. Also cleaned up Main.cc to remove
	  unnecessary logging and record extra http headers.
	- Added IIIF protocol version 2.0 support via the IIIF argument.


13/08/2014:
	- The rotate filter only ever operates on 8bit data, so remove if else type statements from
	  function - increases average function speed by about around 15%.
	- Added missing URL.h to src/Makefile.am.
	- Refactored JTL into 2 separate functions: run (parses arguments) & send (performs tile
	  request, processing and sending). Allows this to be re-used in other functions, such as
	  Zoomify.cc etc.
	- Refactored CVT similarly to JTL with now a separate send() function.


11/08/2014:
	- Renamed variable bpp in IIPImage and its derived classes to bpc (bits per channel),
	  which is more logical and how we have named things elsewhere.
	- Modification to TileManager, which was requesting more tiles than necessary for regions.
	- Changes to View.cc to make WID and HEI requests with region exports produce images with a
	  *final* size of that requested by WID or HEI. For example RGN=0.1,0.1,0.5,0.5&WID=500 will
	  now produce an image of 500px in width rather than extract the region from an image of size
	  500px wide. CVT also cleaned up.


06/08/2014:
	- Updated exception handling to use std::invalid_argument and a new derived file_error
	  exception within the IIPImage and derived classes. Allows better distinguishing between
	  HTTP status errors.
	- Moved URL decoding code from FIF.cc to separate URL class in URL.h.


05/08/2014:
	- Added flip function to Transforms.
	- Modified JTL, DeepZoom, Zoomify and CVT to avoid float conversion if not required.
	- Converted bilinear and nearest neighbour resize code to unsigned char to avoid
	  unnecessary conversion to float.


30/07/2014:
	- Moved CTW processing function to before gamma function in JTL.cc and CVT.cc.
	- Added missing function comments and minor layout changes in Transform.cc and FIF.cc.


24/07/2014:
	- Simplified the use of hash_map types and removed the customized hash function, which
	  was causing our image metadata cache to work incorrectly. Removed the const prefix from
	  all hash maps keys.


20/07/2014:
	- Min Max values are now read as vectors in multiple channel images - thanks to Chiara Marmo.


19/07/2014:
	- Added support for magic byte signature file format detection instead of relying on
	  the file path suffix. Images can now be named arbitrarily (though suffixes still used
	  for sequences). Format enum types added to IIPImage class.


18/07/2014:
	- Fix for unusual JPEG2000 "sRGB" bilevel images.


20/03/2014:
	- Fixed signed/unsigned comparison compiler warning in Task.cc.


16/03/2014:
	- Added back missing <algorithm> include to Task.cc.


12/03/2014:
	- Added ability to handle multi-band (>3 channel) images and added new CTW color twist
	  command that takes a matrix that is applied to each channel in the image.
	- Cleanup of and more comprehensive timing output within JTL.cc.


08/03/2014:
	- Changes to resizing algorithms to enable expansions as well as shrink for all views
	  and regions.
	- Added CORS (Cross Origin Resource Sharing) support via CORS environment variable for
	  (AJAX) metadata requests.


24/02/2014:
	- Added missing function timer to JTL.cc and increased output precision in PFL.cc to 9.


24/01/2014:
	- Changes to IIPImage and KakaduImage constructors to force correct initialization of
	  the tile size.
	- Added missing std::isinfinite function for Windows Visual Studio compilation.


17/01/2013:
	- Fix to rotation code to have array indices run fully down to zero when counting down.
	  Thanks to Michal Becak for spotting this.


06/12/2013:
	- Minor fixes to PFL.cc to add extra error checking and eliminate compiler warnings.


05/12/2013:
	- Another update to use the ISO C++11 version of unordered_map if available. Plus a bunch
	  of compiler warning clean-ups.


04/12/2013:
	- Updated hash map definitions to try to use unordered_map if available and fall back to
	  hash_map or map. Now done more cleanly using autoconf detection.


02/12/2013:
	- Changes to IIPImage, TPTImage and KakaduImage class contstructors to use more efficient
	  member initializer lists, which are also necessary for compilation with clang compiler.


25/11/2013:
	- Bug on red/green/blue colormaps fixed. Adding colormap inversion function (Chiara Marmo).


22/10/2013:
	- Bittype compatibility has been completely reviewed. After normalization all processing
	  is done in float (Chiara Marmo).


07/09/2013:
	- Modified PFL to handle single points as well as profiles. Thus syntax for single
	  points: PFL=<resolution>:<x>,<y> and for profiles PFL=<resolution>:<x1>,<y1>-<x2>,<y2>


03/09/2013:
	- Updated PFL command to also handle multi-spectral data.


02/09/2013:
	- Modified PFL command to use JSON and implemented vertical profiles.


28/08/2013:
	- Added PFL command for obtaining raw X profiles of data. Syntax
	  is <resolution>:<x1>,<y1>-<x2>,<y2>. Only horizontal profiles are supported so far.


23/08/2013:
	- Fix to OpenMP code in Transform.cc for compatibility with Intel compiler - thanks
	  Emmanuel Bertin.
	- Addition of extra timing output in JTL.cc


06/08/2013:
	- Moved setenv/unsetenv function definitions to Main.cc where they are now needed following
	  movement of timezone setting code there.


31/07/2013:
	- Fix to JTL.cc and TPTImage.cc for multispectral sequences consisting of images of
	  different bit depths.


23/07/2013:
	- Fix to KakaduImage.cc to enable correct handling of bilevel images.
	- Fix to quality layer decoding - variables moved directly into IIPImage class
	- Scaling of 8 and 16 bit spectral data to normalized 0.0->1.0 float in SPECTRA.cc


08/07/2013:
	- Fix to configure.in for libmemcached configuration problem on Fedora.


02/07/2013:
        - Optimizations to FIF.cc. Unnecessary file header reading is now avoided as top
          level IIPImage class cache fully utilized. Cleanup of constructor code of IIPImage,
          TPTImage and KakaduImage code. Significant speed up to requests of cached images.
        - Modification to if_modified_since code in FIF.cc, to avoid repeatedly resetting the
          timezone environment variable to UTC when checking timestamps, which is a relatively
          slow process. This is now set once globally in Main.cc and set back on main exit.


12/06/2013:
	- Extra checks for malformed images in KakaduImage.cc.


11/04/2013:
	- Several fixes to Kakadu.cc. To force resolution levels to be floor(x/2) rather than the default
	  ceil(x/2) to match how TIFF resolutions are created. Also modification to force 16 bit
	  JPEG2000 to unsigned output. And also fix to strip alpha channels from images.


14/03/2013:
	- Fix to gamma conversion - thanks Chiara Marmo
	- Update to greyscale conversion code


09/03/2013:
	- Updated copyright message in header to new Free Software Foundation address.


08/03/2013:
	- Added greyscale conversion support via new filter_greyscale transform function.


23/02/2013:
	- Gamma correction fixed, minmax commands added, colormap commands added (Chiara Marmo)


30/01/2013:
	- Fix to prevent crashing on malformed JPEG2000 files.


11/12/2012:
	- Changed FLOAT enum type to FLOATINGPOINT to avoid VC++ compiler error.
	- Implemented 16 and 32bit versions of interpolation functions.


10/12/2012:
	- Cleanup to 32 bit code
	- New command to set dynamically the min and max for 32 bit float
	- Addition of rotation function for 90,180,270 degree rotations
	- Fixes to autoconf


30/10/2012:
	- Autoconf cleanup. Removed unnecessary autoconf files: should now use
	  autogen.sh script first before ./configure


18/10/2012:
	- Fix to imageCache delete in FIF.cc - thanks to Michal Becak.


16/10/2012:
	- Added support for TIFF 32 bit integer and float.
	- Fixed 16 bit JPEG2000 support.
	- Added 1 bit support for TIFF.
	- Added gamma support via GAM command.
	- Thanks to Chiara Marmo for initial implementation.


09/09/2012:
	- TIFF metadata fixes.


25/08/2012:
	- Windows compilation fixes by Michal Becak.


13/08/2012:
	- Detect JPEG YCbCr encoding in TIFF and request conversion to RGB
	  by libtiff. Tile _TIFFmalloc() now only occurs in getTile().


16/07/2012:
	- Added check to KakaduImage.cc to handle bilevel images.
	- Clean up to use only floats and floorf() in Transforms.cc.


14/05/2012:
	- Added bilinear interpolation option for CVT resizing. Added
	  INTERPOLATION parameter to Environment.h, which takes an integer.
	  0 for fastest nearest neighbour and 1 for bilinear (default).
	  Current bilinear implementation 2.5x slower than nearest neighbour.
	- Additional fix to MAX_LAYERS code.


11/05/2012:
	- Modified layer handling to decode all available layers if
	  MAX_LAYERS parameter is set to -1.


08/05/2012:
	- Fix to Mac OSX and FreeBSD compilation of KakaduImage.cc.


07/05/2012:
	- Fixed strip height calculation error in CVT.cc


01/05/2012:
	- Modified memory handling in JPEGCompressor.cc to better handle
	  images where the compressed version may be bigger than the
	  original (for example at very high quality levels).
	- Changes to CVT.cc to work with new JPEGCompressor code and removal
	  of chunked encoding header directive from CVT.cc.
	- Fixed bug in CVT when specifying both WID and HEI.
	- Fixed compiler warning in IIPResponse.cc.
	- Added man page.
	- Added missing definition of get_nprocs() function to Kakadu.cc
	  for Mac OSX and FreeBSD.


20/04/2012:
	- Fixed memory overun error in filter_contrast in Transforms.cc.


18/04/2012:
	- Major rewrite of CVT code to unify TIFF and JPEG2000 region
	  export. Region compositing now in TileManager->getRegion with
	  modified getRegion Kakadu function. Changes also to View class
	  and ColourTransforms code to enable greater modularity for
	  image processing to regions. ColourTransforms renamed to
	  Transforms.
	  Thanks to The National Library of Wales, who will be using
	  iipsrv & iipmooviewer to deliver their Historic Newspapers
	  in 2012.


21/03/2012:
	- Fix to TPTImage.c to force RGB conversion for YCbCr compressed
	  JPEG TIFFs, which is now the default in VIPS. Thanks to John
	  Cupitt for spotting this.


17/03/2012:
	- Changes to View.[h,cc] to make sure getRequestWidth and Height
	  return correctly rounded values.


12/03/2012:
	- Added HTTP Status: 400 Bad Request to error messages.


28/01/2012:
	- Fixes to KakaduImage.cc to properly catch exceptions during file
	  opening and a check for existence during codestream shutdown.
	- Also added a check to updateTimeStamp to throw an exception if file
	  unreadable.


28/08/2011:
	- Performance improvement to JPEG2000 16->8 bit downsampling. Now
	  using integer arithmetic rather than float.


24/08/2011:
	- Updates to configure.in, FIF.cc and DeepZoom.cc to check for and
	  handle missing setenv, unsetenv and log2 functions. Fixes problem
	  on Solaris 10.


02/08/2011:
	- Changed timegm function in FIF.cc to use more cross-platform POSIX
	  mktime function instead. Fixes compilation error on Solaris.


22/07/2011:
	- Added 16bit and CIELAB support for JPEG2000.
	- Other minor cleanups.


24/05/2011:
	- Fix added to DeepZoom.cc as FreeBSD does not have the log2 function.
	  Thanks to Andrew Hankinson for spotting this.


23/05/2011:
	- Another fix to ensure the max layers variable is correctly used in
	  Zoomify and DeepZoom output.


15/04/2011: Version 0.9.9 Released


15/04/2011:
	- Fix to View.h to properly take into account max layers variable.


14/04/2011:
	- Minor logging update to Zoomify.cc.


13/04/2011:
	- Updated VC++ project files.
	- Minor changes to logging in Main.cc.
	- Updated autoconf files.


08/04/2011:
	- Change to TileManager.cc to take into account whether a tile is padded
	  or not when applying a watermark.


06/04/2011:
	- Changes to allow compilation on Windows with Visual C++ Express 2010.
	  New windows subfolder with missing time definitions and VC solution file.
	  Fixes also include definition of snprintf, log2 and S_ISREG, which are
	  all missing in Windows. Many thanks to Rob "Bubba" Hines for his help in
	  porting.


21/03/2011:
	- Added extra NULL assignment to Task pointer after catch block to avoid
	  problems with uninitialized memory being deleted.
	- Added SIGINT handler for Ctrl-C interruptions with strsignal() to
	  display a more meaningful message.


17/03/2011:
	- Clean-up of signed/unsigned variables in IIPImage.h and KakaduImage.h.


15/03/2011:
	- Added sanity check for requested resolutions and tiles in JTL.cc.
	- Fixed problem with edge tiles and watermarking.
	- Clean-up of error message in TPTImage.cc.


14/03/2011:
	- Fixed problem with standalone mode. Can now bind to an FCGI socket by
	  running iipsrv on the command line with the argument --bind.
	  For example: ./iipsrv.fcgi --bind localhost:9000
	- Fixed memory problem reported by valgrind with 16bit images.
	  Now simply use memcpy instead of re-assigning memory blocks. Changes to
	  JTL.cc, DeepZoom.cc and Zoomify.cc.
	- Added extra buffer overhead during JPEG compression.
	- Minor fixes to buffer copy code in Writer.h.
	- Fixed memory leak in Memcached code - need to explicitly free returned
	  objects!


01/12/2010:
	- Modified Main.cc to not check in Memcached if there has been a
	  If-Modified-Since parameter sent and to not store 304 or error replies.
	  Otherwise we risk to send 304 replies to requests from uncached browsers.


25/11/2010:
	- Removed final CRLF from JTL, Zoomify and DeepZoom requests, which causes
	  problems with http pipelining in firefox.


24/11/2010:
	- Added extra checks to both TPTImage and KakaduImage for whether the
	  requested resolution exists.
	- Added ability to KakaduImage to downsize resolutions that were not generated
	  during encoding.
	- Added decompressor.finish() to catch block as finish crashes if called after
	  thread environment shut down.


18/11/2010:
	- Fixed problem when clipping when applying watermarks for both 8 and 16 bit images.


15/11/2010:
	- Added memcached support via libmemcached. List of servers passed via
	  MEMCACHED_SERVERS environment variable. Length of time the cache
	  remains valid set by optional MEMCACHED_TIMEOUT environment variable
	  (default is 3600 seconds). Storage is at output level, rather than tile
	  level, so is complementary to internal tile cache.
	  Thanks to Moravian Library in Brno (Moravska zemska knihovna v Brne,
	  http://www.mzk.cz/) R&D grant MK00009494301 & Old Maps Online
	  (http://www.oldmapsonline.org/) from the Ministry of Culture
	  of the Czech Republic.


06/11/2010:
	- Modification to Cache.h to use string::capacity() function instead of length()
	  to determine space used by string.


31/10/2010:
	- Added simple watermarking support via Watermark class. New environment
	  variables added for the watermark image, the opacity and probability.
	  Changes mainly to the TileManager and Session class. Watermarking happens
	  transparently within the TileManager class for all tiles. Thanks to
	  Moravian Library in Brno (Moravska zemska knihovna v Brne, http://www.mzk.cz/)
	  R&D grant MK00009494301 & Old Maps Online (http://www.oldmapsonline.org/)
	  from the Ministry of Culture of the Czech Republic.


15/09/2010:
	- Modified IIPImage.cc to enable handling of images with spectral band
	  indices with mixtures of 3 or 4 digits. For example, H1_pyr_000_090.tif
	  and H1_pyr_2500_090.tif.


05/03/2010:
	- Another fix to JPEGCompressor.cc to fix a crash with very small
	  tiles with libjpeg-8.


23/02/2010:
	- Modified JPEGCompressor.cc to fix compatibility problem with
	  libjpeg version 8. Simply removed jpeg_write_tables from
	  InitCompression function.


09/02/2010:
	- Fixed memory leak in Zoomify.cc and DeepZoom.cc


11/01/2010:
	- JPEG2000 support added via the Kakadu SDK. Added new class
	  KakaduImage derived from the IIPImage class. JPEG2000 support
	  added thanks to Moravian Library in Brno (Moravska zemska knihovna
	  v Brne, http://www.mzk.cz/) R&D grant MK00009494301 & Old Maps Online
	  (http://www.oldmapsonline.org/) from the Ministry of Culture of
	  the Czech Republic.
	- Fix to string literal warnings in Writer.h


08/01/2010:
	- Major changes to the HTTP headers sent by iipsrv. Added
	  HTTP Server id and Last-Modified timestamps to all server output.
	  Checks are now made for a If-Modified-Since response and a
	  304 Not Modified response returned if the timestamps match.
	  This should significantly improve server performance.


04/01/2010:
	- Fixed bug in FIF.cc - the file system prefix was not being
	  initialized for each new image.
	- Layers environment variable changed to MAX_LAYERS to represent
	  the maximum number of layers user is allowed to decode.


03/12/2009: Version 0.9.8 Released


02/12/2009:
	- Adding missing include to IIPImage.cc for compilation with
	  gcc 4.4.1


01/12/2009:
	- Added DeepZoom protocol support. Work carried out thanks to
	  Moravian Library in Brno (Moravska zemska knihovna v Brne,
	  http://www.mzk.cz/) R&D grant MK00009494301 & Old Maps Online
	  (http://www.oldmapsonline.org/) from the Ministry of Culture of
	  the Czech Republic.


29/11/2009:
	- Added SPECTRA.cc class for returning spectral reflectance values
	  from multispectral images.
	- Fix to IIPImage.cc to properly count the number of horizontal and
	  vertical angles (used for multispectral bands).


26/11/2009:
	- Fix to View class to take resampling into account when limiting
	  the CVT output size to the maximum server setting.


17/11/2009:
	- Update to Zoomify to fix way it calculates number of zoom levels.


05/11/2009:
	- Updated the autoconf, aclocal, automake and libtool scripts to the
	  latest versions.


04/11/2009:
	- Added FILESYSTEM_PREFIX environment variable to allow a fixed prefix to
	  be applied to all image paths. Embedded NULL bytes of the form %00 and
	  any "../" are also now stripped out of any path for security reasons.
          (Thanks to Willem Hengeveld for suggesting this)


01/11/2009:
	- Fixes to View.h and View.cc to set the requested size to the maximum
	  allowable if not WID or HEI is set for the CVT command. The correct
	  resolution to use for CVT is now calculated for views smaller than
	  the smallest available.


30/10/2009:
	- Security fixes to Task.cc to make sure while loop is limited to the
	  expected number of arguments. (Thanks to Willem Hengeveld for pointing
	  this out).


19/08/2009:
	- Minor updates to IIPImage.h and IIPImage.cc. FIF.cc also now tests
	  for upper/lowercase .tif and .tiff suffixes.


14/08/2009:
	- Modification to View.cc and CVT.cc to calculate the appropriate
	  resolution as the smallest resolution with a dimension greater size
	  than the requested dimensions. The WID and HEI directives now
	  effectively give bounding dimensions.

11/08/2009:
	- Added simple nearest neighbour resampling to CVT command to allow it to
	  resize to the exact dimensions and not just the nearest available pyramid
	  resolution.
	- CVT Content-disposition tag now gives the image filename allowing the user
	  to save the image directly with this.


01/07/2009:
	- Added quality layer parameter to images for future use with file formats
	  such as JPEG2000 that support this. This allows the decoding of several
	  quality layers via the LYR command. Modifications to the RawTile API
	  as well as IIPImage::getTile resulting in a series of changes to
	  CVT.cc, JTL.CC, TIL.cc, TPTImage.cc, View.h, Main.cc and Environment.h.
	  New startup configuration "LAYERS" to set the default number of layers.
	  Default is 1 otherwise.


22/06/2009:
	- Changes to Zoomify.cc to take into account the fact that Zoomify expects
	  a fixed number of resolution levels.


15/04/2009:
	- Added a flag for padded tiles into RawTile.h. TIFF's are padded out
	  to the tile size, but other formats may not be. Changes to TPTImage,
	  TileManager and CVT to handle this.
	- Also changed the RawTile flag for memory managed tiles.


18/03/2009:
	- Added modification timestamps to the IIPImage and Rawtile classes.
	  The TileManager now checks whether the tile is fresh and reloads it
	  if necessary.


11/03/2009:
	- Several changes to JTL.cc and Cache.h to eliminate a memory leak. Also
	  replaced malloc/free in Rawtile with new/delete.


04/03/2009:
	- Minor changes to IIPResponse.cc to elimate type warnings.


06/06/2008:
	- Modifed the way the image dimensions are stored in the IIPImage class.
	  Rather than simply storing the max size, a vector of available dimensions
	  is saved making it easier to get the size for a given resolution.


05/06/2008:
	- Added Zoomify support via the Zoomify=/path.tif request. Works with both
	  the official flash client and the Zoomify patched OpenLayers javascript
	  client. Work carried out thanks to R&D grant DC08P02OUK006 - Old Maps
	  Online (www.oldmapsonline.org) from Ministry of Culture of the Czech Republic.


09/08/2007:
	- Added a Bits-per-channel OBJ request so that viewers can determine whether
	  to perform contrast adjustment server-side or client-side.


07/08/2007:
	- Added CIELAB conversion and contrast handling to JTL so that it can handle
	  16 bit images.


12/06/2007:
	- Updated URL decoding function in FIF.cc to C++ style and avoid a potential
	  buffer overflow.
	- Changed Task::run arguments to be const std::string& instead of just std::string.


08/06/2007:
	- Changed JTL headers to enable HTTP 1.1 compatible cache control.


13/12/2006: Version 0.9.7 Released


07/11/2006:
	- Fixed the standalone mode, which is now activated by launching with
	  --standalone with an argument giving the socket port or path. For example,
	  localhost:8000 or /tmp/iipsrv.sock.


31/10/2006:
	- Added hillshading Task class and function for simulated raking light
	  visualization using 3D surface normal data. This is used via the SHD
	  command in association with CVT, which takes 2 arguments: the horizontal
	  light source angle in degrees and the vertical angle from the horizontal
	  plane.


26/09/2006:
	- Cleaned up the hash_map and pool_allocator stuff a little to use typedefs
	  instead of #ifdefs.
	- Added the legacy JTLS command class for panoramic views.


22/09/2006:
	- Added an FCGI stand-alone mode usable with lighttpd's spawn-fcgi command.
	- Also changed the IIPImage cache to use a hash_map and pool_alloc memory.


19/09/2006:
	- If we are using appropriate versions of g++, we now use the high
	  performance pool_alloc memory allocators for our cache containers.
	  Also, instead of a std::map, we use the hash_map extension which
	  offers better performance. Otherwise we default to std::map.
	- Fixed problem in TileManager where uncompressed tiles in the cache
	  were not being cropped when converted to JPEG. The IIPImage tile_width
	  and tile_height fields now hold the base tile size and not the current
	  tile size.


18/092006:
	- Added a "Last-Modified" and "ETag" header to the CVT HTTP response
	  to prevent double requests from being made by web browsers.
	- Fixed bug in CVT where the tile size was being incorrectly set from
	  the IIPImage object and not the tile itself, which was a problem
	  when getting tiles from the cache.


15/09/2006:
	- Changed the Cache keys to be simple strings rather than custom
	  objects. This has solved one of the crashing problems when tiles
	  are deleted from the cache.


29/08/2006:
	- Added Writer class to shield the command implentations from any
	  FCGI specific functions.


28/08/2006:
	- *Major* refactoring of the code. Each command is now called via its own
	  Task class (command pattern), with no processing done in Main.cc.
	  OBJ commands are in OBJ.cc and each output command (eg TIL,CVT etc)
	  now have their own classes.
	- The xangle and yangle variables are now in the View class, which
	  was previously named the ImageTransform class.


25/08/2006:
	- Cleaned up the option variable parsing in Main.cc. It is now mostly
	  done via an Environment class, which checks for defaults etc.


16/08/2006:
	- Moved QLT limit checking from Main into JPEG class. Also now check
	  for empty strings.


08/08/2006:
	- Changed the contrast adjustment code to limit the result to a max of
	  255.0 as this was creating problems with the windows build.


07/03/2006: Version 0.9.6 release.


13/02/2006:
	- Fixed another problem on Mac OS X in TPTImage.cc. The number of
	  channels and bits per sample were giving strange values, so a
	  temporary uint16 variable is now used and cast from. It now works
	  perfectly on Mac :-)


09/02/2006:
	- Changed the start_t and start_u types in Timer.h to long for
	  compatibility with Solaris and Mac OS X.
	- Some code cleanups in the IIPResponse class.


23/01/2006:
	- Added an extra timer for tile insertion - this is the slowest
	  cache operation. We should look to put this in a separate
	  thread at some point!


18/01/2006:
	- Added support for ptif suffix images. These are in fact just
	  pyramidal TIFF images.


11/01/2006:
	- More fixes to the TileManager class. Cache can now handle
	  multiple compression types for the same tile simultaneously.


24/12/2005:
	- Major rewrite of the TileManager class. Now much more concise.


21/10/2005:
	- Added a check in JPEGCompressor for the number of channels.
	  JPEG can handle only image with either 1 or 3 channels.


13/10/2005:
	- Added a TileManager class to act as a higher level access to
	  the tile cache. It checks whether a JPEG compressed tile
	  already exists and if not decodes one from the source image.
	  It also crops any edge tiles to the correct size (required
	  for the new Vips TIFF format).


12/10/2005:
	- Fixed a JTL problem with the new tiled TIFF format. The edge
	  tiles are now cropped before being sent out.
	- Reworked JTL to just forward the request to JTLS rather than
	  duplicating the code there.


09/06/2005:
	- Changed IIPImage.cc to use glob conditionally if glob has been
	  detected. This is needed for mingw compilation.


01/04/2005:
	- Completed an LRU tile cache with the ability to set the max
	  cache size via the configuration variable MAX_IMAGE_CACHE_SIZE,
	  specified in MB.


22/03/2005:
	- Added new Timer class to handle timing data to debug tile
	  access, command and total request times.


06/01/2005:
	- Found problem in the CVT code when dealing with image sequences
	  of different numbers of channels. We have to reload the channel
	  information.


15/12/2004:
	- CVT now works with the new standard compliant TIFF tile format
	  as used by vips-7.10 and later.


10/12/2004:
	- CVT now works with 16 bit TIFF. The compression type reported
	  by TIL also switches from JPEG with 8 bit images to none with
	  16 bit.


08/12/2004:
	- Added CNT contrast command support. Also added check to
	  TPTImage openImage() for whether our image is in fact
	  tiled or not, which can cause the server to crash.


07/12/2004:
	- Added 16 bit support. Changes to RawTile - the data is now
	  a generic (void*) and there are now fields for channels per
	  sample and bits per channel. Changes also to TPTImage.cc,
	  Main.cc and JPEGCompressor.cc.


01/09/2004:
	- Changed the LAB2sRGB code to allow a/b values from
	  +-127 as per the TIFF spec instead +-100.
	- Also fixed a problem caused by signed/unsigned comparisons
	  in ImageTransform with requests for CVT sizes smaller than
	  the tile size.


26/08/2004:
	- Added largefile support by simply adding a configure
	  directive that will add the appropriate defines.


05/07/2004:
	- Fixed problem in JPEGCompressor.cc concerning the value of
	  a structure that we try to read after de-allocating memory.
	  Only seems to be a problem with MSVC++ compiler. (Thanks to
	  Chris Tuijn for spotting this).


11/05/2004: Version 0.9.5 release.


04/05/2004:
	- Moved the colorspace check from TPTImage::getTile to
	  TPTImage::openImage so that a Colorspace request will always
	  have an associated colour space and not just after getTile
	  has been called. We assume for now that all the tiles of an
	  image are all of the same colour space.


21/05/2004:
	- Removed no-cache pragma from CVT header. Also modified
	  max_CVT variable to limit the effective size and not the
	  total image size. ie a small RGN of a massive image can
	  still be sent OK. The resolution calculations have been
	  moved into ImageTransform and is now performed at the last
	  moment in the CVT section.


16/05/2004:
	- Added MAX_CVT environment variable to limit width and height
	  requests of CVT commands. The default is set to 5000 pixels.


02/04/2004:
	- Added SDS command support. This can be used for specifying
	  subimages or the horizontal/vertical angle in 3D sequence
	  images and will eventually replace the use of JTLS by the
	  client. Current usage is SDS=h,v where h and v are the
	  horizontal and vertical sequence angles.


01/04/2004:
        - Fixed length given by the error response. We now count both
          the code and the argument.


30/03/2004:
        - Fixed TIL to only send the MIME type once before the tile
          sequence.
        - Added better error handling. The IIPResponse is now set
          whenever we have a problem in Main.cc. Plus the catch
          clause now checks for an error in IIPResponse and sends
          this if available rather than the advertising banner.


29/03/2004:
        - Changed the vertical and horizontal views syntax back to
          old style.
        - Fixed problem with the number of CRLF's after the MIME type:
          Apache complains if there are not 2 sets of CRLF.
        - Changed the IIPImage metadata map to use the string class
          rather than char* - seems to fix a freeze problem.


06/03/2004:
	- More fixes to RGN code. Moved the verification logic into
	  the ImageTransform class itself rather than having it in
	  Main.cc. Also fixed a crash resulting from the use of
	  inlining - a gcc bug perhaps? Anyway, now perfectly stable.


05/03/2004:
	- Some minor fixes to the RGN code to prevent crashes from
	  images of less than 8 pixels in size.


04/03/2004:
	- Finished implementation of RGN CVT modifier. Can now specify
	  a region to CVT rather than always having the whole image.
	- Updated embedded XHTML advertising page.
	- Some doxygen-related cleanups and documenting.


03/03/2004:
	- Changed Horizontal-views and Vertical-views return syntax to
	  return the number of views also (request by Denis):
	  Vertical-views/<number views>:view1 view2 ...
	  eg. Vertical-views/3:0 90 180.


02/03/2004:
	- Added automatic colour spaces conversion for CIELAB images
	  to sRGB in CVT mode.


14/12/2003:
	- Added Content-disposition headers to the JTL,JTLS and CVT output.


10/11/2003:
	- Added missing std:: prefixes to a few STL variables in IIPImage.h
	  and IIPResponse.h.
	- Fixed the TIL command to return only the tiles within the
	  rectangle defined by the specified range rather than all of them.


25/10/2003:
	- Fixed missing value in error message for non decodable tiles
	  in TPTImage.cc and erroneous extra CRLF in the Colorspace
	  reply.


22/10/2003:
	- Changed the IIPImage class to give the horizontal and
	  vertical angles a default value of 0,90 for non-sequence
	  images.


11/10/2003:
	- Removed the new allocator in getFileName() in IIPImage.cc to
	  a statically allocated buffer of size 1024.


04/10/2003:
	- Generalised the metadata handling in Main to cope with any
	  available metadata.
	- Changed the way Basic-info and Summary-info work to simply
	  add more objects to the request string rather than try to
	  handle it themselves. Nicely eliminates duplicate handler code
	  without introducing classes or external functions for each obj.
	- Also fixed the server capability return code to follow the IIP
	  spec properly.


03/10/2003:
	- Added tracking of image data to the IIPResponse class. In this
	  way, we can print an error if we have an uncomplete command
	  syntax. eg. a WID without a CVT. We should now never not have
	  some sort of response from the server.
	- Also added Author, Subject etc metadata handling to IIPImage
	  and the necessary handlers to IIPResponse.


15/09/2003:
	- Added doxygen compatible comments to the header files. The
	  generated documentation is in the doc subdirectory.
	- Changed sprintf to snprintf in Main.cc for the vertical-views
	  handler; snprintf is already used everywhere else.
	- Added IIPResponse class to handle message passing back to the
	  client from OBJ requests. This allows for better error and
	  mime header handling and eliminates having to use FCGX_Fprintf.
	- Added SIGHUP handling to the other signals handled - we simply
	  exit and allow mod_fastcgi to restart us.
	- Added support for IIP-opt-comm and IIP-opt-obj requests.
	- Removed the deprecated Max-sequence and Vertical-views object
	  handlers.


12/09/2003: Version 0.9.4 release.
	- Added content-type heading to error returns.
	- Added default catch() clause to the end of the main try block.


11/09/2003:
	- Added Base64 URL decoding for the image path argument supplied
	  to the FIF command.
	- Cleanups to eliminate most GCC -Wall warnings.


10/09/2003:
	- Changed tolower to ::tolower to fix compilation problem using
	  GCC 3x.
	- Logging cleanup.


08/09/2003:
	- Major cleanup up the JPEGCompressor class.
	- Added bits per pixel to the IIPImage copy constructors.
	- Used the new JPEG buffer-buffer functions to add support for the
	  CVT command (limited to JPEG output only).


07/09/2003:
	- Modified the JPEGCompressor class to allow stream-based buffer
	  to buffer encoding via 3 new functions (init, compressstrip and
	  finish).


03/09/2003:
	- Fixed bug in TPTImage.cc. Added TIFFGetField commands for tile_width
	  and tile_height so that they get reset to the correct value even if
	  we loop through the end of a row.
	- Added a bits per pixel field to the IIPImage class.


02/09/2003:
	- Fixed mis-placed jpeg_set_defaults in JPEGCompressor.cc.
	  Was being called after some individual values were set. This only
	  seemed affected the dct_method. Should compress faster now.


28/08/2003:
	- Added WID and HEI command support.


25/08/2003:
	- Autoconf cleanups. Now properly detect for JPEG and TIFF.


24/08/2003:
	- Improvements to the configure script. Can now completely disable
	  the dynamic module loading code from even compiling.
	- The FCGI development library is now included in the distribution
	  for convenience and is integrated into the top-level configure
	  system. It is only used if it is not found on the computer.


22/08/2003:
	- Added extra variable to track the current vertical position as
	  well as the horizontal. Fixes bug when switching between vertical
	  angles on sequence zero.
	- XHTMLified the advertising banner :-)


22/03/2003: Version 0.9.3 release.
	- Reworked and cleaned up the TIL compression type and subtype data
	  stream prefix with reference to the FlashPix specification.


21/03/2003:
	- All commands are converted to lower case to handle the java JAI
	  IIP implementation which does not properly follow the spec.
	- Also fixed typo in the Colorspace OBJ reply.


15/03/2003:
	- Modifications to the JPEGCompressor constructor to take only the
	  Q factor. Plus the environment variable JPEG_QUALITY can
	  set the default Q factor.
	- Plus added an #undef HAVE_STDLIB_H to JPEGCompressor.h which was
	  interfering with libjpeg. No compiler warnings now even
	  with -pendantic set :-)


13/03/2003:
	- Added extended colour space handling. The TIFF image now has its
	  colourspace extracted and a ColourSpace enum type now exists.
	  Greyscale, RGB and CIELAB are now handled, though the latter is not
	  in the official IIP spec.


10/03/2003:
	- Changed RawTile copy constructor to use memcpy instead of looping
	  through an array: Big speed improvement :-)


08/03/2003:
	- Added USR1 and TERM signal handling to main loop: We now have some
	  stats printed in the logfile on shutdown.
	- Modified IIPImage to accept a filename pattern variable, so that
	  the "_pyr_" image sequence pattern can be user modified.
	- Plus started work on a new tile cache system, but seems very slow,
	  so will mothball it till after the forthcoming release.


10/11/2002:
	- Changes to some header files etc to make it compatible with gcc 3.2:
	  Mainly STL string specifiers, plus replacement of slist type
	  with std::list.


24/03/2002
        - Changed error handling to follow IIP return code specification
          for unsupported objects and commands. Should do this for
	  each individual exception also.
        - Added runtime configuration variable for max image cache size.


18/03/2002: Version 0.9.2 release.
	- Changes to JPEGCompressor.cc: Fixed bug when encoding very small
	  tiles. Sometimes the JPEG data is larger than the original
	  so we need to allocate some extra memory just in case.
	- Also fixed the iip_empty_output_buffer( j_compress_ptr cinfo )
	  function. Now properly empties the buffer and returns TRUE.
	- The Compress() routine now passes the entire image buffer array
	  into jpeg_write_scanlines rather than doing it row by
	  row. The row array is dynamically allocated and deleted
	  at the end.
	- Added proper copy constructor to RawTile class to properly copy
	  data without leaving dangling pointers.


09/08/2001:
	- Added time stamp.
	- Some minor changes to the JPEG wrapper - a couple of ints
	  changed to size_t's and a conditional added just before
	  the memcopy code.


07/07/2001: Version 0.9.1 release.
	- Added field for number of bands in Rawtile.h, so that we can now
	  view 1-band black and white as well as 3-band colour images
	- Added missing JTL command handler for single non-sequential images
	  This does the same as JTLS command, but supplies 0 for sequence
	  and angle.


05/03/2001: Version 0.9 release.
	- Bug fixes: moving IIPImage objects in the cache was resulting
	  in lost information.
	- DSOImage memory bug. Modules should handle their own cleanup
	  in close_image, which is now called by the ~DSOImage


04/03/2001:
	- Changed ModuleLoader to a DSOImage derived class of IIPImage.
	- Use a STL map of image type to module path keywords instead
	  of trying to store caches of DSOImages.
	- Clean up and rationalisation of IIPImage class and derived
	  classes.


01/03/2001:
	- Added tokenizer class.
	- Now checks for variables passed to fcgi at start up time
	  via --initial-env directive within Apache.
	- Added basic ModuleLoader class for loading external image decoders.
	- Fixes so that it no longer crashes even with null input query etc.
	- Removed ifdef DEBUG stuff.


27/02/2001:
	- Added Tile-size directive and related IIPImage::getTileWidth() etc.
	- Allowing for various tile sizes to be used :)
	- Improved logfile reporting.
