.. _webviewer:


Web Viewer plugin
=================

.. contents::

This **official** plugin extends Orthanc with a Web viewer of medical images.

For general information, check out the `official homepage of the
plugin <http://www.orthanc-server.com/static.php?page=web-viewer>`__.


Compilation
-----------

.. highlight:: text

The procedure to compile these plugins is similar of that for the
:ref:`core of Orthanc <compiling>`. The following commands should work
for every UNIX-like distribution (including GNU/Linux)::

  $ mkdir Build
  $ cd Build
  $ cmake .. -DSTATIC_BUILD=ON
  $ make

The compilation will produce a shared library ``OrthancWebViewer``
that contains the Web viewer plugin.  Pre-compiled binaries for
Microsoft Windows `are also available
<http://www.orthanc-server.com/browse.php?path=/plugin-webviewer>`__.


Usage
-----

.. highlight:: json

You of course first have to :ref:`install Orthanc <compiling>`. Once
Orthanc is installed, you must change the :ref:`configuration file
<configuration>` to tell Orthanc where it can find the plugin: This is
done by properly modifying the ``Plugins`` option. You could for
instance use the following configuration file::

  {
    "Name" : "MyOrthanc",
    [...]
    "Plugins" : [
      "/home/user/OrthancWebViewer/Build/libOrthancWebViewer.so"
    ]
  }

.. highlight:: text

Orthanc must of course be restarted after the modification of its
configuration file. The log will contain an output similar to::

  # Orthanc ./Configuration.json 
  W0226 16:59:10.480226  7906 main.cpp:636] Orthanc version: mainline
  [...]
  W0226 16:59:10.519664  7906 PluginsManager.cpp:258] Registering plugin 'web-viewer' (version 1.0)
  W0226 16:59:10.519696  7906 PluginsManager.cpp:148] Initializing the Web viewer
  W0226 16:59:10.520004  7906 PluginsManager.cpp:148] Web viewer using 6 threads for the decoding of the DICOM images
  W0226 16:59:10.520021  7906 PluginsManager.cpp:148] Storing the cache of the Web viewer in folder: OrthancStorage/WebViewerCache
  W0226 16:59:10.522011  7906 PluginsManager.cpp:148] Web viewer using a cache of 100 MB
  [...]
  W0226 16:59:10.530807  7906 main.cpp:516] HTTP server listening on port: 8042
  W0226 16:59:10.581029  7906 main.cpp:526] DICOM server listening on port: 4242
  W0226 16:59:10.581066  7906 main.cpp:533] Orthanc has started

Once a :ref:`DICOM series <model-world>` is opened using Orthanc
Explorer, a yellow button entitled ``Orthanc Web Viewer`` will show
up. It will open the Web viewer for that particular series.  See also
the demonstration video on `official homepage of the plugin
<http://www.orthanc-server.com/static.php?page=web-viewer>`__.


Advanced options
----------------

.. highlight:: json

The configuration of the Web viewer can be fine-tuned by adding some options::

  {
    "Name" : "MyOrthanc",
    [...]
    "Plugins" : [
      "/home/user/OrthancWebViewer/Build/libOrthancWebViewer.so"
    ],
    "WebViewer" : {
      "CachePath" : "WebViewerCache",
      "CacheSize" : 10,
      "Threads" : 4
    }
  }

* ``CachePath`` specifies the location of the cache of the Web
  viewer. By default, the cache is located inside the storage
  directory of Orthanc.
* ``CacheSize`` specifies the maximum size for the cached images, in
  megabytes. By default, a cache of 100 MB is used.
* ``Threads`` specifies the number of threads that are used by the
  plugin to decode the DICOM images.