Mercurial > hg > orthanc-book
annotate Sphinx/source/faq/transcoding.rst @ 449:2922fb1bd65e
fix links
author | Sebastien Jodogne <s.jodogne@gmail.com> |
---|---|
date | Fri, 03 Jul 2020 09:33:10 +0200 |
parents | 943515b68158 |
children | 7d8b95b1b22c |
rev | line source |
---|---|
275 | 1 .. _transcoding: |
2 | |
3 Transcoding of DICOM files | |
4 ========================== | |
5 | |
411 | 6 .. contents:: |
7 | |
8 | |
275 | 9 General information |
10 ------------------- | |
11 | |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
12 **DICOM transcoding** refers to the process of changing the |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
13 :ref:`transfer syntax <dicom-pixel-data>` of some DICOM instance. |
275 | 14 |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
15 Transcoding can be used to **compress** DICOM images, which is useful |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
16 to reduce the required storage area or to optimize the network |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
17 bandwidth for exchanges between sites. Conversely, transcoding can be |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
18 used to **decompress** DICOM images, which is needed as many DICOM |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
19 viewers or specialized analysis software do not provide support for |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
20 compressed transfer syntaxes. |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
21 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
22 Support for transcoding was introduced in Orthanc 1.7.0. |
275 | 23 |
24 | |
25 Motivation for transcoding | |
26 -------------------------- | |
27 | |
28 Let's consider the following basic workflow, in which some imaging | |
29 workstation must access a medical image that originates from a PACS | |
30 and that is served through an Orthanc proxy: | |
31 | |
32 .. image:: ../images/Transcoding1.svg | |
33 :align: center | |
34 :width: 700px | |
35 | |
36 This is quite a common situation, e.g. in university hospitals where | |
37 researchers must access medical images without having authorization to | |
38 log in the clinical PACS. It is also common if the main PACS restricts | |
39 the number of workstations that can directly be connected to it, or if | |
40 Orthanc acts as gateway through Internet. | |
41 | |
42 The problem is that the software running on workstations might not be | |
43 able to display some DICOM transfer syntaxes. This is especially true | |
44 in research software, that is often limited to uncompressed transfer | |
45 syntaxes. For instance, let's consider the following scenario where a | |
46 workstation wants to access an image from the PACS: | |
47 | |
48 .. image:: ../images/Transcoding2.svg | |
49 :align: center | |
50 :width: 700px | |
51 | |
52 A typical PACS system will decide, when requested to export an image | |
53 using DICOM C-Store, to compress the image in order to reduce the | |
54 network bandwidth and the storage requirements. Orthanc is fine with | |
55 it: As a vendor neutral archive, Orthanc can basically | |
56 receive/store/transmit any DICOM transfer syntax. Unfortunately, this | |
57 might not be the case of the target workstation, that is often limited | |
58 to some selected transfer syntaxes. As a consequence, the workstation | |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
59 will complain about not being to use the DICOM file (in the situation |
275 | 60 depicted above, because the PACS has decided to send the DICOM image |
61 using the JPEG2k transfer syntax). | |
62 | |
63 | |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
64 Transcoding in Orthanc |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
65 ---------------------- |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
66 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
67 Orthanc 1.7.0 was the first release of Orthanc to feature built-in |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
68 support for DICOM transcoding. Transcoding is available at multiple |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
69 levels, as depicted by the green arrows on the following drawing: |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
70 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
71 .. image:: ../images/Transcoding-1.7.0.svg |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
72 :align: center |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
73 :width: 500px |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
74 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
75 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
76 * **Automated transcoding while ingesting**. Orthanc can be configured |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
77 to automatically transcode each DICOM instance it receives (either |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
78 by DICOM protocol or by REST API) to a fixed transfer syntax. This |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
79 is especially useful to either create an archive of compressed files |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
80 (for long-term archiving), or to create a DICOM buffer with |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
81 uncompressed files (for interfacing with DICOM modalities that do |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
82 not support compressed transfer syntaxes). If the transcoding fails, |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
83 the DICOM instance is still stored using its original transfer |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
84 syntax. |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
85 |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
86 Automated transcoding is enabled by setting the :ref:`configuration |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
87 option <configuration>` ``IngestTranscoding`` to the transfer syntax |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
88 UID of interest. For instance, setting ``IngestTranscoding`` to |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
89 ``1.2.840.10008.1.2.1`` will decompress all the received DICOM |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
90 instances. Conversely, setting it to ``1.2.840.10008.1.2.4.70`` will |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
91 compress and store images using JPEG-LS (lossless). |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
92 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
93 * **Decompression while sending instances using the DICOM protocol**. |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
94 Orthanc can be configured to automatically decompress DICOM images |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
95 on its outgoing connections, if the remote modality does not support |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
96 the compressed transfer syntax of the source DICOM instances. This |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
97 feature is available for both :ref:`DICOM C-Move and C-Get commands |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
98 <dicom-move>`. Note that Orthanc won't transcode DICOM instances to |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
99 a compressed transfer syntax over the DICOM protocol. |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
100 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
101 By default, this automated decompression is enabled. This might be |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
102 undesirable if you want to limit the resources that are used by |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
103 Orthanc. As a consequence, you can disable this feature either |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
104 globally (by setting configuration option ``TranscodeDicomProtocol`` |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
105 to ``false``), or on a per-modality basis (by setting the option |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
106 ``AllowTranscoding`` to ``false`` in the ``DicomModalities`` |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
107 section). |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
108 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
109 .. highlight:: bash |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
110 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
111 * **Transcoding while sending instances to an Orthanc peer**. The |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
112 ``/peers/{id}/store`` route in the Orthanc REST API allows to send |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
113 DICOM resources (patients, studies, series or instances) to |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
114 :ref:`another Orthanc server over HTTP/HTTPS <peering>`. Starting |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
115 with Orthanc 1.7.0, the ``Transcode`` option can be used in the JSON |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
116 POST body to instruct to transcode the DICOM files before they are |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
117 sent. For instance:: |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
118 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
119 $ curl -X POST http://localhost:8042/peers/sample/store -d '{"Transcode":"1.2.840.10008.1.2.4.70","Resources":["66c8e41e-ac3a9029-0b85e42a-8195ee0a-92c2e62e"]}' |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
120 |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
121 * **Transcoding using the REST API**. Starting with Orthanc 1.7.0, |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
122 some routes in the REST API also accept the ``Transcode`` option |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
123 in their JSON POST body. Those routes notably include: |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
124 |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
125 * The routes to create ZIP files or DICOMDIR archives (``.../media`` |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
126 and ``.../archive``). |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
127 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
128 * The routes to modify DICOM resources |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
129 (``/{patients|studies|series|instances}/{id}/modify``). |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
130 |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
131 Importantly, if you need to transcode JPEG2k DICOM instances, you'll |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
132 have to install the :ref:`GDCM plugin <gdcm>` that replaces the |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
133 built-in transcoder of Orthanc based on DCMTK, by the GDCM transcoder. |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
134 |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
135 The following :ref:`advanced configuration options <configuration>` |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
136 are also available to control transcoding: |
275 | 137 |
428
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
138 * ``BuiltinDecoderTranscoderOrder`` controls the transcoder that is |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
139 used by Orthanc. It specifies whether the built-in transcoder of |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
140 Orthanc (that uses DCMTK) is applied before or after the transcoding |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
141 plugins, or not applied at all. "After" means that the built-in |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
142 transcoder is applied if all the transcoding plugins have failed to |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
143 transcode the image. |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
144 |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
145 * ``DicomLossyTranscodingQuality`` controls the quality level of lossy |
943515b68158
documented transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
427
diff
changeset
|
146 compression (notably for JPEG transcoding). |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
147 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
148 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
149 Solutions to avoid transcoding |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
150 ------------------------------ |
275 | 151 |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
152 Up to release 1.6.1, Orthanc didn't feature support for transcoding |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
153 DICOM instances. In other words, the Orthanc core never changed the |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
154 :ref:`transfer syntax <dicom-pixel-data>` of some DICOM instance when |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
155 it had to send it to another modality using the DICOM protocol. |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
156 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
157 Three workarounds were available to bypass the need for DICOM |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
158 transcoding in Orthanc <= 1.6.1. These workarounds are still valid in |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
159 Orthanc >= 1.7.0, if transcoding is undesirable (e.g. if Orthanc is |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
160 being run on a computer with sparse CPU/RAM resources). |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
161 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
162 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
163 Refusing transfer syntaxes |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
164 ^^^^^^^^^^^^^^^^^^^^^^^^^^ |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
165 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
166 The first solution consists in making Orthanc **refuse to accept the |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
167 transfer syntaxes** that are not supported by the workstation. This is |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
168 depicted in the following diagram: |
275 | 169 |
170 .. image:: ../images/Transcoding3.svg | |
171 :align: center | |
172 :width: 700px | |
173 | |
174 .. highlight:: json | |
175 | |
176 If Orthanc tells the PACS that is doesn't accept, say, DICOM JPEG2k, | |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
177 the source PACS will be aware of this, and will take care of |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
178 transcoding the DICOM files before they are sent to Orthanc. This is |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
179 the role of the following :ref:`configuration options <configuration>` |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
180 that specifies which transfer syntaxes are accepted by Orthanc:: |
275 | 181 |
182 { | |
183 "DeflatedTransferSyntaxAccepted" : true, | |
184 "JpegTransferSyntaxAccepted" : true, | |
185 "Jpeg2000TransferSyntaxAccepted" : true, | |
186 "JpegLosslessTransferSyntaxAccepted" : true, | |
187 "JpipTransferSyntaxAccepted" : true, | |
188 "Mpeg2TransferSyntaxAccepted" : true, | |
189 "RleTransferSyntaxAccepted" : true, | |
190 "UnknownSopClassAccepted" : false | |
191 } | |
192 | |
193 If all of those options are set to ``false``, Orthanc will only | |
194 receive uncompressed transfer syntaxes (obviously provided that the | |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
195 source PACS itself supports DICOM transcoding). |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
196 |
275 | 197 |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
198 Using external conversion tools |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
199 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
200 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
201 The second solution consists in **applying an external conversion |
275 | 202 tool** to every DICOM image that is received by Orthanc. The standard |
203 command-line tools ``gdcmconv`` from `GDCM | |
204 <http://gdcm.sourceforge.net/html/gdcmconv.html>`__ or ``dcmconv`` | |
205 from `DCMTK <https://support.dcmtk.org/docs/dcmconv.html>`__ can be | |
206 used to change the transfer syntax of a given DICOM file. These tools | |
207 can be invoked from a :ref:`Lua script <lua>` (check out | |
208 ``OnStoredInstance()`` callback) or from an :ref:`Orthanc plugin | |
209 <creating-plugins>` (check out | |
210 ``OrthancPluginRegisterOnStoredInstanceCallback()`` function). A | |
211 sample Lua script that converts every incoming DICOM file to the | |
212 JPEG2k transfer syntax is `part of the Orthanc sources | |
449 | 213 <https://hg.orthanc-server.com/orthanc/file/default/OrthancServer/Resources/Samples/Lua/AutomatedJpeg2kCompression.lua>`__. Note |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
214 that this solution makes no sense anymore in Orthanc 1.7.0, as it |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
215 provides built-in support for transcoding. |
275 | 216 |
217 | |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
218 Transcoding buffer |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
219 ^^^^^^^^^^^^^^^^^^ |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
220 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
221 Finally, as a third solution, it is possible to **combine two Orthanc |
275 | 222 servers**, the first one being configured to accept any transfer |
223 syntax, and the second one being responsible to serve the DICOM files | |
224 after conversion to uncompressed transfer syntax (which should be | |
225 compatible with any workstation): | |
226 | |
227 .. image:: ../images/Transcoding4.svg | |
228 :align: center | |
229 :width: 700px | |
230 | |
427
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
231 In this solution, the first Orthanc server acts as a transient server |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
232 that implements the decompression (i.e. it transcodes all the DICOM |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
233 instances it receives to an uncompressed transfer syntax). To carry on |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
234 the transcoding, this first Orthanc server can be: |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
235 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
236 * either an instance Orthanc >= 1.7.0, with transcoding enabled, or |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
237 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
238 * an instance of Orthanc (any version) equipped with a plugin or an |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
239 external script to do the necessary conversions to an uncompressed |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
240 transfer syntax, as explained in the second solution above. |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
241 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
242 Whenever a DICOM instance is received by the first Orthanc, the DICOM |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
243 instance is thus transcoded. The first Orthanc server automatically |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
244 forwards all the transcoded instances to the second instance of |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
245 Orthanc, thanks to a :ref:`Lua script <lua>` or an :ref:`external |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
246 script <rest>`, taking advantage of :ref:`Orthanc peering <peering>`. |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
247 |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
248 Contrarily to the second solution, this solution has the advantage of |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
249 better scalability (as decompression can be a time-consuming |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
250 operation). The second instance of Orthanc can run even on a low-end |
71281b540ca1
updating old documentation about transcoding
Sebastien Jodogne <s.jodogne@gmail.com>
parents:
419
diff
changeset
|
251 computer, with any version of Orthanc. |