ANNOUNCE

ANNOUNCEMENT

Version 3.7.1 of the OFFIS DCMTK (DICOM ToolKit) software is now
available for public release.  This release includes the following main
changes over the previous version 3.7.0:

- DCMTK 3.7.1 builds correctly on older and up-to-date versions of GNU
  gcc (10.5.0 to 15.2.0), Clang (14.0.6 to 21.1.8), Apple Clang
  (17.0.0), and Microsoft Visual Studio (2017 to 2026).

- Tested with the following operating systems/environments:
  - Android on arm64
  - FreeBSD on x86_64
  - Linux on x86_64, x86 and s390x
  - MacOS X on x86_64 and arm64
  - NetBSD on x86_64
  - OpenBSD on x86_64
  - OpenIndiana on x86_64
  - Windows (including MinGW) on x86_64 and x86

  For a complete list of tested systems and compilers, see INSTALL file.

- Updated DICOM data dictionary, list of SOP classes, well-known frame
  of references, transfer syntaxes, code definitions, supported context
  group classes, and directory record types for DICOM standard release
  2026d.

- A large number of bugs and vulnerabilities have been fixed in this
  release.  In particular, the following issues from DCMTK's issue
  tracker have been addressed (see
  https://support.dcmtk.org/redmine/issues/<number> for details):

  #126,  #145,  #246,  #684,  #1127, #1128, #1146, #1163, #1181, #1187,
  #1188, #1190, #1191, #1193, #1194, #1197, #1198, #1201, #1202, #1206,
  #1207, #1208, #1211, #1212, #1213, #1214, #1215, #1217, #1218, #1219,
  #1221, #1222, #1223, #1224, #1225, #1226, #1227, #1228, #1229, #1230,
  #1231, #1232, #1233, #1234, #1235, #1236, #1237, #1238, #1239, #1240,
  #1241, #1242, #1243, #1244, #1245, #1246, #1247, #1248, #1249, #1250,
  #1252, #1253, #1254, #1255, #1256, #1257, #1259, #1260, #1261, #1262,
  #1263, #1264, #1265, #1266, #1267, #1268, #1269, #1270, #1271, #1272,
  #1276, #1277, #1278, #1280, #1281, #1282, #1283, #1284, #1285.

- Added a limit for the nesting depth of sequences when parsing DICOM
  data (default: 64 levels) in order to prevent stack overflows.  The
  limit can be changed at compile time (DCMTK_MAX_SEQUENCE_NESTING) and
  at runtime, e.g. for DcmFileFormat, DcmSCU and DcmSCP.

- Added a new command line tool 'dcmtk' that maintains a list of all
  command line tools available in DCMTK and acts as a proxy, allowing
  the user to call a tool through 'dcmtk', e.g.
  'dcmtk dcmdump file.dcm'.  Alternatively, 'dcmtk dump file.dcm' could
  be used, so there's no need to remember the name of the dump tool.

- Added command line options to the compression tools that enable the
  caller to select how icon images should be handled: compress or leave
  uncompressed.  By default, icon images are compressed.

- Added wlmscpfs command line option that allows for accepting arbitrary
  non-sequence attributes on the main level of the C-FIND request as
  return key attributes and filled with the values found in the matching
  worklist files.  In addition, explicit support for various optional
  attributes has been added, e.g. for veterinary medicine.

- dcmqrscp now consistently enforces the access mode of a storage area:
  write-only areas ("W") refuse query/retrieve, and DIMSE commands that
  do not match the abstract syntax of their presentation context are
  rejected, so read-only areas ("R") can no longer be written to.

- Added dcmodify command line option for the conditional execution of
  modifications (--process-if).  Conditions support existence checks,
  equality and ordering operators.  Multiple conditions are combined
  with logical AND.

- Added dcm2json command line options for handling missing Specific
  Character Set, equivalent to the options available in dcm2xml.

- The dcm2json and json2dcm tools now correctly handle Specific
  Character Set when converting between DICOM and JSON.  When converting
  to JSON, by default the value of Specific Character Set will be
  retained even though the JSON dataset itself is expressed in UTF-8.
  When converting from JSON to DICOM and encountering a Specific
  Character Set other than ISO_IR 192, json2dcm will attempt to convert
  the character set back to its original form.

- Added support for N-GET to the networking classes DcmSCU and DcmSCP.
  Furthermore, DcmSCU allows for overriding the Requested SOP Class UID
  of N-ACTION, N-GET and N-SET requests, and N-ACTION requests without a
  dataset are now handled correctly by DcmSCU and DcmSCP.

- In the DcmSCU class, C-FIND-RQ, C-FIND-RSP, C-STORE-RQ, N-GET and
  N-ACTION datasets are now logged to separate loggers, which can be
  enabled or disabled individually for each DcmSCU instance.

- Fixed several issues in the multi-threaded SCP pool (DcmSCPPool): once
  a worker had been re-used, a single slow client blocked the whole
  server; transient errors stopped the server; failed workers leaked
  pool slots.  Also fixed a data race in the initialization of the
  network state machine, which could cause sporadic association failures
  (e.g. TLS handshake errors) with concurrent associations.

- Added minimal support for DICOM CP-2595 "Extend KOS to support more
  metadata for manifest use case" to DCMTK's SR implementation.  This
  extension is needed for the new IHE-RAD Integration Profile MADO
  (Manifest-Based Access to DICOM Objects), which is, e.g. used for the
  European Health Data Space (EHDS).

- The JPEG input plugin of img2dcm by default removes all APPn markers
  from the encapsulated stream.  This also drops the Adobe APP14 marker
  (0xFFEE), whose color transform flag some JPEG decoders and viewers
  rely on to decide whether a YCbCr to RGB conversion has to be applied
  during decoding.  The new --keep-app option keeps a single APPn marker
  and may be given multiple times, e.g. use "--keep-app 14" to retain
  the Adobe marker.

- The CIELab color conversion in class IODCIELabUtil now computes CIELab
  values relative to the D50 illuminant, as required for the ICC Profile
  Connection Space encoding used by DICOM, instead of D65.  This affects
  all attributes that are converted from or to RGB by DCMTK, in
  particular Recommended Display CIELab Value in segmentation objects
  (module "dcmseg") and Graphic Layer Recommended Display CIELab Value in
  presentation states (module "dcmpstat").

- Improved support for Label Map Segmentations: the background is now
  handled via Pixel Padding Value as defined by the standard, and
  check() verifies that every pixel value is described by a segment.
  Furthermore, reading and writing large segmentations and other
  enhanced multi-frame objects is now considerably faster.

- Replaced the OFUUID implementation with a completely new one.  The old
  implementation represented a UUID version 1, while the new one is a
  UUID version 7.  It offers monotonicity, and improved unguessability.
  In addition, it mitigates security issues because it does not use a
  MAC address as is the case with version 1.

- Improved handling of DICOM and ISO dates and times, including
  timezone, in various DCMTK classes, e.g. a default time zone ("+0000")
  is not added any more, if no value is specified.  Furthermore, the
  fractional part of a second is now also supported when reading/writing
  time and date/time values from/to XML input/output in an SR document.

- Added MDC (Mapped Diagnostic Context) filter to oflog.  MDC allows for
  attaching information to threads in the form of key/value pairs.
  Logging can then be configured to match ("filter") on these key/value
  pairs in order to decide whether the thread at hand should log, and
  how.

- Various TLS enhancements:

  - Adapted DCMTK for use with OpenSSL 4.0.x.

  - Added TLS support to the command line tool wlmscpfs.

- Removed the deprecated support for the C++98 language standard.  Now,
  at least C++11 is required.  Furthermore, enabled the use of the STL
  (Standard Template Library) features by default, instead of DCMTK's
  historic fallback implementations.  The fallback implementations are
  still available, though (see INSTALL file for details).

- CMake-related enhancements and other changes to the build system:

  - Added CMake variable DCMTK_EXTERNAL_MODULES to allow adding external
    modules to DCMTK without having to copy files into the DCMTK source
    tree.

  - Added DCMTK_WITH_SANITIZERS (CMake) and --enable-sanitizers
    (Autoconf) to build with AddressSanitizer (plus LeakSanitizer on
    Linux).

- Pre-built binaries for Windows (x86_64 and x86), macOS (arm64) and
  Linux (x86_64) are now created automatically on GitHub, for each
  release as well as a "latest" development snapshot.  They can be
  downloaded from https://github.com/DCMTK/dcmtk/releases.

- Fixed various other issues that occurred after the official 3.7.0
  release, and further improved the performance.  See CHANGES file for
  details.


Many people have contributed to this new release of DCMTK, appearing
here in alphabetical order.  Thank you very much for your support!

  'elp3pinill0'
  Abhinav Agarwal
  Andras Lasso
  Andrey Fedorov
  Arash Ale Ebrahim
  Arjun Basnet, Securin
  Bradley Lowekamp
  Carlo Pastorino
  Christian Wetzel
  Cristhian Daniel Rivas Zúñiga (Instituto Tecnológico de Costa Rica)
  Dan Wolff
  Daniel Birtwhistle
  Daniel M. Drucker
  David Clunie
  Dominik Blain
  Eneshan Erdoğan Karaca
  Evgeny Sabelskiy
  IN-CYPHER OSS Security Team
  Jiami (DMSAN)
  Kaixuan
  Kamal Sentassi (S9S Security Electronic Service)
  Kyle Sunderland
  Lei Meng
  Machine Spirits UG (haftungsbeschränkt)
  Mathieu Malaterre
  Matthias Deeg (SySS GmbH)
  Michael Halle
  Naavin Ravinthran
  Peter Klotz
  Phil Martel
  Pino Toscano
  Piotr Batko
  Samuel Paschuan (4nt1, xmartlab)
  Sebastian Andres Muñoz Morera (Instituto Tecnológico de Costa Rica)
  Sjors Gielen
  Tristan Madani
  Vladimir Poluchaevskiy
  Yiyi Wang
  glitchfox (Benjamin Ali)
  quellsec.dev
  Yuxiao Yan
  Zhanglinghang

  GitHub users "luk1337", "MarkLee131", "mrbean-bremen", "nutzlastfan"
    and "Vogtinator"

Members of the DCMTK Team who have worked on this release are:

  Joerg Riesmeier <dicom@jriesmeier.com>
  Harald Roesen <harald.roesen@offis.de>
  Marco Eichelberg <eichelberg@offis.de>
  Michael Onken <onken@open-connections.de>
  Tingyan Xu <tingyan.xu@offis.de>

The DCMTK software can be downloaded via:

  https://dicom.offis.de/dcmtk or https://www.dcmtk.org/

OFFIS e.V., Oldenburg, Germany, 2026-10-15