v1.5.5

Added

• Add an in-memory handler overload of itkimage2dcmSegmentation (convert without going through disk) (5074f43, @rfloca)
• Add back-filled CHANGELOG.md and release-notes tooling (24c5f45, @fedorov)

Changed

• Designate a labelmap's background via Pixel Padding Value (0028,0120) instead of an inserted Background segment; this emits Pixel Padding Value on write and drops the labelID 0 read entry that shifted segment metadata in 3D Slicer (#541, @michaelonken)
• Allow gapped labelmap segment numbers with --useLabelIDAsSegmentNumber, reject colliding label IDs across inputs, and size bit depth from the highest segment number (fixes #537) (#541, @michaelonken)
• Address SonarCloud findings: drop redundant c_str(), use is_same_v (145b7b4, @rfloca)
• Remove noisy console output (3e32642, @fedorov)

Fixed

• Fill missing labelmap slice positions with the Pixel Padding Value (or 0, with a warning) instead of refusing the conversion (#541, @michaelonken)
• Fix ReDoS-prone regexes in changelog generator (SonarCloud S5852) (a29753b, @fedorov)
• Validate and tighten macOS dependency cache usage in CI (2dea14e, @Copilot)

Build & dependencies

• Bump DCMTK (5708ba6) so the designated labelmap background drives both the Background segment and Pixel Padding Value on write, as required by #541 (bedc18d, @michaelonken)

Full set of changes