• About Weasis
• Getting Started
• Release History
• Build Weasis
• General Features
• Connectivity & Interoperability
• Viewer Features
• Security & Quality
• Community and Support
• License

Weasis is a powerful, multifunctional, and open-source DICOM viewer designed for both standalone and web-based use. It excels in medical image visualization and is widely used by healthcare professionals and research institutions. Engineered for seamless integration with PACS and DICOM workflows, Weasis offers a reliable solution for modern medical imaging needs — from routine reading to AI-assisted review and quantitative imaging.

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• General information
• Getting Started
• Download binary releases
• Live Demo with different datasets

See CHANGELOG

See How to build Weasis

• Open source DICOM viewer under EPL 2 or Apache 2 license
• Flexible integration with PACS, VNA, RIS, HIS, or EHR (see integration documentation)
• Desktop distributions (Windows, macOS, and Linux)
• Web access through the weasis protocol
• Responsive user interface working well on high-DPI screens
• Multi-language support (20+ languages)
• Configuration of preferences on server-side and client-side, multi-level overrides (default → workstation → user)
• API for building custom plug-ins via the Weasis plug-in archetype
• Embedded DICOM viewer in CD/DVD or other portable media
• Dicomizer module to convert standard images, videos, PDFs and STL meshes into DICOM files
• AI-assisted and quantitative imaging workflows

Weasis supports every common DICOM transport and authentication standard, fitting into existing clinical infrastructure — PACS, VNA, EHR, RIS, and HIS — in two complementary ways:

• Server-side, via a gateway such as ViewerHub — recommended for clean, centralized integration: the gateway brokers PACS / DICOMweb access, handles authentication and manifest generation, and exposes a single endpoint to the viewer.
• Client-side, by configuring DICOM nodes and DICOMweb sources directly in Weasis — useful for standalone workstations, smaller sites, or when no gateway is available.
• Classic DIMSE — Query/Retrieve (C-FIND, C-GET, C-MOVE) and Store (C-STORE).
• DICOMweb — QIDO-RS, WADO-RS and STOW-RS over HTTPS, configurable per source.
• WADO-URI — for legacy PACS servers and the Weasis manifest flow.
• weasis:// protocol — single-click launch from browsers, EHR and RIS portals.
• Authentication — Basic auth, OAuth 2.0 and OpenID Connect (Authorization Code with PKCE and loopback redirect, RFC 8252) — works against Keycloak, Google Cloud Healthcare and any compliant OIDC provider.
• Send / Export — store to a PACS or DICOMweb server (C-STORE or STOW-RS), or export locally as DICOMDIR ZIP, ISO with the Weasis CD viewer embedded, JPEG, PNG, TIFF, AVI / MP4.
• Integration hooks — argument-driven launch, manifest-based study loading, downloadable manifests with WADO; documented contracts for EHR / RIS / HIS integration.

• Data type support

  • Display every common DICOM file including multi-frame, Enhanced (CT / MR / US Volume), MPEG-2, MPEG-4, MIME Encapsulation, DOC, SR, PR, KOS, SEG, AU, RT, ECG and Parametric Map (float / double pixels)
  • Modern codecs: JPEG (baseline, extended, lossless), JPEG-LS, JPEG 2000, JPEG-XL, RLE, Deflated Explicit VR Little Endian
  • Import and export DICOM CD/DVD with DICOMDIR
  • Import and export DICOM ZIP files
  • Viewer for common image formats (TIFF, BMP, GIF, JPEG, PNG, RAS, HDR, PNM)

• Exporting data

  • Export DICOM files locally with several options (DICOMDIR, ZIP, ISO image with Weasis embedded, TIFF, JPEG, PNG…)
  • Send DICOM files to a remote PACS or DICOMweb server (C-STORE or STOW-RS)
  • Save measurements and annotations as DICOM Presentation States or XML

• Viewing and image rendering

  • Multi-monitor support with per-monitor calibration, HiDPI, full-screen mode
  • Image manipulation with mouse buttons (pan, zoom, windowing, rotation, scroll, crosshair) and customizable keyboard shortcuts
  • DICOM Modality LUTs, VOI LUTs, LUT Shapes, and Presentation LUTs (including non-linear)
  • DICOM Presentation States (GSPS) — applied with graphics rendered as overlays
  • DICOM Overlays, Shutters and Pixel Padding
  • Lossy compression indicator in the information layer so the user knows the source quality, messages when geometry issues are detected (inconsistent pixel spacing, slice spacing, or orientation across the series)
  • Per-view synchronization with explicit overrides and FrameOfReferenceUID-aware grouping (orphan views are excluded from auto-sync to prevent comparing unrelated anatomy)

• Advanced imaging

  • Oblique Multi-Planar Reconstruction (MPR) with gantry-tilt correction (backward mapping + trilinear interpolation) and 3D matrix transformations for non-standard patient positioning
  • Curved MPR (CPR): trace a curve on the axial plane — typically the dental arch on a cone-beam CT — to build a panoramic view and cross-sectional slices
  • Maximum Intensity Projection (MIP / MinIP / Mean IP) available in the 2D, MPR and 3D views
  • 3D Volume Rendering with presets, custom Volume LUTs, and segmentation modes including masks that keep or remove the voxels inside the segmentation
  • DICOM Segmentation (SEG) overlay in 2D, MPR and 3D, with per-region visibility, color, opacity and statistics
  • PET/CT fusion: overlay a PET or SPECT series on its CT / MR base, with SUV display window and color scale
  • 4D / multi-phase series: automatic dialog to split a multi-phase series into per-phase sub-series for MPR, MIP and VR
  • Cross-lines, 3D cursor
  • Persistent magnifier glass
  • Layouts for comparing series, studies or modalities side-by-side

• Measurement and annotation tools

  • Length, area, angle (incl. Cobb), perpendicular, parallel and free-shape
  • Region statistics of pixels (Min, Max, Mean, StDev, Skewness, Kurtosis, Entropy)
  • Histogram of modality values
  • SUV measurement (PET / nuclear medicine), also on a fused PET/CT view
  • Volume and voxel count of segmented regions
  • Pixel-info inspector (raw value, modality value, presentation value)

• Specific viewers

  • DICOM ECG: display all the DICOM waveforms and allow measurements
  • DICOM SR: structured report viewer with hyperlinks to images and associated graphics
  • DICOM AU: audio player (allow to export to WAV files)
  • DICOM RT: structure-set, dose distribution and DVH viewer

• Other tools

  • Printing views to DICOM and system printers
  • Apply and Create DICOM Key Object Selection by selecting images with the star button
  • Display and search across all DICOM attributes
  • Acquire / Dicomizer: capture or import non-DICOM media (images, videos, PDFs, STL meshes) and convert into DICOM, with video size validation and per-modality presets

• Authentication & transport — OAuth 2.0 / OpenID Connect for resource-server access; HTTPS for transport; code-signed installers.
• Supply chain — SBOM-tracked dependencies, continuous CVE monitoring.
• Test coverage — unit and integration tests pin the most sensitive parts (DICOM decoding, identity model, pixel/LUT pipeline, measurement statistics, anonymisation, authentication, view synchronisation).
• Static analysis — every build is scanned by SonarCloud for reliability, maintainability and security ratings, with quality-gate status enforced on the main branch (see badges at the top).
• Upstream libraries — weasis-core-img and weasis-dicom-tools maintain their own ISO 14971-style risk-coverage matrices, cited from this repository's verification index.

Weasis encourages community participation. Whether you're reporting bugs, suggesting features, or seeking help, you can connect with others here:

• GitHub Issues
• Forum: Google group or GitHub Discussions
• Frequently Asked Questions
• Contributing guide

Weasis is dual-licensed under the EPL 2.0 and Apache 2.0.