DICOM and pixel support

v0.2.12 separates object discovery from display capability. A recognized DICOM object can be renderable, metadata-only, or controlled unsupported without making the wider scan or server unusable.

Capability is not conformance

These states describe what dcmview can inspect. They are not a DICOM conformance statement, diagnostic-fidelity claim, or clinical validation.

File support states

State	Meaning
renderable	The current pixel layout and transfer syntax have a supported display path.
metadata_only	The object remains available for tags and references, but no display frame is available.
unsupported	The object has pixels, but the current syntax, numeric layout, geometry, or photometric interpretation is outside the display contract.

The registry includes a stable machine-readable support reason where applicable. A frame request for missing pixels returns 404; unsupported transfer syntax or raw component layouts normally return 422. Decode failures are request-scoped and do not stop later requests.

Qualified transfer syntax paths

Transfer syntax	v0.2.12 display behavior
Implicit VR Little Endian, Explicit VR Little Endian, Explicit VR Big Endian, Deflated Explicit VR Little Endian	Native samples are decoded, presentation processing is applied, and a PNG is returned.
JPEG Baseline (1.2.840.10008.1.2.4.50)	Decoded server-side and PNG-encoded.
JPEG Lossless (.57, .70)	Decoded server-side and PNG-encoded.
JPEG 2000 Lossless (.90)	Decoded server-side and PNG-encoded.
JPEG-LS Lossless (.80)	Lossless grayscale decoded through statically linked CharLS and PNG-encoded.
JPEG XL Lossless (.110)	Lossless 8-bit RGB decoded server-side and PNG-encoded.
RLE Lossless (1.2.840.10008.1.2.5)	Annex G/PackBits planes are decoded and supported monochrome, RGB/YBR, or palette layouts are PNG-encoded.

JPEG Extended 12-bit (.51), JPEG-LS Near-Lossless (.81), JPEG 2000 lossy (.91), JPEG XL variants (.111, .112), and prepared HTJ2K cases (.201, .203) are controlled unsupported in the v0.2.12 qualification policy.

Native pixel and presentation scope

The native display path covers one-bit and 8/16/32-bit monochrome integers, Float Pixel Data, Double Float Pixel Data, supported RGB planar configurations, YBR_FULL, YBR_FULL_422, and supported eight-bit palette color. Pixel aspect ratio is derived from Pixel Spacing when possible, then Pixel Aspect Ratio.

For supported layouts, v0.2.12 can apply stored-bit interpretation, rescale slope/intercept, modality and VOI LUTs, DICOM LINEAR windowing, MONOCHROME1 inversion, pixel padding, embedded overlays, rectangular display shutters, and selected ICC-profile preservation. Server PNG and safe browser raw rendering follow the same presentation convention.

ICC preservation does not claim a numeric color-management transform or optical-path-specific profile selection.

Object-family behavior

• Classic, enhanced, visible-light, ordinary multiframe, and qualified RT Image objects use generic pixel inspection when their pixel layout is supported.
• SEG, Parametric Map, and RT Dose default to stored-pixel preview with separate declared semantic context.
• WSI shows decoded, positioned individual tiles; it does not stitch a Total Pixel Matrix.
• Presentation states, registrations, structured reports, key objects, waveforms, encapsulated documents, and non-image RT objects can remain available for metadata and reference navigation without an inferred renderer.
• DICOMDIR is recognized and skipped. The file-set hierarchy is not parsed.

v0.2.11 compatibility qualification

The frozen 2026-08-28 campaign exercised 169 valid objects, one legacy object, 15 negative cases, 139 stress files, and 24,465 deterministic fuzz target operations without crashes, timeouts, unacceptable outcomes, or failed required assertions in the resolved evidence. The valid runner still recorded 37 explicit unverified outcomes where its base evidence did not establish a broader claim.

The campaign is reproducible compatibility evidence for research inspection, not a DICOM conformance certificate. Current limits include conservative semantic geometry, positioned-tile-only WSI, controlled unsupported syntaxes, no DICOMDIR hierarchy, and reduced stress baselines without reviewed hard thresholds.

See semantic objects and WSI for the difference between pixel preview and declared context.