A hot photosite went into the demosaic as it was read, and came out as a coloured cross three pixels wide that nothing later could take back out. Night and long exposures showed them; the defect-map reader added for FR-RAW-3 was never wired in, and a CR2 carries no map anyway. A pass over the mosaic now runs ahead of the demosaic, into a second buffer. A photosite is hot when it reads more than twice every same-colour photosite in its 5x5 window plus 2% of the range, and more than twice each of its eight immediate neighbours of any colour. The second half keeps stars and glints: real light reaches the sensor through a lens and an anti-aliasing filter and lights a patch, so the photosites beside it are lit too, where a hot photosite's are dark. It is replaced by its brightest same-colour neighbour, which invents nothing. Dead photosites are the mirror case, judged only where the neighbourhood is above 5%, so shadow noise clipped at black is left alone. The colour of each photosite comes from a 6x6 sensor-anchored tile, so Bayer and X-Trans share the pass. Export and every other path that demosaics get it too, and there is no setting: the repair only fires where a single photosite disagrees with everything around it. Cost, warm, on a Canon 6D frame (RTX 3050): 91-99 ms to demosaic before, 94-98 ms after; the extra pass is inside the run-to-run noise. Tests render a frame with and without the defect and compare the finished pixels. Without the repair a hot photosite showed by 230 and a dead one by 168; with it neither shows, and a 3x3 highlight at white survives.
Documentation
Two audiences, two folders. Most people want the first table and never the second.
Using DarkRoom
| The manual | Every feature, pictured from the application itself — opening a library, rating, labelling and filing, duplicate originals, developing, local masks, repair, film, presets, panoramas, export and albums. The application carries it and opens it from Help and from Settings |
| How it is driven | Every gesture and shortcut, by screen. Generated from the code, so it cannot describe one the application does not have. The same list is the in-app help sheet: Help or F1 in the grid, ? or F1 in develop |
The top-level README says what DarkRoom is, how to get it on each platform, and what is still missing.
Changing DarkRoom
Everything under dev/ is for someone working on the code. Start with
CONTRIBUTING.md, which says how to land a first change
without reading the rest.
The register and the record. What must be built, how it is built, and how far along it is.
| requirements.md | What the software must do — the numbered register, the decisions (D-numbers) and the spikes (S-numbers) |
| architecture.md | How it is built — crates, the GPU pipeline, the data model, sync |
| traceability.md | Generated: which requirement is claimed by which file. Never edited by hand |
| outstanding.md | What is specified and not built, and whether that is a decision or a gap |
| technical-debt.md | Compromises taken deliberately, each with the condition that retires it |
| code-health.md | What a contribution costs, per seam, measured |
Designs, one per subsystem. Each is the specification the code was built to, kept current as the code moved.
| catalog.md | The index, the library view, incremental scan, the job queue |
| storage.md | Storage backends: the seam a folder, a sync client and a Nextcloud account share |
| faces.md | Face detection, identity, clustering and the eye-state models |
| segmentation.md | How the application finds the regions a local mask snaps to |
| mask-editing.md | Painting, erasing and combining masks |
| spot-removal.md | Clone and heal as parameters in the edit graph |
| panorama.md | Alignment, projection, the chunked composite and the border fill |
| inference.md | The neural runtime and model chosen per device, with the measurements |
| display-and-extension.md | The display contract, and why the fused pipeline is already most of a plugin format |
| view-composition.md | A controller for the display layer |
| ui-navigation.md | Finding things in the interface once there are many |
Measurements. Numbers committed so a regression is a diff rather than a recollection.
| benchmarks.md | The per-commit suite: what it covers, what it does not, how to read a failure |
| bench-baseline.json | The committed numbers the suite checks against |
| frame-budget.md | What a frame costs on each device, and the decision those figures settled |
Platforms and distribution.
| distribution.md | Which channels v1 targets and what each one constrains |
| windows.md | The Windows installer, cross-built from the Linux CI |
| android-signing.md | Which key signs the APK, and keeping it |
Archive. Kept as the record of what was asked for, not as plans.
| milestone-v0.1.md | The first milestone, delivered 2026-08-30 and superseded |
| ui-refinement.md | How the interface should look; succeeded by ui-navigation.md |
Conventions
Three files here are generated and must not be edited by hand:
gestures.md, dev/traceability.md and manual/index.html, the page the
packages install, rendered from manual/README.md. All three come from
cargo run -p traceability, the pre-commit hook keeps them in step with the
tree, and CI fails when one is not what the tree generates. The manual's
pictures are recorded by tools/manual and live
in LFS.
A design document links to the requirements it satisfies and to the code
that satisfies them. When the code moves, the link moves with it; a document
that has stopped being true goes to dev/archive/ with a note saying what
replaced it, rather than being deleted.