The knob was a `MakeBlur` image filter on the draw of the graded photo — one
sigma over all three channels — so at NOISE REDUCTION 100 a 1024-pixel preview
lost every edge finer than 0.6 of a pixel of its own and nothing brought the
luminance detail back. That is thay_doi_thong_so_giong_lightroom.md §4's own
warning ("Noise Reduction sẽ làm nhòe toàn bộ chi tiết sợi tóc và vân da") written
into the engine, and the filter had a second cost: a paint filter is handed the
shader's INPUT, so the pass could never read the graded pixels it was supposed to
correct.
It is a two-child pass now, NR_SKSL, run after the draw: the frame, and a blurred
copy of it (blurredFrame — the snapshot read back through the same MakeBlur the
ramp's base and the negative sharpening use). The output takes its CHROMA from
the blurred child and its LUMA from the frame, the split the tone ramp's header
already describes (`rgb - luma`), so the output's brightness is the input's at
every amount by construction — the eye is nearly blind to a hue change at that
scale, which is the whole reason the colour half is free. The reference reaches
NR_CHROMA_SPAN = 0.4% of the frame's width, the doc's own 3..5 pixels of a
full-resolution frame, where the knob's blur was 0.6 of a pixel.
The luminance half of §4.1 (its bilateral filter) is deliberately not here: it is
the half that costs detail and no frame has shown grain the colour half left
behind. ponytail: add it as a second child of this same pass when one does.
Checked: `tsc --noEmit` clean; `denoise-check.mjs` (new) compiles NR_SKSL on
CanvasKit, asserts the engine still wires both children and no longer blurs the
draw, and renders the pass at five amounts against a flat pair — amount 0 is the
pixel exactly, amount 1 carries the neighbourhood's colour difference, and the
luma never moves at any of them; `highlight-knee-check.mjs`, `tone-base-check.mjs`
and `mask-wb-check.mjs` still green.
RecipesCam web — self-contained stack
A Docker-hosted web build of RecipesCam. Everything it needs is in this folder: move it to another machine, run two commands, and the app is up. It does not need the React Native project around it.
cp .env.example .env
docker compose up -d --build
# → http://localhost:8090
What runs where
| Service | Image | Role |
|---|---|---|
frontend |
nginx:1.27-alpine (built by frontend/Dockerfile) |
Static SPA + /api/ reverse proxy |
api |
node:22-slim (built by backend/Dockerfile) |
Accounts + saved recipes, SQLite on ./data |
frontend resolves api through Docker's embedded DNS and proxies /api/* to
it — that is why the API container is named api and why it is not published on
the host. Only ${WEB_PORT:-8090} is exposed.
Photos never leave the browser. The CanvasKit render pipeline (grade, frame, watermarks, JPEG encode) runs in the visitor's tab; the API only stores recipes as JSON.
Layout
docker-compose.yml the stack
.env.example WEB_PORT
data/ SQLite (created on first run, gitignored)
backend/ Fastify + better-sqlite3 API, own Dockerfile
frontend/ Vite + React + CanvasKit SPA, own Dockerfile + nginx.conf
shared/ vendored copies of the app's types + utils (see below)
src/engine/ skiaShim.ts (CanvasKit) + exportEngine.ts (render pipeline)
+ session.ts (localStorage/IndexedDB studio persistence)
Vendored files
frontend/shared/{types/index.ts,utils/*.ts} are byte-identical copies of
src/types/index.ts and ten src/utils/*.ts files from the React Native
project (@shopify/react-native-skia is aliased to src/engine/skiaShim.ts in
vite.config.ts + tsconfig.json, so those files compile unchanged):
cinemaShader colorUtils defaultRecipes exifWrite frameUtils jpegDpi
paramDefs recipeShare skiaImage toneShader.
The landing page needs no CDN: frontend/public/assets/fonts/*.woff2 are the
seven self-hosted faces behind the three font groups the Themes menu offers
(Plus Jakarta Sans / Inter / JetBrains Mono, Fraunces / Be Vietnam Pro /
Courier Prime, Be Vietnam Pro / Space Mono — all SIL OFL, pulled from Google
Fonts, vietnamese + latin + latin-ext subsets), and
frontend/public/assets/samples/s*.jpg are the six placeholder negatives the
film strip, preset tester and QR card show (swap them for real graded stills
whenever we have them). Its one foreign request is the QR image from
api.qrserver.com, which degrades to an empty slot offline.
When the app changes one of them, copy it back in — the renderer is only "parity" for as long as these stay in sync:
cd <repo>/docker/frontend/shared/utils
cp <repo>/src/utils/<name>.ts .
Operations
docker compose logs -f api # API log
docker compose restart api # after backend/src changes (rebuild: --build)
docker compose down # stop; ./data survives
Backup is the ./data folder — that is the whole database.
Checks
curl -s http://localhost:8090/api/health # {"ok":true}
curl -sI http://localhost:8090/ # 200, index.html
Then open the UI, drop a photo in, and confirm the preview shows the picture and
EXPORT downloads a JPEG that opens. The preview going solid black while the
export still reports a plausible size is the one failure mode worth knowing: it
means the CanvasKit GPU surfaces lost their shared GrDirectContext (see
frontend/src/engine/skiaShim.ts), and with no GPU the raster fallback renders
the same pipeline correctly, just slower.