The GPU export now runs the same upscaler in half precision. The chip is handed 2.34MB of weights instead of 4.88MB, and where its shaders can multiply in fp16 it does twice the work per pass. `realesr-fp16.py` is the conversion, run on what `realesr-gpu.py` already wrote (the PReLU-rewritten model), never instead of it. onnxconverter-common's `keep_io_types` needed two of its own mistakes put right: - It rewrites the consumers of the graph input but misses the one that never goes through the network. This model adds a Resize of the ORIGINAL photo to the upsampler's output, that Resize reads the graph input directly, and the runtime refuses a graph whose final Add mixes fp32 and fp16. The consumer is rewired onto the cast that `keep_io_types` should have sent it through. - It also half-precisions Resize's `scales` — ONNX defines that input as float32 whatever the rest of the graph does, and a runtime that opens the file at all rejects the whole graph: "Type 'tensor(float16)' of input parameter (/Constant_output_0) of operator (Resize) is invalid", on the GPU as much as on the processor. The script widens it back and asserts it did. The tensor the app builds stays float32 and the model's two Cast nodes are its own edge, so nothing in superRes.ts or App.tsx has to know which copy it got: 205 nodes, 101 fp16 weights, io still float. `openSession` asks for the model only where the adapter advertises `shader-f16` — a provider without it emulates the type on the same file at the same speed, so the smaller download would be the only thing gained. The order is fp16 on the GPU, fp32 on the GPU, fp32 on the processor, each attempt falling through on its own failure. Measured on the rebuilt container (BASE=http://localhost:8090): - fp16 vs fp32 on a 128x128 tile, same graph: max abs diff 0.0025 (0.65/255), mean 0.00028, psnr 71.0dB. - sr-f16-chooser.cjs 4 PASS / 0 FAIL: on a forged adapter advertising `shader-f16`, the fp16 file is the FIRST model asked for; on one whose device refuses, the fp32 file is fetched for the processor and the 4K export still lands (7,555,377 bytes, 19.6s), no console errors. - superres-test.cjs 32 PASS / 0 FAIL, sr-crop-export.cjs 0 FAIL, web-smoke.cjs 0 FAIL, sr-model-probe.cjs 0 FAIL. - npx tsc --noEmit clean. ponytail: the speed of the fp16 path is NOT measured — this container has no WebGPU adapter (not even lavapipe/swiftshader, headed through xvfb), so every export here runs the wasm fallback. sr-model-probe.cjs on a machine with a GPU is what would show it. Also worth noting for the next person: in a browser with no working adapter, the runtime builds the device BEFORE it fetches the model, so no probe in a GPU-less container can observe which model was chosen — a stub whose device throws leaves the network silent. The chooser probe forges a device good enough to be accepted for exactly that reason.
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.