BLACK at full deflection returned a soft picture, and on a monochrome frame it
returned the blurred base outright. The tone pass reads the ramp at the
neighbourhood's base and then rebuilds the pixel, and it rebuilt it by the RATIO
the base had moved by — `Base' * (Input / Base)`, the other half of
fix_shadow.md's decomposition. A ratio is a gain, and that gain is a function of
the neighbourhood: the knob that takes the base toward zero scales every pixel's
detail by the same coefficient, so the knob that darkens the frame takes its
texture with it. Measured on lightroom_shadow.jpg at 1024px through tone-sim.mjs,
the pass in plain JS with the shader's own constants: at BLACK -100 the finest
gradient came back at 0.75 of the input under the ratio and at 0.98 under the
sum, while the frame darkened the same either way (mean 0.416 to 0.359 both). A
monochrome stock is the whole frame of that error, because all three channels ARE
the pixel's luma there, which is why the picture came back as the base — soft,
and short of every edge it had.
The reconstruction is `Base' + Detail`, ADDED and not scaled, and it costs
nothing where there is no move to make: with every knob on zero the ramp at the
base IS the base, so the difference is exactly zero and the pass is the identity
however coarse the base is. A caller that hands in no neighbourhood at all — a
mask — hands in the pixel's own image as its base and gets the global move back,
which is what the ratio gave it too. `o` is held inside the cube before the
detail is added, so a neighbourhood the ramp has pushed under the floor keeps the
structure around it instead of carrying its pedestal down onto every pixel in the
region. The bright side of the same move is untouched: the lift is still the
neighbourhood's, and at SHADOW +100 the band above the lifted knot still keeps
0.81 of its spread where the global move kept 0.42.
CLARITY drew a light stroke down every contour, and the reason was in what the
blur called a neighbour. The range weight was the colour difference,
`exp(-dot(d, d) * 24)`, which is loose on any coloured edge — two sides of a hair,
a branch or a rail can share a red and differ in green — so the reference reached
across the edge, and the reference is exactly what the blend subtracts. The wider
it reaches, the more a contour reads as detail. It reads LUMINANCE now, one
decision per tap at the doc's own scale (`CLARITY_RANGE_SIGMA` = 0.04), so an edge
of any hue stops the blur dead.
The blend moved the three channels by their own differences, which is what
coloured fringing along every contour was, and the amount it moved them by was
the MASK's `CLARITY_GAIN` borrowed for a different child. It moves LUMINANCE now
— one value carries the whole pixel back with it, so hue is untouchable and skin
does not go sallow at the top of the knob — under the doc's midtone weight
M(L) = 4L(1-L), which deepens the greys a picture is made of and leaves the burnt
ends and the deepest shadows where they are. The positive side's gain lives
inside the shader (4.5, raised from the doc's 1.8 because the range weight above
reaches less far and carries less detail): clarity-halo.mjs, which measures the
pass pushing a pixel outside the range of its own neighbourhood, reads a bright
stroke of 55.3/255 on lightroom_shadow.jpg and 54.3/255 on DSCF1701.JPG at +10,
against the old pass's 145 and 127 at the same knob — and 8.0 already reads 98, so
the knob does not need to go further to keep the flat areas moving.
`exportEngine` passes the knob's own units now, `[clarityKnob / 10]`, since the
gain and the sign are the shader's business and the mask's gain is not the
frame's.
And a backup folder the browser had stopped letting the page write to wrote
nothing and said so, once, with no way back: a permission outlives the tab only
while the tab does, so the row kept reading a permission of a moment ago while
the write went to the disk without one. A refusal that names the permission, or
the folder that is not there, now goes through the picker ONCE — the picker is
the only thing that hands a folder back — and the run is repeated; anything else
is the folder itself saying no, and is not asked twice. The sentence on the
screen is one line over a strip of photographs and cannot carry a reason, so the
reason goes to the console and a word of it into the note (`{why}`, the name the
browser gave the refusal and never a stack), which is the whole of what tells a
folder that was moved from a permission that lapsed. Both dictionaries learn the
word.
Checked: `tsc --noEmit` clean; `tone-base-check.mjs` and `highlight-knee-check.mjs`
updated to the new reconstruction and passing; `tone-sim.mjs` on
lightroom_shadow.jpg at 1024px for the numbers above; `clarity-halo.mjs` for the
stroke.
RecipesCam
RecipesCam is a camera and photo-editing app built around recipes — reusable
looks that carry a film simulation plus a full set of adjustments. You shoot or
open a photo, dial in a look, and keep it as a recipe you can apply again, share
as a .recipe file, or save to your account.
It ships twice from one repository: a React Native (Expo) app for iOS and
Android, and a self-contained web build under docker/ that runs the same
render pipeline in the browser.
What it does
- Shoot with a recipe applied. Live viewfinder, GPS-tagged captures, and the recipe baked into the saved file.
- Film simulations. Built-in looks — PROVIPES, VELVIPES, CLASSIC CHRIPES, CLASSIC NEGIPES, ASTIPES, ETERNIPES, ACRIPES, B&W HIGH CONTRAST and the LC STREETLIFE pair — each with its own grain and tone curve.
- The full adjustment set. Exposure, contrast, highlights and shadows, saturation, colour temperature, clarity, grain, and an HSL mixer with a colour picker that samples straight off the photo.
- Geometry. Crop to a fixed ratio or free-form, quarter turns, and a straighten ruler, plus printed frames (classic border, retro instant, wall frame portrait/landscape).
- Finishing. Watermark and GPS stamp, EXIF carried through the export, JPEG written with a proper 300 DPI JFIF header.
- On-device upscaling. A Real-ESRGAN pass runs locally when an export asks for more pixels than the source has — no server sees the photo.
- Recipes. Save, favourite, export and import
.recipefiles; the web build keeps them in your account, the phone build also keeps them on device.
The two builds
| Build | Where | Stack |
|---|---|---|
| iOS / Android | repo root | Expo + React Native, @shopify/react-native-skia for the render pipeline, NativeWind for styling |
| Web | docker/ |
Vite + React, CanvasKit (canvaskit-wasm) for the same pipeline, Fastify + SQLite API for accounts and recipes |
The render engine is shared by design: the web build compiles the app's own
src/utils/* and type definitions unchanged, with @shopify/react-native-skia
aliased to a CanvasKit shim (docker/frontend/src/engine/skiaShim.ts). A look
looks the same on both because it is the same code.
Running the web build
cd docker
cp .env.example .env
docker compose up -d --build
# → http://localhost:8090
Photos never leave the browser: grading, framing, watermarking and JPEG
encoding all run in the visitor's tab; the API only stores accounts and recipe
JSON. See docker/README.md for the layout and the proxy setup.
Running the app
npm install
npx expo start # Expo Go / dev client
npx expo run:android # or run:ios for a native build
Repository layout
App.tsx, src/ the Expo app: screens, tool rail, viewfinder, shaders
docker/ the web build (frontend + API + compose file)
frontend/shared/ vendored copies of the app's types and utils
frontend/src/engine/ CanvasKit shim, export engine, super-resolution
docs/ privacy policy
THIRD_PARTY_NOTICES.md licences of the bundled fonts, models and libraries
Licence
See LICENSE and THIRD_PARTY_NOTICES.md.