Commit Graph
8 Commits
Author SHA1 Message Date
dtourolle 95c9cffc0d Keep the embedder off the Hexagon, and let the probe example ask for a runtime
On the tablet the engine compiled arcface for the NPU: the routing
compared the form a rung wants with the form on offer, and for the
embedder both are f32, so nothing said no. A rung now says which roles
it serves at all, and the Hexagon does not serve the embedder (§7 —
its vectors must compare across devices). Tested at the routing seam.

dr-segment's onnx_probe example still named ort-tract, which is what
stopped the workspace test build.
2026-09-19 16:21:53 +02:00
dtourolle 42d11d919b cargo fmt and clippy across the panorama work, and one lint master carried
The dr-face comparison is master's: a negated partial-order test on the
eye box's width, rewritten as the two conditions it meant.
2026-09-19 15:53:06 +02:00
dtourolle e4b6b6c935 S15.2: XFeat exports at a fixed shape and loads under tract
tools/export-xfeat.sh exports the convolutional network alone at 768×1024
grayscale, on the pattern of export-seg-model.sh: thirteen standard
operator types, no dynamic axes, the keypoint decoding left to Rust.
examples/onnx_probe loads it through the ort-over-tract backend the app
ships with nothing unsupported and runs it in ~300 ms on the desktop CPU.

The weights are Apache-2.0, read from the repository's LICENSE, with no
grant on the checkpoint — recorded in models/LICENCE.md before they land,
as FR-MRG-8 asks. The probe stays: the next model will need the same
check.
2026-09-19 15:24:10 +02:00
dtourolleandClaude Opus 5 f87bf6ebc0 Charge a colour mode for its rarity, and keep the verdict
The refinement worked and could not be controlled. Pruning modes below a
share threshold made the flag's removal a *discrete* event: below the line
its Mahalanobis distance was enormous and nothing rescued it, above the line
it sat at zero and nothing removed it. A control over that would appear dead
through most of its travel and then start eating sky.

So the prune is gone. A mode is charged `−ln(share × k)` nats, floored at
zero, and that cost enters both tests — doubled in the chi-square, which is a
squared distance, and directly in the log density. Rarity becomes a distance
rather than a threshold, and the things a photographer wants to remove
separate along it.

Measured on the synthetic frame the tests build: a flag holding 1.6% of the
sky is more than half gone by **2.95 nats** and a cloud bank holding a third
of it survives to **5.75**. The whole interval between them is somewhere a
control can sit. `the_flag_goes_before_the_cloud_does` pins the ordering,
which is the property that makes one slider worth offering at all.

Measured against an even split rather than against one, so raising
`clusters` describes a category more finely without making every colour in it
look rarer. Floored at zero so a dominant mode earns no *discount* — a
bonus there would let the commonest colour outvote a bad chi-square, which is
the one direction this must not bend.

`Refinement` holds the per-pixel verdict, quantised to a byte over ±16 nats —
an eighth of a nat per step, far finer than the narrowest transition the gate
can be asked for, and the same size as the coverage buffer it sits beside.
`apply` is then a smoothstep, and the model is never consulted again.

That is `distance.rs`'s arrangement deliberately: there a signed distance
field is computed once and feather, grow and shrink become arithmetic on it,
"which is what makes those live controls rather than ones that stall on every
drag". Same shape, different field.

The blur moved with it, from the gate to the verdict. Smoothing the evidence
rather than the decision means it is paid for once in `compute` instead of on
every frame of a drag, and it is the better thing to smooth in any case.

`apply` at `STRICTNESS_OFF` returns the weights untouched without reading the
verdict at all. A control whose off position is *very nearly* the unrefined
mask cannot answer "is this helping"; one whose off position is the unrefined
mask can. `strictness_zero_changes_nothing` holds it to that, and
`strictness_is_monotonic` holds the rest of the travel to only ever removing
more — a slider that gave weight back partway up would be one whose direction
nobody could predict.

The synthetic sky is smooth enough to sit on `VARIANCE_FLOOR`, where a real
one has noise and therefore a real spread, which moves every crossing down
together. The ordering survives that; the placement is a calibration. Which
is the honest argument for a control rather than a constant, and why the
default sits at half scale instead of at the flag's measured crossing.

The example sweeps the whole range and writes a frame per nat, because the
question a photographer asks of a slider is where to put it, and that needs
the travel rather than a point on it.

Verified: fmt clean, clippy -D warnings clean, 60 dr-segment tests.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-30 18:30:40 +02:00
dtourolleandClaude Opus 5 4f4abd335f Cut a scene category back to the pixels that agree with it
A flag in the sky came out weighted as sky, and no feather setting fixed it.

The scene model's logits are `[1, 150, 80, 80]`, so one cell is eight input
pixels; at the 1600px proxy the letterbox scale is 0.4 and **one cell is 20
proxy pixels**, which `rasterise`'s bilinear then spreads across one more
either side. A flag is a handful of cells whose softmax is dominated by the
sky around it. The information was never in the grid, so nothing downstream
of the grid can recover it.

Tiling is the answer for an instance and is not available here: a category
has no bounding box to tile over — sky is wherever the sky is. But the
photograph is at full proxy resolution even though the weights are not, and
it knows exactly where the flag is. So the model says *what*, and the
pixels say *which of them*, which is the division of labour arm C already
draws between the instance model and the watershed.

## Seeds, and why the erosion radius is not a guess

Threshold the weights high, take `signed_distance`, and keep what is more
than 1.5 cells inside. One cell *is* the model's resolution and the bilinear
spreads it across one more, so the band either side of the boundary is smear
rather than evidence. Deriving the radius from `Scene::cell_pixels` rather
than picking a pixel count means it stays right if the proxy edge or the
export changes.

The mirror of that set is a confident *exterior*, free from the same field.

## Dropping small modes is the step that makes it work

Four k-means modes per side, not one Gaussian: sky is blue at the zenith,
white where the cloud is and pale at the horizon, and one blob over all
three rejects two of them.

Then modes holding under 3% of a side are discarded, and without that step
the whole thing fails on the case it was built for. A small flag deep in the
sky has both a high weight and a large distance from the boundary, so it
lands in the interior sample and teaches the model its own colour. It cannot
be excluded geometrically. It can be excluded by share.

Luminance is weighted at a quarter against chrominance for the same reason
the watershed's gradient is. Sky's variance is dominated by luminance, so at
equal weight the distribution is a long bright streak that a mid-grey flag
sits comfortably inside. A flag is separated by chrominance; a cloud is
separated by luminance alone. Not zero, or a dark bird against a bright sky
survives.

## Two tests, because either alone is wrong

Absolute — is this colour plausible under the category, as a chi-square on
the Mahalanobis distance. Comparative — is it likelier inside than outside.
A pixel must pass both.

The absolute test is what catches the flag, whose colour is far from *both*
sides and which the comparative test alone would leave at even odds. The
comparative test is what stops the absolute one needing a constant tuned per
category.

## What this cannot do, written down rather than left to be discovered

An intruder large enough to hold its own mode is kept. By share, a flag over
a fifth of the sky and a cloud bank over a fifth of the sky are the same
object, and colour does not separate them either — a white cloud is as far
from blue sky in chrominance as many intruders are.

So `min_cluster` is not a threshold with a correct value waiting to be
found; it is the trade-off itself, set where a photographic intruder falls.
Both ends are pinned by tests — `a_flag_in_the_sky_is_removed` and
`an_intruder_larger_than_min_cluster_survives` — so that moving the number
reads as moving the trade-off rather than as fixing a bug. The case left
open is a large unrecognised object in a clean category, which wants the
boundary snapped to watershed basins and is a different mechanism.

## Safe to apply without a control

It is subtractive: the output is the input times a factor in `0..=1`. The
worst failure available to it is losing part of a real sky, never gaining a
region, so a blue car below the horizon that was never in the mask cannot be
pulled into it. And a factor in `0..=1` cannot raise a sum, so `scene.rs`'s
partition still holds when every category is refined independently — the
weight taken off the flag lands in the unlisted remainder, which is where a
flag belongs, ADE20K having no class for one.

Every path without the evidence to judge returns the weights untouched and
says which path it took. A refinement that silently did nothing is
indistinguishable from the feature being off, and an empty seed set fitted
to a distribution would reject every pixel.

The signature is deliberately unchanged: categories are addressed by name,
not by index, so a sharper mask cannot create the stale-index hazard the
signature exists to guard against.

The example writes `<prefix>-<category>-refined.ppm` beside the coarse one,
never instead of it — whether this is an improvement is a comparative
judgement and one image cannot answer it.

Verified: fmt clean, clippy -D warnings clean, 57 dr-segment tests.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-30 18:30:16 +02:00
dtourolleandClaude Opus 5 8df6000e4b Decode the scene model into per-category weights
The weights landed last commit with nothing to read them. This is the
decoder, and the shape of it follows from one property worth stating
before the code: the categories must partition the image.

## Why a partition, and not a mask per category

The scene tab applies one grade to every pixel of a category — lift the
sky, desaturate foliage — and both grades meet at the horizon. If each
category carried an independent mask, feathering them outward would make
the boundary band belong to both, so both grades would land there and
every horizon would acquire a visible seam. Feathering has to *blend*
there, not accumulate.

So `marginalise` takes one softmax over all 150 channels and sums within
each category. Grouping cannot change a total of one, so the listed
categories plus the unlisted remainder sum to one at every pixel, by
construction rather than by normalising afterwards. `parse_categories`
refuses a descriptor that claims a class twice, because that is the one
input that would quietly make the property untrue.

## The descriptor is data, and hand-written

`models/scene/categories.txt` groups ADE20K's 150 classes into the eight
a photographer would recognise. It is a file rather than a table in Rust
for the reason `models/LICENCE.md` predicted — a vocabulary is model
metadata — and it is line-oriented with comments rather than JSON like
the `.classes.json` beside it, because that file is generated and this
one is argued. Why `swimming pool` is water and not architecture belongs
next to the line that says so.

Classes are named, not indexed. An index is silently wrong after a
re-export; a name is loudly wrong, and the loader refuses one the model
does not have.

## Resolution, kept visible

`Scene` holds the native 80×80 logit grid and resamples on demand rather
than upsampling once at load. The coarseness is real — it is what the
graph produces — and a type that hides it behind an early resize invites
callers to expect detail that was never there. `rasterise` is where the
letterbox inverse lives, once.

`Letterbox` and `Window` become `pub(crate)` and `to_proto` generalises
to `to_grid`, because both dense outputs this crate reads are an even
fraction of the same letterboxed square and differ only in the divisor.

## Verified by looking, which is the only way this gets verified

`examples/scene.rs` writes the photograph dimmed outside each category. A
transposed axis or an off-by-one in the inverse produces perfectly
plausible weights over slightly the wrong pixels, and no unit test
catches that. On an indoor frame the person mask lands on the person,
including the outstretched arm, and sky reads ~5% against a bright
ceiling.

It doubles as the benchmark, because every timing quoted while this model
was chosen came off a laptop compiling other things and none of them
belong in a document.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-30 10:48:37 +02:00
dtourolleandClaude Opus 5 c75849040c Format the tree the way the gate asks for it
`cargo fmt --check` is a required step and had drifted across 45 files. Most of
it arrived this week: several operations were written in parallel worktrees and
merged by hand, and a hand-merge resolves conflicts without ever running the
formatter over the result.

No behaviour changes — this is `cargo fmt --all` and nothing else, kept as its
own commit so the next reader can skip it wholesale rather than search it for
one that matters.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-22 21:16:34 +02:00
dtourolle 0da8271836 Let the model say what a thing is and the watershed say where it ends
Local masking needs to know where an image's regions are. The watershed
spike (S15 arm A) found the boundaries but had no idea what any of them
enclosed; its coarse levels were geometric accidents. This adds the other
half and the thing that joins them.

`core/dr-segment` is where region reasoning now lives — the hierarchy moves
out of `dr-gpu`, which keeps only the pixel passes that are genuinely
shaders. The new crate is device-free and, without its default features,
model-free too: 20 of its tests need neither an adapter nor 11 MB of
weights.

Arm B runs YOLO26n-seg through `ort`. D13 framed inference as a choice
between `ort`'s C++ runtime and the pure-Rust dependency policy; that was a
false choice. `ort`'s `alternative-backend` feature unlinks the C entirely
and `ort-tract` supplies the API from tract, which is pure Rust. Measured
before committing to it: zero unsupported operators, 420 ms for 640x640,
and correct masks on bus.jpg. No NDK problem to solve, so D13's largest
tolerated exception is not needed.

Arm C is `prior.rs`, and it ships because the two arms fail in opposite
directions. Instance membership re-weights the merge saddles, so region
pairs the model believes share an object merge early and pairs straddling
its edge merge late. No boundary moves — only the order in which they
dissolve — which is how the result stays pixel-accurate at every level
while its coarse levels become named things.

Two things the spec assumed that turned out to be false, both recorded in
models/LICENCE.md: there is no usable ADE20K-trained YOLO, so the shipped
vocabulary is COCO's 80 subjects and *stuff* like sky and foliage must come
from arm A; and tract cannot parse a dynamic-shape export, so the graph's
input is fixed and tiling is the only route to more semantic resolution.

Weights are AGPL-3.0, which GPLv3 §13 permits and which makes the combined
work effectively AGPL. Deliberate, not accidental. They live in Git LFS,
and a build script fails with an instruction rather than embedding a
pointer file when the clone lacks them.
2026-08-22 08:39:16 +02:00