The DNG a merge writes has no embedded preview, and an embedded preview
is all the grid's thumbnail path reads, so a composite stood in the grid
as a blank cell until it was opened. Reading an 800 MB file back to make
one would cost what the merge already has in hand.
The bands are box-reduced as they are written, after the border fill,
into a copy 4096 pixels long. That copy is written as a linear DNG in
memory with the composite's own profile, header and crop, and opened
through open_session, the function develop opens every file with: the
same decode, the default graph and view transform, the as-shot white
balance and the conversion to the display's space. The grid and large
thumbnails are rendered from that session, staged beside the payload
before the rename releases it to a drain, and put in the store under the
file id once the upload has learned it. Until then the grid draws them
from memory, so the cell is not blank while the file is uploading.
A test develops a synthetic composite both ways, the whole file as
develop opens it and the merge's reduced copy, and holds the thumbnail's
mean, 95th and 99.5th luma percentiles to within 3-4 levels of develop's
render; the naive balanced-and-gamma picture the merge's preview draws
misses by 13.
A finished merge drained the outbox and started a rescan beside it. The
scan raced the upload: on a folder library the 800 MB copy was still
running when the folder was listed, on Nextcloud the upload takes
minutes, and either way the listing lacked the composite, recorded the
folder's validator, and nothing looked again until the next sync pass.
The job now reports what the catalog needs (the name, the size of the
picture it opens on, the capture time it wrote into the DNG) and the
library writes the row at once, in one transaction, keyed where the scan
will list the file; a composite with no time of its own takes its
sources' earliest. The grid reloads and shows it beside its sources.
The upload then gives the row what only the server knows: after sending
a file the catalog already has a row for, it lists the folder once, takes
the file id the server assigned, and records it (and, once the merge
makes them, the thumbnails waiting beside the payload) under that id.
Every drain now rescans when something landed in the library, after the
upload rather than beside it. A second merge of the same frames is no
longer named over the first: the name is checked against the catalog's
names in that folder, which is all that knows it once the outbox is empty.
The merge writes its outbox record before the DNG, which takes minutes,
and a drain that ran in the meantime took whatever lay at the record's
name: a sync pass that fired mid-merge uploaded the first part of the
composite and cleared the record. The file is now written as x.dng.part
and renamed into place once the last strip is in; the drain skips a
record whose payload does not exist yet.
A frame that did not fit ended the job with its name, and the only way
on was Back, a smaller selection and every frame read, demosaiced and
searched for keypoints again. Each row on the page now has a box. An
unticked frame is left out and the rest are solved again from what the
first pass measured.
dr_pano::align is split for it: match_pairs does the matching and the
pairwise RANSAC once over every frame (about 5 s for twelve), and solve
takes a subset of the frames and uses only the links among them (about
0.1 s). Solving a subset by re-aligning it also moved every RANSAC seed,
which are keyed on frame position, and on the fixture set that was
enough to lose a marginal link and strand a neighbour of the frame left
out.
A frame that cannot be placed no longer stops the job either. Its row
names it and Merge stays off until it is unticked; the headless example
leaves such frames out the same way, and takes --leave-out N to try it.
A clipped photosite reaches the merge as (1, 1, 1), which the as-shot
balance turns magenta. The preview balanced it with no highlight rule at
all, so every blown cloud was pink on the alignment page. The DNG had the
quieter form of the same fault: a frame's gain below one moved a blown
sample off the white level, and a feather mixed it into a neighbour's
real sky, so the develop's own desaturation no longer recognised it.
The merge shader and the preview now write a blown sample, before the
gain, as the camera value the composite's balance calls grey — the
develop pipeline's neutral, fading in from CLIP_ONSET.
Thirty-nine spawn sites in dr-ui, and one in the Android entry point,
called std::thread::spawn or a Builder of their own, and most of the
threads they started were <unnamed> in a panic message or a profiler.
Each now calls executors::spawn with its executor and a role, so the thread is
named <executor>:<role> — net:sync, decode:thumbs, io:catalog-open —
and knows which executor it is on. The three that already set a name
(automation, import, prefetch) keep their name as the role.
Behaviour is unchanged: each job still gets a thread of its own when it
starts, and spawn panics where std::thread::spawn did.
The module's documentation now says how a job is assigned: by what it
spends its time on, so a sweep that fetches bytes and then decodes them
is Decode, and a sidecar write that touches the catalog is Network.
Left as they were: the segmentation and refine workers in masks_ui.rs,
which another change is reworking, and test-only threads.
With the trait in place the claim still meant nothing while every caller
named dr_decode's free functions: a second decoder would have had to be
threaded through the scan, the thumbnail ladder, import, the viewer,
export, merge and repairs at the moment it arrived.
Each of those now takes a &dyn Decoder and reads headers, previews,
orientation and sensor data through it, including the header budget a
remote fetch asks for (header_bytes) and where it finds the embedded
preview (locate_preview). Only the places that start a job name
dr_decode::default(): the thumbnail, sweep and thumbnail-sweep threads,
the viewer's open handlers, and the request structs a job is handed
(BatchRequest, MergeRequest, the import Request, the repairs Toolkit),
so a caller can be given another decoder by changing what it is handed.
The default is rawler through the same free functions as before, so
nothing a user sees changes. The trait gains Debug as a supertrait so
request structs that derive Debug can carry one.
wgpu reports a device out of memory by panicking, and a twelve-frame
merge on a GPU another process is using is where that happens. The panic
unwound the worker, the sender went with it, and the page sat on "Stop"
with every control disabled and nothing to say why — the crash record on
disk was the only sign. Catch the panic and send it as a failure, and
treat a closed channel with no final event as a dead worker too.
A Border choice beside the projection — crop to the picture, or fill it
— that redraws the preview filled so the invented pixels are seen before
they are confirmed (FR-MRG-1), greyed with the reason when the model is
not there. The job fills at half the composite's resolution in a
display-ish space (white balance, matrix, gamma; invertible) and samples
the result back into the linear DNG wherever no frame reached; the
sidecar's merge line says border filled and with which knobs.
Experimental because the fill is right in thin borders and wrong in deep
corners, where the model's Places2 prior puts clouds in sky and water
under grass; so its six knobs — working scale, edge erosion, coarse pass,
band width, mirror depth, seam feather — are sliders under the choice,
each committing a redraw, until the defaults are right.
Picking a chip stored the choice for the merge and changed nothing on
screen — the chip did not even highlight, since the selected property
was never written back. Now the pick is reflected, and the job, waiting
for its decision, takes a Preview request, draws the alignment on the
chosen surface at proxy cost and reports again; the drain puts the new
picture and its size up. Auto is the surface the field of view suggests.
Also:
The largest rectangle inside the frames' coverage is found a row at a
time — a histogram of consecutive covered rows and a stack pass per row —
so the composite is never held to be measured (FR-MRG-11). It is written
as DefaultCropOrigin/DefaultCropSize (FR-MRG-4): the file opens on the
picture, the border is still in it, and resetting the crop shows it.
rawler reports the crop as the picture, which the test checks.
FR-MRG-4 records the question raised the same day — fill the border
rather than crop it — as open: a non-generative fill through the heal,
or a generative inpainter with its licence and weights. Neither decided.
A sweep whose frames overlap by more than half reads as one photograph,
and the page's job is to show frames. Each footprint is walked along its
border and drawn in amber where it lands, so twelve frames look like
twelve and a misplaced one is visible as such. The preview may take most
of the page's height rather than 320 px.
derived_from and merge are top-level sidecar fields (FR-MRG-6): one line
per source in order, and how the composite was made. A build that
predates them keeps the lines as unknown and writes them back. The job
writes the sidecar beside the composite and stages it with its own
record when the composite goes through the outbox.
DARKROOM_START_MERGE=a.CR2,b.CR2 lands on the merge page at startup with
the job running on local files, on the model of DARKROOM_START_IDENTITY,
for looking at the page where synthetic clicks do not reach it. The fetch
and the start are shared with the grid's button.
panorama.md §11 records what exists, the fixture's figures, and the six
things still open, auto-crop first.
dr_ui::merge is the orchestration with no interface in it: decode each
frame to sensor data and build its graph as a session would (orientation,
lens profile); render each through the camera-space tap at proxy size and
detect keypoints there, so the alignment is measured in the undistorted
frame the tiles are rendered in; align; solve one gain per frame from the
proxies' overlaps; draw the aligned set in colour for the page; then wait.
Nothing is written until a Decision arrives (FR-MRG-1). The merge writes
a linear DNG through the outbox with a destination record, so the drain
puts it beside its sources on a folder library and a server alike, and
the library rescans (FR-MRG-3).
merge.slint is the page, on the import page's model: the alignment
table with a failed frame named on its row and the button held off
(FR-MRG-5), the preview, the projection choice, Stop and Back. A
"Merge to panorama" button joins the grid's selection bar at two frames.
Headless, the example produces the fixture's 22 993 x 5 980 DNG in 45 s
on the reference desktop, exposures balanced across the stop of drift.