The merge weighted every overlap pixel by its distance from each frame's
edge, a 200 px linear cross-fade. Anything the frames disagreed on —
parallax in the near foreground, grass in the wind, a walker — came out
twice at half strength: a soft double edge at 1:1.
dr_pano::seam picks, per output texel at proxy resolution, which frame a
pixel comes from. Where a new frame overlaps the composite the cost is the
gain-corrected difference plus local detail plus nearness to either
frame's edge, taken as the worst over a small window, and the cut is a
dynamic-programming path across the overlap. merge.wgsl weights each frame
by its tent-filtered share of that map, a 64 px blend that follows the
seam, with the edge feather kept as the fallback. The page's preview uses
the same map, and examples/merge.rs takes --feather-only for comparison.
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 fill that went wrong took a seven-minute merge to look at again. Now
DR_FILL_DUMP=dir makes the merge write what the filler was given, and
the fill example runs fill_border on that, or a crop of it, on the engine
and writes coarse, each band and the feathered result as PPMs — seconds
per attempt on TensorRT. Both examples take DARKROOM_ORT_DIR as the app
does, and --wait-engines lets a compiling rung finish before timing.
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.
dtourolle