ericek111/myscan
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Drop frames taken while the mouse lies still

Browse Source 
PageGraph.add skips a frame when neither the laser odometry nor a small
thumbnail shows it moved since the last kept frame, so resting on the page
no longer costs registration, solving and rendering time. LiveSession maps
captures to the kept frames for its sensor readings.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
erik
2026-10-12 08:22:27 +00:00
co-authored by Claude Opus 5.5
parent eeea9c3b30
commit 04c10e58c7
4 changed files with 45 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
README.md
+2 -1
View File
@@ -13,7 +13,8 @@ Linux driver tools for the Hama myScan (00052343) scanner mouse, a Dacuda design
prior; another device can pass its own object with `predict()`), `register` (ECC, phase correlation, SIFT
matching, overlap check), `canvas` (weighted canvases, page composition, parallel rendering), `posegraph`
(robust pose-graph optimisation), `loops` (loop-closure candidates), and the two stitchers built from them:
`pagegraph` (`PageGraph`: assembles the page from all frames at once with loop closures between passes;
`pagegraph` (`PageGraph`: assembles the page from all frames at once with loop closures between passes,
dropping frames taken while the mouse lies still;
used by `scan.py` and `stitch.py`) and `incremental` (`Stitcher`: frame by frame, `stitch.py --live`)
- `tools/scan.py` — scan with the button: `python tools/scan.py` (press to start, press again to stop).
`--view [PORT]` serves a live view at `http://<host>:8000/`: the camera, the page as it is stitched
myscan/live.py
+13 -8
View File
@@ -108,6 +108,7 @@ class LiveSession:
self.preview = LivePreview(graph)
self.raw = self.rec = None # latest captured frame and its sensor record (on_capture)
self.e6, self.times = 0, []
self.frame_of = [] # graph frame showing each processed capture (still ones are dropped)
self.dist, self.dist_done = 0.0, 0
viewer.set_status(sensors=None)
self._solving = True
@@ -124,7 +125,10 @@ class LiveSession:
self.raw, self.rec, self.e6 = raw, rec, e6
def on_frame(self, corrected):
self.preview.add(corrected)
"""Called with what PageGraph.add returned for each captured frame, in order."""
self.frame_of.append(self.g.n - 1)
if corrected is not None:
self.preview.add(corrected)
def sensors(self, window=0.3):
"""Live readings for the viewer, or None before the first registered frame:
@@ -137,10 +141,11 @@ class LiveSession:
only had the lasers, which happens when moving too fast or lifted);
lasers: the two laser sensors' surface quality (record bytes 14, 15);
exposure (ms), level: paper brightness (0-255), fps."""
g, times, rec = self.g, self.times, self.rec
i = len(g.odo) # newest frame with an odometry edge
if i < 1 or i >= len(times) or rec is None:
g, times, rec, frame_of = self.g, self.times, self.rec, self.frame_of
k = len(frame_of) - 1 # newest processed capture
if k < 1 or rec is None:
return None
i = frame_of[k] # and the graph frame that shows it
c = np.array([g.w / 2, g.h / 2, 1.0])
def centre(k):
@@ -152,10 +157,10 @@ class LiveSession:
# The frame's x axis, (cos θ, sin θ) on the canvas, is (-sin θ, -cos θ) on the page:
# it points up at θ = 0 and turns by -θ.
heading = -np.degrees(np.arctan2(M[1, 0], M[0, 0]))
j = bisect.bisect_left(times, times[i] - window, 0, i)
j = bisect.bisect_left(times, times[k] - window, 0, k)
p = centre(i)
dt = times[i] - times[j]
vel = (p - centre(j)) * self.mm / dt if j < i and dt > 0 else np.zeros(2)
dt = times[k] - times[j]
vel = (p - centre(frame_of[j])) * self.mm / dt if j < k and dt > 0 else np.zeros(2)
for _, _, T, _ in g.odo[self.dist_done:i]:
self.dist += float(np.hypot(*(T @ c - c)[:2])) * self.mm
self.dist_done = i
@@ -168,7 +173,7 @@ class LiveSession:
"velocity": [float(v) for v in vel], "speed": float(np.hypot(*vel)),
"distance": self.dist, "offset": [float(v) for v in (p - centre(0)) * self.mm],
"area": self.preview.covered * (self.mm / self.preview.s) ** 2 / 100,
"tracking": sum(e[3] == SIGMA_ECC for e in recent) / len(recent),
"tracking": sum(e[3] == SIGMA_ECC for e in recent) / len(recent) if recent else 1.0,
"lasers": [int(rec.b14), int(rec.b15)],
"exposure": self.e6 / E6_PER_MS, "level": bright_level(raw) if raw is not None else 0.0,
"fps": float(fps),
myscan/scanner.py
+2 -1
View File
@@ -112,7 +112,8 @@ def scan_page(x, a, frames_dir=None, corrector=None, gains=None, viewer=None, mm
if viewer:
viewer.set_status(t=t, frames=n + 1, backlog=work.qsize())
if t - last >= 1:
print(f"\r {t:5.1f}s {n + 1} frames ({g.n} registered) E6={s.e6}", end="", flush=True)
print(f"\r {t:5.1f}s {n + 1} frames ({g.n} stitched, {g.stats['still']} still) E6={s.e6}",
end="", flush=True)
last = t
print()
if viewer:
myscan/stitching/pagegraph.py
+28 -3
View File
@@ -17,6 +17,9 @@ wrong copy. Here every frame keeps its own pose and the poses are solved togethe
pose; the rest (off the page, lifted, corrupt) only had the odometry and are left out,
as are frames that disagree with the mosaic of all the others.
Frames that show nothing new (the mouse lying still) are dropped on arrival: they cost
registration, solving and rendering time and add nothing to the page.
A pose M (3x3) maps frame pixels to canvas pixels; an edge (i, j, T) says M_j ~ M_i @ T.
"""
import os
@@ -37,6 +40,10 @@ SIGMA_ECC = 1.0 # px, edge registered by ECC
SIGMA_ODO = 6.0 # px, odometry edge from the motion prior only
SIGMA_LOOP = 1.5 # px, loop closure
PRUNE = 5.0 # drop loop edges whose residual exceeds this many sigmas
STILL_PX = 1.0 # odometry motion (px at the frame corners) below which a frame may be still
STILL_DIFF = 0.01 # and thumbnail difference below which it is (sensor noise is ~0.002,
# slow motion 0.01-0.03; relative to the mean, so exposure changes don't count)
THUMB = (80, 37) # thumbnail size for that test
class PageGraph:
@@ -56,10 +63,12 @@ class PageGraph:
self._hpf = {}
self.odo, self.bridges, self.loops = [], [], [] # edges: (i, j, T, sigma)
self.prev_v = None
self._thumb = None # of the last frame added
self._feat, self._tried = {}, set() # kept across solves
self._pool = None
self.solution = None # (poses (n, 3), indices of frames to draw)
self.stats = {"frames": 0, "odo_ecc": 0, "odo_laser": 0, "bridges": 0, "loop_tries": 0, "pruned": 0}
self.stats = {"frames": 0, "odo_ecc": 0, "odo_laser": 0, "bridges": 0, "loop_tries": 0, "pruned": 0,
"still": 0}
@property
def n(self):
@@ -76,13 +85,29 @@ class PageGraph:
self._feat[i] = register.detect(self._hp(i))
return self._feat[i]
def _still(self, thumb, v):
"""Whether a frame with this thumbnail and sensor values shows the same as the last
frame added: neither the odometry (without image shift) nor the image moved."""
T, _ = self.odometry.predict(self.prev_v, v, self.center)
q = np.array([[0, self.w, 0, self.w], [0, 0, self.h, self.h], [1, 1, 1, 1]])
if np.abs(T @ q - q).max() >= STILL_PX:
return False
return cv2.norm(thumb, self._thumb, cv2.NORM_L1) / thumb.size < STILL_DIFF
def add(self, frame, v):
"""frame: HxW or HxWx3 uint8 raw frame; v: its sensor values for the odometry (the
myScan record's six raw values). Returns the corrected float frame.
myScan record's six raw values). Returns the corrected float frame, or None if the
frame was dropped as still (see _still).
Safe to call while solve() runs on another thread."""
v = np.asarray(v)
thumb = cv2.resize(frame, THUMB, interpolation=cv2.INTER_AREA).astype(np.float32)
thumb = gray(thumb) / max(float(thumb.mean()), 1.0)
if self.n and self._still(thumb, v):
self.stats["still"] += 1
return None
self._thumb = thumb
f = self.correct(frame)
hs = cv2.resize(highpass_fast(gray(f)), self.half, interpolation=cv2.INTER_AREA)
v = np.asarray(v)
i = self.n
self.frames.append(frame)
self.hs.append(hs)