Files
calibration/imu_lidar/motion_pairs_io.py
T

155 lines
5.0 KiB
Python

"""Serialize / deserialize motion pairs for fast visualization."""
from __future__ import annotations
import json
from pathlib import Path
from typing import Any
import numpy as np
from .contracts import MotionPair
SCHEMA_VERSION = 2
# Keep visualization fields plus the compact 3x3 rotation metadata needed to
# rerun Phase-A without repeating LiDAR registration. Full 9x9 Phase-C matrices
# remain excluded from this cache.
_METADATA_KEEP = frozenset(
{
"backend",
"rotation_deg_A",
"rotation_deg_B",
"translation_m_B",
"weight",
"duration_s",
"mean_gyro_norm",
"preint_sigma_rad",
"cov",
"J_bg",
"phase_a_metadata_rehydrated",
"rehydrated_R_A_error_deg",
"t_i_imu_s",
"t_j_imu_s",
"gyro_bias0_rad_s",
"accel_bias0_m_s2",
"time_offset_s",
"keyframe_span",
"is_consecutive",
"modeling",
}
)
def _to_list(value: Any) -> Any:
if isinstance(value, np.ndarray):
return value.tolist()
if isinstance(value, (np.floating, np.integer, np.bool_)):
return value.item()
return value
def pair_to_dict(pair: MotionPair) -> dict[str, Any]:
meta = {
str(k): _to_list(v)
for k, v in (pair.metadata or {}).items()
if str(k) in _METADATA_KEEP
}
return {
"session_id": pair.session_id,
"i": int(pair.i),
"j": int(pair.j),
"t_i_s": float(pair.t_i_s),
"t_j_s": float(pair.t_j_s),
"R_A": np.asarray(pair.R_A, dtype=float).reshape(3, 3).tolist(),
"R_B": np.asarray(pair.R_B, dtype=float).reshape(3, 3).tolist(),
"t_A_m": None if pair.t_A_m is None else np.asarray(pair.t_A_m, dtype=float).reshape(3).tolist(),
"t_B_m": None if pair.t_B_m is None else np.asarray(pair.t_B_m, dtype=float).reshape(3).tolist(),
"fitness": float(pair.fitness),
"metadata": meta,
}
def pair_from_dict(payload: dict[str, Any]) -> MotionPair:
t_a = payload.get("t_A_m")
t_b = payload.get("t_B_m")
return MotionPair(
session_id=str(payload.get("session_id", "")),
i=int(payload["i"]),
j=int(payload["j"]),
t_i_s=float(payload["t_i_s"]),
t_j_s=float(payload["t_j_s"]),
R_A=np.asarray(payload["R_A"], dtype=float).reshape(3, 3),
R_B=np.asarray(payload["R_B"], dtype=float).reshape(3, 3),
t_A_m=None if t_a is None else np.asarray(t_a, dtype=float).reshape(3),
t_B_m=None if t_b is None else np.asarray(t_b, dtype=float).reshape(3),
fitness=float(payload.get("fitness", 0.0)),
metadata=dict(payload.get("metadata") or {}),
)
def build_motion_pairs_payload(
*,
prepared_sessions: list[dict[str, Any]],
) -> dict[str, Any]:
"""Build a JSON-serializable cache from pipeline ``prepared`` session dicts."""
sessions_out: list[dict[str, Any]] = []
for prep in prepared_sessions:
pairs = prep.get("pairs") or ()
sessions_out.append(
{
"session_id": prep.get("session_id"),
"delta_t_s": float(prep.get("time_offset_s", 0.0)),
"gyro_bias_rad_s": np.asarray(prep.get("gyro_bias_rad_s", np.zeros(3)), dtype=float)
.reshape(3)
.tolist(),
"pair_count": len(pairs),
"pairs": [pair_to_dict(pair) for pair in pairs],
}
)
return {
"schema_version": SCHEMA_VERSION,
"sessions": sessions_out,
"note": "Cached motion pairs for visualization; A=IMU preintegration, B=LiDAR registration",
}
def save_motion_pairs(path: Path | str, payload: dict[str, Any]) -> Path:
destination = Path(path)
destination.parent.mkdir(parents=True, exist_ok=True)
destination.write_text(json.dumps(payload, indent=2), encoding="utf-8")
return destination
def load_motion_pairs(path: Path | str) -> dict[str, Any]:
payload = json.loads(Path(path).read_text(encoding="utf-8"))
version = int(payload.get("schema_version", 0))
if version not in {1, SCHEMA_VERSION}:
raise ValueError(
f"unsupported motion_pairs schema_version={version}; "
f"expected 1 or {SCHEMA_VERSION}"
)
return payload
def pairs_for_session(payload: dict[str, Any], session_id: str | None = None) -> list[MotionPair]:
sessions = payload.get("sessions") or []
if not sessions:
return []
if session_id is None:
chosen = sessions[0]
else:
chosen = next((s for s in sessions if s.get("session_id") == session_id), None)
if chosen is None:
raise KeyError(f"session_id {session_id!r} not found in motion_pairs cache")
return [pair_from_dict(item) for item in chosen.get("pairs") or []]
def resolve_motion_pairs_path(summary_path: Path | str) -> Path | None:
"""Return ``motion_pairs.json`` next to a summary if it exists."""
summary = Path(summary_path)
candidate = summary.parent / "motion_pairs.json"
return candidate if candidate.is_file() else None