ruvnet/RuView · error · ValueError

Intrinsics file missing key

Error message

Intrinsics file {path} missing key {key!r}

What it means

load_intrinsics loads a precomputed camera-intrinsics JSON for the calibration flow. It accepts either a bare intrinsics dict or a full bundle containing a 'camera_intrinsics' object, then requires the keys camera_matrix, dist_coeffs, and image_size. The first missing key raises ValueError naming the file and the key.

Solutions

1. Regenerate the intrinsics file with the calibration flow so all three keys are written
2. If importing from elsewhere, map fields explicitly: K → camera_matrix (3x3), D → dist_coeffs, [w, h] → image_size
3. Pre-validate: jq 'has("camera_matrix") and has("dist_coeffs") and has("image_size")' intrinsics.json

Example fix

// before
// intrinsics.json
{"camera_matrix": [[800,0,320],[0,810,240],[0,0,1]]}

// after
// intrinsics.json
{"camera_matrix": [[800,0,320],[0,810,240],[0,0,1]],
 "dist_coeffs": [0,0,0,0,0],
 "image_size": [640,480]}

import json

REQUIRED = ("camera_matrix", "dist_coeffs", "image_size")

def intrinsics_valid(path: str) -> bool:
    with open(path, encoding="utf-8") as f:
        data = json.load(f)
    intr = data.get("camera_intrinsics", data) if isinstance(data, dict) else {}
    return isinstance(intr, dict) and all(k in intr for k in REQUIRED)

if not intrinsics_valid("intrinsics.json"):
    raise SystemExit(f"intrinsics file must contain {REQUIRED}")

try:
    intr = load_intrinsics(path)
except ValueError as e:
    raise SystemExit(f"regenerate the intrinsics file: {e}") from e

When it happens

Trigger: Passing an intrinsics file that contains only camera_matrix (no dist_coeffs/image_size), a bundle whose nested object uses different key names, or a geometry file where intrinsics were expected.

Common situations: Reusing intrinsics exported from another OpenCV pipeline that omits D or image size; hand-edited files; resolution changed after calibration so image_size is missing.

Related errors

• Calibration bundle missing key
• : each node needs 'id' and 'position_m' [x,y,z]
• : expected } or a top-level list
• Failed to load domain configuration
• Invalid axis token ; expected one of

AI-assisted analysis of ruvnet/RuView@4685618388 (2026-08-16). Data as JSON: /api/errors/9ea5a3ce03af2ddd. Report an issue: GitHub.

Appendix: source

Thrown at scripts/calibration_lib.py:153

    )
    return {
        "image_size": [int(image_size[0]), int(image_size[1])],
        "camera_matrix": camera_matrix.tolist(),
        "dist_coeffs": dist_coeffs.ravel().tolist(),
        "reprojection_error_px": float(rms),
        "source": "computed",
    }


def load_intrinsics(path: Path) -> dict:
    """Load a pre-computed intrinsics JSON ({camera_matrix, dist_coeffs, image_size})."""
    with open(path, "r", encoding="utf-8") as f:
        data = json.load(f)
    # Accept either a bare intrinsics dict or a full calibration bundle.
    intr = data.get("camera_intrinsics", data)
    for key in ("camera_matrix", "dist_coeffs", "image_size"):
        if key not in intr:
            raise ValueError(f"Intrinsics file {path} missing key {key!r}")
    intr = dict(intr)
    intr["source"] = "file"
    return intr


# ---------------------------------------------------------------------------
# Extrinsics (camera -> room rigid transform)
# ---------------------------------------------------------------------------

def reprojection_rmse(
    room_points: np.ndarray,
    image_points: np.ndarray,
    rvec: np.ndarray,
    tvec: np.ndarray,
    camera_matrix: np.ndarray,
    dist_coeffs: np.ndarray,
) -> float:
    proj, _ = cv2.projectPoints(room_points, rvec, tvec, camera_matrix, dist_coeffs)

View on GitHub (pinned to 4685618388)