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exposure

exposure #

The per-frame camera-exposure JSON scalar.

Exposure #

Bases: JSONScalar

A frame's photometric context: exposure at capture and ambient light estimate.

Rides beside a Pose on a captured frame so an appearance-aware pipeline (e.g. gaussian splatting) can normalize brightness and white balance across frames without re-deriving them from pixels. The light estimate is absent when the capturing session did not estimate it.

Attributes:

Name Type Description
duration_seconds float

Sensor exposure time.
offset_ev float

Exposure bias relative to the metered value.
ambient_intensity_lumens float | None

Estimated scene luminance (~1000 is a neutrally lit scene), if estimated.
color_temperature_kelvin float | None

Estimated ambient colour temperature (~6500 is neutral), if estimated.
Source code in capturegraph-lib/capturegraph/types/scalars/imaging/exposure.py 
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class Exposure(JSONScalar, name="edu.cornell.exposure"):
    """A frame's photometric context: exposure at capture and ambient light estimate.

    Rides beside a ``Pose`` on a captured frame so an appearance-aware pipeline
    (e.g. gaussian splatting) can normalize brightness and white balance across
    frames without re-deriving them from pixels. The light estimate is absent
    when the capturing session did not estimate it.

    Attributes:
        duration_seconds: Sensor exposure time.
        offset_ev: Exposure bias relative to the metered value.
        ambient_intensity_lumens: Estimated scene luminance (~1000 is a
            neutrally lit scene), if estimated.
        color_temperature_kelvin: Estimated ambient colour temperature
            (~6500 is neutral), if estimated.
    """

    duration_seconds: float
    offset_ev: float
    ambient_intensity_lumens: float | None = None
    color_temperature_kelvin: float | None = None