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WebcamCapture API#

WebcamCapture puts a live camera preview in the notebook with a capture button and an auto-capture toggle. Each snapshot lands in image_base64, and get_pil() or get_bytes() turn it into something a model can eat. Set interval_ms and flip capturing to pull frames on a cadence — enough to run inference on a rough video stream. facing_mode picks the front or rear camera; error reports refused access.

See also: Paint for drawing on a canvas instead of photographing one, HoverZoom for inspecting a captured frame up close, and FramePlayer for replaying a run of captures as a loop.

Bases: AnyWidget

Webcam capture widget with manual and interval snapshots.

The widget shows a live webcam preview plus a capture button and an auto-capture toggle. When capturing is enabled, the browser updates image_base64 on the cadence specified by interval_ms.

Examples:

import marimo as mo
from wigglystuff import WebcamCapture

cam = mo.ui.anywidget(WebcamCapture(interval_ms=1000))
cam

Create a WebcamCapture widget.

Parameters:

Name Type Description Default
interval_ms int

Capture interval in milliseconds when auto-capture is on.

 1000
facing_mode str

Camera facing mode ("user" or "environment").

 'user'
Source code in wigglystuff/webcam_capture.py 
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def __init__(self, interval_ms: int = 1000, facing_mode: str = "user") -> None:
    """Create a WebcamCapture widget.

    Args:
        interval_ms: Capture interval in milliseconds when auto-capture is on.
        facing_mode: Camera facing mode ("user" or "environment").
    """
    super().__init__(interval_ms=interval_ms, facing_mode=facing_mode)

get_bytes #

get_bytes() -> bytes

Return the captured frame as raw bytes.

Source code in wigglystuff/webcam_capture.py 
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def get_bytes(self) -> bytes:
    """Return the captured frame as raw bytes."""
    if not self.image_base64:
        return b""
    payload = self.image_base64
    if "base64," in payload:
        payload = payload.split("base64,", 1)[1]
    return base64.b64decode(payload)

get_pil #

get_pil()

Return the captured frame as a PIL Image.

Source code in wigglystuff/webcam_capture.py 
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def get_pil(self):
    """Return the captured frame as a PIL Image."""
    if not self.image_base64:
        return None
    try:
        from PIL import Image
    except ImportError as exc:  # pragma: no cover - optional dependency
        raise ImportError("PIL is required to use get_pil().") from exc

    return Image.open(BytesIO(self.get_bytes()))

Synced traitlets#

Traitlet Type Notes
image_base64 str PNG data URL for the latest frame.
capturing bool Enable auto-capture mode.
interval_ms int Auto-capture interval in milliseconds.
facing_mode str Camera facing mode ("user" or "environment").
ready bool True when the preview stream is ready.
error str Error message when webcam access fails.