Viewer Module

This module provides the Viewer class for capturing and decoding barcodes and QR codes from video streams. It uses OpenCV for video capture and pyzbar for decoding.

class VisionCommon.viewer.Viewer(camera_index: int = 0)

Bases: object

Viewer for capturing and scanning frames

__init__(camera_index: int = 0) → None

Initialize the viewer with a specified camera index.

Parameters:

camera_index (int) – Index of the camera. Defaults to 0.

capture_code(timeout_sec: int = None, timeout_frame: int = None, code_types: Iterable[ZBarSymbol] = None) → str | None

Captures codes based on timeout constraints.

Parameters:

  • timeout_sec (int, optional) – Maximum time in seconds.

  • timeout_frame (int, optional) – Maximum frame count.

  • code_types (Iterable[ZBarSymbol], optional) – Types of codes to decode.

Raises:

  • ValueError – For negative timeouts.

  • InvalidCombinationException – If no timeout is set.

Returns:

Decoded content, or None.

Return type:

Optional[str]

capture_frame() → ndarray | None

Captures a single frame from the camera.

Returns:

Captured frame, or None.

Return type:

Optional[ndarray]