dcnum.read.detect_flicker

Functions

detect_flickering(image_data[, roi_height, ...])

Determine whether an image series experiences flickering

Module Contents

dcnum.read.detect_flicker.detect_flickering(image_data: numpy.ndarray | dcnum.read.hdf5_data.HDF5Data, roi_height: int = 10, brightness_threshold: float = 2.5, count_threshold: int = 5, max_frames: int = 1000)[source]

Determine whether an image series experiences flickering

Flickering is an unwelcome phenomenon due to a faulty data acquisition device. For instance, if there is random voltage noise in the electronics managing the LED power, then the brightness of the LED will vary randomly when the noise signal overlaps with the flash triggering signal.

If flickering is detected, you should use the “sparsemed” background computation with offset_correction set to True.

Parameters:

  • image_data – sliceable object (e.g. numpy array or HDF5Data) containing image data.

  • roi_height (int) – height of the ROI in pixels for which to search for flickering; the entire width of the image is used

  • brightness_threshold (float) – brightness difference between individual ROIs median and median of all ROI medians leading to a positive flickering event

  • count_threshold (int) – minimum number of flickering events that would lead to a positive flickering decision

  • max_frames (int) – maximum number of frames to include in the flickering analysis