fact_image_cleaning#
- ctapipe.image.fact_image_cleaning(geom, image, arrival_times, picture_threshold=4, boundary_threshold=2, min_number_neighbors=2, time_limit=5)[source]#
Clean an image by selection pixels that pass the fact cleaning procedure.
Cleaning contains the following steps: 1: Find pixels containing more photons than a threshold t1 2: Remove pixels with less than N neighbors 3: Add neighbors of the remaining pixels that are above a lower threshold t2 4: Remove pixels with less than N neighbors arriving within a given timeframe 5: Remove pixels with less than N neighbors 6: Remove pixels with less than N neighbors arriving within a given timeframe
- Parameters:
- geomctapipe.instrument.CameraGeometry
Camera geometry information
- imagenp.ndarray
pixel charges
- arrival_timesnp.ndarray
pixel timing information
- picture_thresholdfloat | np.ndarray
threshold above which all pixels are retained
- boundary_thresholdfloat | np.ndarray
threshold above which pixels are retained if they have a neighbor already above the picture_thresh
- min_number_neighborsint
Threshold to determine if a pixel survives cleaning steps. These steps include checks of neighbor arrival time and value
- time_limitint | float
arrival time limit for neighboring pixels
- Returns:
- A boolean mask of clean pixels.
References