ctapipe.image.mars_cleaning_1st_pass(geom, image, picture_thresh=7, boundary_thresh=5, keep_isolated_pixels=False, min_number_picture_neighbors=0)[source]

Clean an image by selection pixels that pass a three-threshold tail-cuts procedure. All thresholds are defined with respect to the pedestal dispersion. All pixels that have a signal higher than the core (picture) threshold will be retained, along with all those above the boundary threshold that are neighbors of a core pixel AND all those above the boundary threshold that are neighbors of a neighbor of a core pixel.

geom: `ctapipe.instrument.CameraGeometry`

Camera geometry information

image: array

pixel values

picture_thresh: float

threshold above which all pixels are retained

boundary_thresh: float

threshold above which pixels are retained if they have a neighbor already above the picture_thresh; it is then reapplied iteratively to the neighbor of the neighbor

keep_isolated_pixels: bool

If True, pixels above the picture threshold will be included always, if not they are only included if a neighbor is in the picture or boundary

min_number_picture_neighbors: int

A picture pixel survives cleaning only if it has at least this number of picture neighbors. This has no effect in case keep_isolated_pixels is True

A boolean mask of clean pixels.