porespy.filters.local_thickness#

porespy.filters.local_thickness(im: numpy.typing.NDArray, dt: numpy.typing.NDArray = None, method: Literal['bf', 'conv', 'dt', 'legacy'] = 'bf', smooth: bool = True, mask: numpy.typing.NDArray = None, approx: bool = False, sizes: int = _DEFAULT_SIZES, return_indices: bool = False)#

Insert a maximally inscribed sphere at every pixel labelled by sphere radius

This is a wrapper method for computing local thickness via a variety of different methods.

Parameters:

  • im (ndarray) – Boolean image of the porous material

  • dt (ndarray, optional) – The distance transform of the image

  • method (str) –

    Which method to use to compute the local thickness. Options are:

    Method

    Description

    ’dt’

    Uses distance transforms to perform erosion and dilation for each radius in the image

    ’bf’

    Uses brute-force to inserts spheres at each voxel

    ’conv’

    Uses FFT-based convolution to perform erosion and dilation for each radius in the image

    ’legacy’

    Reproduces the former fractional-radius distance-transform method

  • sizes (array_like or scalar) – The positive integer radii to evaluate. If an integer N is provided, up to N integer radii are selected at evenly spaced intervals between 1 and floor(dt.max()). If omitted or None, every integer radius in that range is used. For method='legacy', omitting this argument uses the former default of 25 logarithmically-spaced fractional radii; an explicit None uses all unique distance-transform values.

  • smooth (bool, optional) – Indicates if protrusions should be removed from the faces of the spheres or not. Default is True.

  • mask (ndarray, optional) – This is only used if the method is bf or imj. A boolean mask indicating which sites to insert spheres at. If not provided then all True values in im are used.

  • approx (bool, optional) – Retained for compatibility with imj and has no effect.

  • return_indices (bool, optional) – If True, return (sizes, indices) instead of a float image, where sizes[indices] reconstructs the usual result. The index image uses the smallest suitable unsigned integer dtype. Default is False.

Returns:

lt – The local thickness of the image with each voxel labelled according to the radius of the largest sphere which overlaps it, or (sizes, indices) when return_indices is True.

Return type:

ndarray or tuple[ndarray, ndarray]

Examples

Click here to view online example.

On this page