Module i2pp.core.interpolators.interpolator_center

Interpolates pixel values from image-data to mesh-data.

Classes

class InterpolatorCenter
Expand source code 
class InterpolatorCenter(Interpolator):
    """Subclass of Interpolator for mapping 3D image data to finite element
    mesh centers.

    This class extends the Interpolator and specializes in assigning pixel
    values from 3D image data to finite element mesh elements by interpolating
    at their centers. This approach is used when `interpolation_method` is set
    to "elementcenter".
    """

    def compute_element_centers(self, dis: Discretization) -> Discretization:
        """Computes the centroid of each element in a finite element mesh.

        This method calculates the centroid of each element in a given
        Discretization by averaging the coordinates of its associated nodes.
        The centroid is then stored as an attribute (`center_coords`) for each
        element.

        Arguments:
            dis (Discretization): A finite element mesh containing elements
                and their associated nodes.

        Returns:
            Discretization: The input Discretization object with updated
                centroid coordinates for each element.
        """

        for i, ele in tqdm(
            enumerate(dis.elements),
            total=len(dis.elements),
            desc="Calculate element center",
        ):

            node_position = get_node_position_of_element(
                ele.node_ids, dis.nodes.ids
            )
            element_coords = dis.nodes.coords[node_position]
            centroid = np.mean(element_coords, axis=0)

            ele.center_coords = np.array(centroid)

        return dis

    def compute_element_data(
        self, dis: Discretization, image_data: ImageData
    ) -> list[Element]:
        """Interpolates pixel values to finite element mesh elements using
        element centers.

        This method assigns interpolated pixel values to each element in the
        Discretization based on its centroid. It first computes the centroid
        for each element, maps those coordinates to the image grid, and then
        retrieves the corresponding pixel values through interpolation.

        Arguments:
            dis (Discretization): A finite element mesh containing elements
                and their associated nodes.
            image_data (ImageData): A structured representation of 3D image
                data, including pixel intensities, grid coordinates, and
                orientation.

        Returns:
            list[Element]: A list of elements with interpolated pixel values
                assigned.
        """

        dis = self.compute_element_centers(dis)

        element_center_world_coords = np.array(
            [ele.center_coords for ele in dis.elements]
        )
        element_center_grid_coords = self.world_to_grid_coords(
            element_center_world_coords,
            image_data.orientation,
            image_data.position,
        )

        ele_center_values = self.interpolate_image_values_to_points(
            element_center_grid_coords, image_data
        )

        for i, ele in tqdm(
            enumerate(dis.elements),
            total=len(dis.elements),
            desc="Processing Elements",
        ):
            ele.data = ele_center_values[i]

            if np.all(np.isnan(ele.data)):
                self.nan_elements += 1

        self._log_interpolation_warnings()

        return dis.elements

Subclass of Interpolator for mapping 3D image data to finite element mesh centers.

This class extends the Interpolator and specializes in assigning pixel values from 3D image data to finite element mesh elements by interpolating at their centers. This approach is used when interpolation_method is set to "elementcenter".

Initialize the Interpolator.

Ancestors

Methods

def compute_element_centers(self,
dis: Discretization) ‑> Discretization
Expand source code 
def compute_element_centers(self, dis: Discretization) -> Discretization:
    """Computes the centroid of each element in a finite element mesh.

    This method calculates the centroid of each element in a given
    Discretization by averaging the coordinates of its associated nodes.
    The centroid is then stored as an attribute (`center_coords`) for each
    element.

    Arguments:
        dis (Discretization): A finite element mesh containing elements
            and their associated nodes.

    Returns:
        Discretization: The input Discretization object with updated
            centroid coordinates for each element.
    """

    for i, ele in tqdm(
        enumerate(dis.elements),
        total=len(dis.elements),
        desc="Calculate element center",
    ):

        node_position = get_node_position_of_element(
            ele.node_ids, dis.nodes.ids
        )
        element_coords = dis.nodes.coords[node_position]
        centroid = np.mean(element_coords, axis=0)

        ele.center_coords = np.array(centroid)

    return dis

Computes the centroid of each element in a finite element mesh.

This method calculates the centroid of each element in a given Discretization by averaging the coordinates of its associated nodes. The centroid is then stored as an attribute (center_coords) for each element.

Arguments

dis (Discretization): A finite element mesh containing elements and their associated nodes.

Returns

Discretization
The input Discretization object with updated centroid coordinates for each element.
def compute_element_data(self,
dis: Discretization,
image_data: ImageData) ‑> list[Element]
Expand source code 
def compute_element_data(
    self, dis: Discretization, image_data: ImageData
) -> list[Element]:
    """Interpolates pixel values to finite element mesh elements using
    element centers.

    This method assigns interpolated pixel values to each element in the
    Discretization based on its centroid. It first computes the centroid
    for each element, maps those coordinates to the image grid, and then
    retrieves the corresponding pixel values through interpolation.

    Arguments:
        dis (Discretization): A finite element mesh containing elements
            and their associated nodes.
        image_data (ImageData): A structured representation of 3D image
            data, including pixel intensities, grid coordinates, and
            orientation.

    Returns:
        list[Element]: A list of elements with interpolated pixel values
            assigned.
    """

    dis = self.compute_element_centers(dis)

    element_center_world_coords = np.array(
        [ele.center_coords for ele in dis.elements]
    )
    element_center_grid_coords = self.world_to_grid_coords(
        element_center_world_coords,
        image_data.orientation,
        image_data.position,
    )

    ele_center_values = self.interpolate_image_values_to_points(
        element_center_grid_coords, image_data
    )

    for i, ele in tqdm(
        enumerate(dis.elements),
        total=len(dis.elements),
        desc="Processing Elements",
    ):
        ele.data = ele_center_values[i]

        if np.all(np.isnan(ele.data)):
            self.nan_elements += 1

    self._log_interpolation_warnings()

    return dis.elements

Interpolates pixel values to finite element mesh elements using element centers.

This method assigns interpolated pixel values to each element in the Discretization based on its centroid. It first computes the centroid for each element, maps those coordinates to the image grid, and then retrieves the corresponding pixel values through interpolation.

Arguments

dis (Discretization): A finite element mesh containing elements and their associated nodes. image_data (ImageData): A structured representation of 3D image data, including pixel intensities, grid coordinates, and orientation.

Returns

list[Element]
A list of elements with interpolated pixel values assigned.

Inherited members