image_dilate_erode#

UniformGridFilters.image_dilate_erode(dilate_value=1, erode_value=0, kernel_size=(3, 3, 3), scalars=None, preference='points', progress_bar=False)[source]#

Dilates one value and erodes another.

image_dilate_erode will dilate one value and erode another. It uses an elliptical footprint, and only erodes/dilates on the boundary of the two values. The filter is restricted to the X, Y, and Z axes for now. It can degenerate to a 2 or 1-dimensional filter by setting the kernel size to 1 for a specific axis.

Parameters
dilate_valueint or float, optional

Dilate value in the dataset. Default: 1.

erode_valueint or float, optional

Erode value in the dataset. Default: 0.

kernel_sizelist(int) or tuple(int), optional

Length 3 iterable of ints: (xsize, ysize, zsize). Determines the size (and center) of the kernel. Default: (3, 3, 3).

scalarsstr, optional

Name of scalars to process. Defaults to currently active scalars.

preferencestr, optional

When scalars are specified, this is the preferred array type to search for in the dataset. Must be either 'point' or 'cell'.

progress_barbool, optional

Display a progress bar to indicate progress. Default False.

Returns
pyvista.UniformGrid

Dataset that has been dilated/eroded on the boundary of the specified scalars.

Examples

Demonstrate image dilate/erode on an example dataset. First, plot the example dataset with the active scalars.

>>> from pyvista import examples
>>> uni = examples.load_uniform()
>>> uni.plot()
../../../_images/pyvista-UniformGridFilters-image_dilate_erode-1_00_00.png

Now, plot the image threshold with threshold=[400, 600]. Note how values within the threshold are 1 and outside are 0.

>>> ithresh = uni.image_threshold([400, 600])
>>> ithresh.plot()
../../../_images/pyvista-UniformGridFilters-image_dilate_erode-1_01_00.png

Note how there is a hole in the thresholded image. Apply a dilation/ erosion filter with a large kernel to fill that hole in.

>>> idilate = ithresh.image_dilate_erode(kernel_size=[5, 5, 5])
>>> idilate.plot()
../../../_images/pyvista-UniformGridFilters-image_dilate_erode-1_02_00.png