Filters - Dev

This page contains useful information for developers who want to modify / add content to the filters module.

First of all, two points of advice:

  • Use the existing filters as guideline.
  • Follow the general CONTRIBUTING GUIDELINES.

The Big Picture

Filters are used by the method:


Take a look at the source code in order to get a general overview of how filters are being used. All filters are classes and all have the same methods.

The sections below will guide you trough the filters module explaining how you can create your own filters or where you need to look in order to modify existing ones.

Base Class

All filters must inherit from the base class Filter and implement its abstract methods.

The base class is located at pyntcloud/filters/

class pyntcloud.filters.base.Filter(*, pyntcloud)[source]

Base class for filters.

At the very least, all filters receive a PyntCloud when they are instantiated.

The Filter.extract_info method must be overridden in order to extract and save the information required to compute the filter in a attribute.

See SUBMODULE BASE CLASS below for more information.

Filter.compute is where the boolean array is generated and returned. It should use the information extracted by the above method in order to decide which points should be filtered.


Submodule Base Class

Filters are grouped into submodules according to which kind of information they require to be computed.

For example, filters that require a KDTree to be computed are in pyntcloud/filters/

As the information required by all the filters in each submodule is the same, we create a submodule base class overriding the __init__ and extract_info methods of the Filter base class.

For example, in the f_kdtree submodule there is a Filter_KDTree class from which all the filters that require a KDTree inherit.

If you don’t find a submodule that extracts the information that your new filter needs, create a new one using as guideline one of the existing ones.

Specific Filter Class

Once you have a submodule base class that extracts the right information, you have to actually create the specific class for your filter, inheriting from the submodule base class and overriding the Filter.compute method.

If the computation of your filter requires some parameters from the user, you should override the __init__ method in order to accept those parameters.

For example, the RadiusOutlierRemoval filter requires the user to specify a radius “r” and a number of neighbors “k”:

Let PyntCloud know about your filter

In order to do so, you have to do some things:

  • Add tests at test/
  • Import your new filter(s) and/or submodule(s) at pyntcloud/filters/
  • Include them in the ALL_FILTERS dictionary, giving them a string alias at pyntcloud/filters/
  • Document them in the PyntCloud.get_filter docstring at pyntcloud/
  • Document them at docs/filters.rst.