Polygons spike removal application

A Python application to remove spike from polygons

Description

This tool can be used to remove spikes from input geometries stored in geopackage format. This is done by parsing the input geometry and evaluating each set of three contigous vertices against an evaluating strategy and removing from the output geometry the vertices that fail to pass the test.

Example original gpkg file

Output of the gpkg file after running the tool

Installation

This tool single external dependency is geopandas.

Installation of the python-polygons-spike-removal tool can be done by cloning this repository as follows:

$ git clone https://github.com/Mathewsmusukuma/python-polygons-spikes-removal.git
$ cd python-polygons-spikes-removal
$ pip install -r requirements.txt

Usage

Simple example of using this tool to process a file:

$ python3  main.py -o data/spiky-output.gpkg data/spiky-polygons.gpkg

Flowchart diagram for the algorithm for the spike removal application

To run tests

pytest -v

Note

You can update the dataset in the data-file directory.

For more details run python main.py --help:

Usage: spike_removal [OPTIONS] FILENAME

  A command-line tool used to remove spikes from polygons stored in
  Geopackage format.

Options:
  --angle FLOAT      Maximum angle, in degrees, used to evaluate spikes.
                     Defaults to 1.0º.

  --distance FLOAT   Minimum distance, in meters, used to evaluate spikes.
                     Defaults to 100 000m

  -o, --output TEXT  Name of the output destination file  [required]
  --help             Show this message and exit.

The tool accepts three diferent input arguments:

• --angle: The maximum angle, in degrees, that will be used to evaluate triplets of vertices. If the triplet being evaluated forms an angle greater than the value of angle, that triplet will never be marked as a spiked. The value of angle defaults to 1.0º if not specified.

• --distance: The minimum distance, in meters, that one of the edges of the triplet being evaluated must have for that triplet to be tested as a spike. The value of distance defaults to 100 000 meters if not specified.

• --output: The output path where the processed geometry will be saved to.