/PointCloudCompression

Segmented PointCloud compression with DRACO, DBSCAN, Convolutional Autoencoders and 2D projection

Primary LanguageJupyter NotebookMIT LicenseMIT

PointCloudCompression

This project aims to provide an implementation of Point Cloud Compression (PCC) methods for segmented point clouds.

Developed together with Saverio Cavasin (@SvrCvs)

Task

Dataset

The dataset is the SELMA dataset, which is made by data collected by of 3 LIDARs located on a vehicle in a urban scenario. The location of the sensors is the following:

An example of the dataset is shown in the figure below:

The point clouds are segmented in different clsses, widely discussed here.

Strategies

1) DRACO [2]

is a compression library for 3D geometric meshes and point clouds. It is based on the Google Draco library, which is a general-purpose 3D geometry compression library.

2) DBScan

is a density-based clustering algorithm. It is a popular algorithm for clustering in a spatial context. The algorithm groups together points that are closely packed together (points with many nearby neighbors), marking as outliers points that lie alone in low-density regions (whose nearest neighbors are too far away).

3) Convolutional Autoencoder

trained to learn a representation (encoding) of a sample, with the lower possible loss in the reconstruction of the input data. The network is composed by an encoder and a decoder. The encoder compresses the input data into a lower dimensional space, while the decoder reconstructs the input data from the compressed representation. The architecture of the network is the following:

The training is done on 400 Point clouds of each class, and the test is done on 100 point clouds of each class. The results are the following:

Some examples of the reconstruction are the following:

4) 2D Projection [3][4]

Finally, we propose to change the coordinate system of the point cloud from cartesian to spherical and then project the point cloud on a 2D plane, whith a specific grid size. Some examples are the following:

References