Point cloud tools for Matlab

Currently included are:

pointCloud class	a Matlab class to read, manipulate and write point clouds
globalICP class	a Matlab class to optimize the alignment of many point clouds with the ICP algorithm

Download Matlab Code

1. Download this zip archive and extract it into an arbitrary folder, e.g. D:\MyMatlabCode\pointCloudTools.
2. Add this folder to the search path in Matlab:

   addpath(genpath('D:\MyMatlabCode\pointCloudTools'));

3. Finally, check if it is working by running:

   pc = pointCloud('Lion.xyz');
   pc.plot;

The code is hosted on GitHub. It is also available on Matlab File Exchange.

pointCloud class

This is a class for processing point clouds of any size in Matlab. It provides many functions to read, manipulate, and write point clouds. Check out some of the functionality in this introductory tutorial.

Tutorials

• Intro: Working with the pointCloud class in Matlab
• How to select a subset of points
• Thin out a huge point cloud (download data here)
• Select points on the basis of a GeoTiff file (download data here)

Documentation

Class methods:

pointCloud	Import of point cloud data.
select	Select a subset of points.
plot	Plot of point cloud.
normals	Compute normal vectors of activated points.
plotNormals	Plot normal vectors of point cloud in 3d.
info	Report informations about the point cloud to the command window.
transform	Coordinate transformation of point cloud.
export	Export activated points to a file.
save	Save point cloud object as mat file.
reconstruct	Reconstruct object only with active points.
getVoxelHull	Compute the voxel hull of a point cloud.
addAttribute	Add an attribute to the object.

globalICP class

With the globalICP class the alignment of two or more point clouds can be refined by the Iterative Closest Point (ICP) algorithm. A prerequisite for this is an approximate alignment of the point clouds.

Documentation

• General description of the method
• Advanced selection strategies for correspondences

Class methods:

globalICP	Constructor method for global ICP class.
runICP	Run ICP algorithm.
addPC	Add a point cloud to globalICP object.
loadPC	Load point cloud to workspace.
exportPC	Export a point cloud.
plot	Plot all added point clouds.

Tutorials

• Simultaneous alignment of six point clouds
• Simultaneous alignment of three TLS point clouds
• Simultaneous alignment of three ALS point clouds

Version for Windows command line

If you are not familiar with Matlab, you can use a compiled version of the ICP algorithm on the Windows command line:

• Helpscreen
• Download here
• Requires the installation of the MATLAB Compiler Runtime for the release version R2016a
• Example with data in folder "demodata":

  ICP -inFiles demodata\lionscan*approx.xyz -UniformSamplingDistance 2 -PlaneSearchRadius 2 -Plot 1

Related Papers

• Glira, P., Pfeifer, N., Ressl, C., Briese, C. (2015): A correspondence framework for ALS strip adjustments based on variants of the ICP algorithm. In: Journal for Photogrammetry, Remote Sensing and Geoinformation Science (PFG) 2015(04), pp. 275-289. DOI: 10.1127/pfg/2015/0270
• Glira, P., Pfeifer, N., Ressl, C., Briese, C. (2015): Rigorous Strip Adjustment of Airborne Laserscanning Data Based on the ICP Algorithm. In: ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-3/W5, pp.73-80. DOI: 10.5194/isprsannals-II-3-W5-73-2015.