Unlock the Power of Extra Attributes with TerraScan
Point clouds can be considered to be tabular data, with each row representing a point and each column representing a different attribute. Certain attributes are common across all projects, while some are relevant only to specific sensors or use cases. For example, the LAS specifications define a standard set of point attributes that form the foundation for point cloud processing. These include:
- X, Y, Z coordinates
- Classification
- Return number
- GPS time
- Intensity
However, advanced and efficient workflows often benefit or even require additional information.
This additional point information must be stored in some way and the LAS format specifications include the definition for Extra Bytes to address this. These are flexible, user- or software-defined attributes that extend the number of attributes each point can have.
TerraScan has long been an industry leader in leveraging these attributes for enhanced point cloud processing and feature extraction. Since the early versions, TerraScan has introduced enhancements built around the utilization of these non-standard attributes:
- Groups (010.011)
- Dimension and Normal Vectors (012.015)
- Distance (016.022)
- unknown Extra Attributes (024.024)
The newest of these, the unknown Extra Attributes, enable users to define attributes directly in the TerraScan Settings dialog, making them available for use in point visualization, classification, and many processing tools. All attributes, standard or custom, can be manipulated with macro actions such as Set, Swap, Copy, and Clear.
These Extra Attributes enable points to have multiple attributes of any kind in the same file.
Example: Point cloud with two different distance attributes. Distance to ground (elevation from ground) and distance to reference point cloud 1 year later (larger distance means that the object does not appear in the reference point cloud).
A number of additional attributes defined by other software and hardware providers are supported by TerraScan as well. These include Riegl (Reflectance, Amplitude, Pulse width, Pulse shape deviation), Hovermap (Range), and Agisoft (Confidence) attributes. However, through the use of unknown Extra Attributes TerraScan is truly hardware-agnostic.
All attributes are supported in Fast Binary and LAS/LAZ 1.2+ formats. Additionally, TerraScan is able to parse Extra Attributes from user defined file formats.
With these and future enhancements, TerraScan improves the capacity of users to extract more value from every point.
YouTube video by Arttu Soininen covering this topic with a bathymetric data example:
Written by:
Lucas Magnusson
Sales Support Engineer at Terrasolid Ltd.