IN THIS ARTICLE
This article explains how to process laser scanner datasets in PIX4Dmatic. These datasets typically include images and point clouds captured simultaneously during the scanning process.
Handheld laser scanners are usually equipped with an IMU sensor, which continuously records the device’s orientation. This ensures that the orientation of the sensor is known for each capture. Some scanners also integrate a GNSS receiver to record the absolute position of each image.
If a GNSS system is not included, the dataset will instead rely on a local coordinate system that begins at the starting point of the measurement.
In both cases, the following data is recorded during acquisition:
- Point cloud
- Trajectory
- Images
- Image position and orientation file
How can I import the dataset?
- The dataset can be imported into PIX4Dmatic using one of the following two methods:
Drag and drop onto the Home screen: Simply drag and drop the images or the point cloud onto the Home screen, and PIX4Dmatic will automatically generate a new project using the imported point cloud.
File > Import > Images or Point clouds...: For an existing project, select this option to browse and import the desired images and point cloud.
- Once the data is imported, before creating the project, PIX4Dmatic will ask for the coordinate reference system.
How to use coordinate systems - PIX4Dmatic
How to use vertical coordinate systems and geoids - PIX4Dmatic - Image geolocation and orientation. Position and orientation of each image captured during the measurement.
How to import and export image geolocation and orientation files - PIX4Dmatic - During the importation of the dense point cloud, the acquisition type has to be selected as "With trajectory." The trajectory file contains detailed information about the path followed by the sensor during data acquisition, which is essential for georeferencing the LiDAR data.
Import point cloud - PIX4Dmatic
It is possible to import only the images or the dense point cloud, but depending on which data is imported, the following processing options will be available:
- Images.
- Before calibration: calibration and image-preprocessing.
- After calibration: dense point cloud, outlier removal, mesh, DSM, and orthomosaic.
- Point cloud: outlie removal and DSM.
How to process the dataset?
The workflow for processing a dataset from a handheld laser scanner starts with image calibration. Images captured with a handheld laser scanner typically resemble those acquired using PIX4Dcatch. To ensure optimal calibration results, the following configuration is recommended:
| Exterior | Interior |
 |
|
|
|
After calibration, access to the full set of processing options will be available, including dense point cloud, outlier removal, mesh, DSM, and orthomosaic. The same workflow we follow in a photogrammetric project.
In this case, a point cloud was also captured with a LiDAR that can be imported and used as part of the input data for processing.
- Dense point cloud. Imported.
- Mesh. To generate a mesh from the imported point cloud, image calibration is required to apply texture to the mesh. Processing the mesh is not possible without the associated images.
- DSM.
- Orthomosaic.
What else can I do?
Once the project is processed, it is possible to use all the tools avaibles on PIX4Dmatic.