Questions tagged [point-cloud]

A point cloud is an unstructured set of points, each defined by x,y,z co-ordinates.

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8
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4answers
3k views

Thinning large LiDAR point cloud?

I have a large point cloud (LAS file) and I am trying to thin this using a complex technique. I know it is possible to thin a point cloud using simple techniques such as extracting every nth point. ...
10
votes
8answers
4k views

Editing LiDAR point cloud to remove noise/outliers present below and above ground?

I have "dirty" LiDAR data containing first and last returns and also inevitably errors under and over the surface level. (screenshot) I have SAGA, QGIS, ESRI and FME at hand, but no real method. What ...
5
votes
1answer
2k views

GeoReference XYZ point cloud

I am looking for help. I have done a little bit of geo-registration of images with QGIS. But now, I have been handed some LIDAR data in PCD format (basically x,y,z), But it is not geo-referenced. I ...
4
votes
3answers
607 views

Open source approach to classifying and removing LiDAR points from overlapping scans?

The attached screenshot shows a LiDAR point cloud with significant overlapping scans. This point cloud tile is part of the MN statewide LiDAR dataset which has 25% scan overlap and 1.5 NPS. For many ...
2
votes
1answer
551 views

Why ground model from point cloud in Global Mapper is inaccurate?

I have a LAS file that I assumed was based on LiDAR, but it is actually based on ADS (airborne digital sensor) imagery, according to the body that captured the data. I load the file in to Global ...
5
votes
1answer
360 views

Georeferencing terrestrial LiDAR point cloud?

Recently I took a Faro Focus terrestrial laser scanner to a forested area and collected multiple scans for 12 fixed radius plots. Each plot had 5 GPS points collected within it in hopes to ...
3
votes
2answers
872 views

Generating DEMs from point clouds and differencing them?

I have two point clouds obtained via structure from motion (ground photos of sand-dunes + Visual SfM/Agisoft Photoscan). If I wanted to generate a DEM from these point clouds and difference them to ...
2
votes
1answer
872 views

Georeferencing LIDAR scans in CloudCompare?

I've got several LiDAR scans in local coordinates (point cloud with an arbitrary 0,0 as origin) that I would like to reference to real world coordinates. I've tried to Align the scan in CloudCompare ...
1
vote
0answers
292 views

Flipped (Y-axis) Raster from point cloud

I have been working on a project where I need to create rasters from irregularly spaced point clouds. I am resampling my point clouds to a regular 0.25 cm grid using a nearest neighbor method ...
1
vote
1answer
168 views

Visualizing extra bytes from LAS 1.4 in Potree?

I was wondering if it is possible to visualize the information that can be stored in the extra bytes of the LAS 1.4 file. This could be really helpful for validating features that have been calculate ...