13

It sounds like you want either a voxel-based thinning or maybe a Poisson-based one. PDAL can do either. See PDAL's tutorial on the topic at https://pdal.io/tutorial/sampling/index.html . As far as the size of the file, please define "large". Just about any technique except simple rank decimation (remove n-th points) is going to want to have access to the ...


9

You seem to have outliers: i) below the ground surface; ii) above the ground surface and vertically among other above ground real features; iii) above ground points with height greater than all objects of interest, for example the ones caused by clouds or birds (this is not shown in the picture, but I am assuming it might also be the case). For 'i', the ...


8

I've done this before with success using the Photosynth Toolkit (http://www.visual-experiments.com/demos/photosynthtoolkit/), except instead of a drone I was hanging my head out of a small plane taking pictures of the downtown area of a small town. You could also check out Visual SFM (http://ccwu.me/vsfm/); I haven't used it but it seems to be another tool ...


7

Dark areas = low reflectivity. Light areas = high reflectivity. My guess is the dark squares simply has not reflected light back to the transceiver and then you have no xyz data here. For the floor my guess is that light is deflected away from aperture and not towards aperture, except for the holes. This depends of course of the sensor and the setup. In ...


6

You can give lasthin or lasduplicate from LAStools a try. With lasthin you can keep the '-lowest', '-highest', '-random', or most '-central' point on a 2D grid in the x/y plane with user-defined '-step 0.5' size. With lasduplicate you can specify to remove all points that are '-nearby 0.005' in 3D from all previously appearing points. See the linked README ...


5

PDAL supports a similar workflow, and it allows you to use any OGR-readable data source for the polygons. There is a tutorial on the PDAL website that describes how to do it. You can use Docker to run PDAL command-line utilities on Windows 10, and the PDAL Quickstart has details how to get that going. In short, the workflow in PDAL for this task is to: ...


5

This is not natively possible yet in lidR! But R is a programming language so you can write your own algorithm to achieve this task. If you can do that please share with the community it could be useful ;-). I think LAStools has such tool.


4

The filters.voxelgrid filter requires PCL support, which it doesn't appear you have linked. On OSX, Homebrew PCL (1.7.2) should be sufficient. See my configuration script for hints on how to have CMake use it. Another easy way to get going with PDAL is to use Docker. It contains a fully-featured PDAL build. The PDAL Docker latest image based on last stable ...


4

First, for the answers proposed here, you probably do not want to use the ferry filter to push HeightAboveGround to Z, at least not prior to segmentation, as the act of normalizing heights involves subtracting an interpolated estimate of the ground elevation from each return. Something planar in the original X, Y, Z space may no longer be planar in the ...


4

There are a couple of options. Depending on the area of MN where you're processing, the overlap areas of the data are classified, and you can use a PDAL filters.range to cull them out: pdal translate input.las output.las range --filters.range.limits="!Classification[12:12]" (inspect and visualize that in your browser here) Not everywhere has these nicely ...


4

I've never used a Faro Focus but I do own a Leica C10 ScanStation and I imagine that the process of merging point clouds is similar for all terrestrial laser scanners. You generally need to have three or more tie points between pairs of point clouds captured, with each point cloud derived from a single scan station. In the case of my system, there are ...


4

If you want to use a UTM-like projection that isn't a standard UTM zone, you can just specify your own Transverse Mercator coordinate system. Here's the PROJ.4 page on Transverse Mercator projections. If your grid origin is known in geographic Longitude, Latitude coordinates, your projection will look like: +proj=tmerc +lat_0=ORIGIN_LAT +lon_0=ORIGIN_LON +...


4

Short answer: No. And more specifically lidR is designed for ALS primarily, if ever I add a function for noise removal it will be for ALS first.


3

This is actually a multi-step workflow. First you need to create polygons or a raster mask of the areas you would like to clip/mask. Then either reclassify or clip the point cloud with the polygons. Lastools lasclip can accomplish this. I have not used lastools via QGIS, although I know this is possible (instructions). lasclip takes as input a LAS/...


3

Probably they have made a structure from motion function. With the mosaic of several pictures around an object you can create its 3d model and get also the point cloud. Thats nothing too spectacular. Probably the calculations are made in the cloud and sent back to the device for the "near real time". For example VirtualSFM is a extremly strong opensource ...


3

There was a bug in the PMF filter that has been fixed in newer versions of PDAL that was causing this. Try PDAL 1.1+ to get past this issue. If you still have trouble, please ask on the mailing list.


3

You might check whether or not the C10 .bin file is actually a TerraSolid file. PDAL provides a reader for TerraSolid .bin plus numerous other point cloud formats.


3

BPF is rather new as a public format. PDAL supports both reading and writing BPF data. You can use the OSGeo4W64 build of PDAL to translate the data into LAS 1.4 using the following command: pdal translate simple-extra.bpf out.las \ --writers.las.minor_version=4 \ --scale 0.01,0.01,0.01 PDAL will write commonly-named dimensions, such as XYZ into ...


3

PDAL can do this for you, but not automatically. You need to use something to compute your transformation matrix and then apply the transformation matrix with PDAL's filters.transformation filter. Once you have your transformation matrix, you can use the transformation in a pipeline as shown in the example. OSGeo4W64 is a binary distribution for Windows ...


3

What is the format of your file? If you have a .ply, there is a new module of GRASS GIS that allows geo-referencing of points cloud in this format: v.ply.rectify. Here are the quick instructions: Create a .txt file with source and target coordinates; save the file with the same name as the point cloud in the same folder. Open v.ply.rectifiy in GRASS GIS 7, ...


3

Be aware that .las and .obj are not the same type of data, in which the first is composed by points, and the second is a type of surface. So, even processing the point cloud to output a surface it is needed that the points in the .las file make sense to what is being generated. For example, triangulating first returns (for DSM) or last returns, or returns ...


3

In the latest release of the open-source geoprocessing platform WhiteboxTools (v. 0.7) I just added a new tool called ClassifyOverlapPoints that classifies or filters LAS points in regions of overlapping flight lines. If the --filter flag is specified, points from overlapping flightlines (i.e. later GPS times) are culled from the output point cloud. If this ...


2

You can use FUSION's ThinData command for this (Documentation p.130). ThinData is really handy because it allows you to thin point cloud data to a desired pulse density per square unit. From FUSION's documentation: ThinData [switches] OutputFile Density CellSize DataFile ThinData allows you to thin LIDAR data to specific pulse densities. This ...


2

-https://www.mapsmadeeasy.com/point_estimator you can use this to make a flight plan set variables to what you want make sure to pick inspire/phantom 3 as camera near the bottom, you can export this plan as kml for apm. or if you are more adept you can use the gis software of your choice to create a kml grid flight path for upload to litchi in the following ...


2

I think a way to do this is VisualSFM to do the matching of the photos (the stronger the GPU the better) and creating a dense point cloud and MeshLab to create a textured triangulated model from the point cloud. VisualSFM: http://ccwu.me/vsfm/ http://ptak.felk.cvut.cz/sfmservice/websfm.pl?menu=cmpmvs (cp. especially the 'Technology' site and the paper ...


2

Further to Jeffrey Evans' answer, you could use PDAL to classify the ground points. It's a little harder to get started (on Windows, anyway) but it's free and makes high-volume batch-processing a cinch.


2

If the class codes field is not populated there is no way to obtain them. During pre-processing the vendor did not classify the points so, you are functionally dealing with a raw point cloud. Unfortunately, this means that you need to start researching methods for classifying the point cloud yourself. Since you did not provide any context I cannot aim you ...


2

You want to remove non ground points in the scene, but your LiDAR cloud is unclassified. Therefore, instead of doing this manually, use some customized tools for such tasks. For classifying the point cloud between ground and non ground points, see: Determining bare earth DEM from unclassified LAS file? And for keeping only the ground points, see: Keeping ...


2

here's some good news for you! In the latest version of Pix4Dmapper, the volume is calculated based on the DSM if the 3rd step - DSM and Orthomosaic generation is done. This is done by default, and users do not have to change any settings! Please stay tuned :) Lisa


2

I'm guessing that you're seeing quantization - the output comes out looking "terraced", like rice fields. If that's the case it's because you're outputting 8 bit png, which only has 256 possible values. you can do this with the command line tool gdal_translate. You should be able to run this from the terminal (linux/mac) or the osgeo4w shell (windows). I ...


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