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Questions tagged [las]

An industry-standard binary file format that maintains information related to lidar data.

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11 votes
4 answers
11k views

Determining bare earth DEM from unclassified LAS file?

I have data in LAS format with RGB values created from aerial photogrammetry using a UAV. I am trying to find a solution to extract the bare earth DEM from the point cloud. I have tried SAGA, ...
user32307's user avatar
  • 111
11 votes
5 answers
20k views

Clipping LAS data using shapefile polygons and open source software?

I am trying to clip or filter lidar files (.las, .xyz) using a shapefile that contains multiple polygons. Is there open source software that can do this spatial operation? My .las files are enormous,...
Allen Bustenai's user avatar
8 votes
5 answers
22k views

Creating DEM from LAS file without using LAStools?

I want to create a ground model from a *.las file. The LAStools are available in QGIS but limited in use (generation of black diagonal in result file), so I can't use this. In the GRASS tools I can ...
David M.'s user avatar
  • 159
9 votes
4 answers
7k 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. ...
Bodkinz's user avatar
  • 147
4 votes
1 answer
2k views

Rescaling and reoffsetting a point cloud with lidR?

I'm trying to analyse a a 3 x 3 metres scan derived from terrestrial photogrammetry (i.e. local coordinates, with 0,0 in the centre of the point cloud) to obtain a DSM. Importing the file in lidR, I ...
Nico's user avatar
  • 305
13 votes
3 answers
55k views

Converting LiDAR files from LAZ to LAS format

I'm trying to convert LiDAR files from the LAZ format (the compressed version) into LAS (the uncompressed version) using LASzip software. However, I am not really sure how it works. I created a new ...
June's user avatar
  • 287
7 votes
2 answers
8k views

Converting TIFF file to LAS file in QGIS?

I've been asked by a client to compile LiDAR files (currently in GeoTiff format) into a LAS dataset. Is this possible within QGIS? I have downloaded LAStools, but I'm still fairly new to LiDAR so ...
E Forsyth's user avatar
  • 113
4 votes
2 answers
1k views

Classifying raw LAS data as bare earth in ArcGIS for Desktop?

I have a raw LAS data that has only one return (no second/ third.. return) and not classified yet. The only information I have is intensity and elevation. Is there any way that I can classify bare ...
June's user avatar
  • 287
3 votes
1 answer
1k views

Clipping LAS data with multiple shapefiles

I am looking for a method to clip with multiple shapefiles (139 shapefiles polygon) a lidar.las file. I'm using the software Fusion, as described in: How to clip LAS data using shapefile polygons ...
Wan S's user avatar
  • 71
2 votes
2 answers
559 views

Pixelated DSM using LAS Dataset to Raster?

I am using ArcGIS 10.2.2, and I am trying to create a DSM out of some LIDAR data. After checking the LAS Dataset properties, I see that I have an average point spacing of approx 0.3. I tried ...
DOMINUS MIHI ADIUTOR's user avatar
27 votes
6 answers
40k views

What LiDAR processing tools are available in Python?

I have been using FUSION and the command line FUSION Lidar Toolkit (LTK) to process LiDAR data. A broad Google search ("Lidar Python") yielded libLAS and pyLAS as Python LiDAR libraries, however, ...
Aaron's user avatar
  • 51.7k
13 votes
3 answers
8k views

Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?

From time to time, we use LiDAR data for modelling in ArcGIS. Previously, we would be supplied either an .xyz or .ascii of the data, but more recently, we are also being provided .las files in ...
TsvGis's user avatar
  • 2,079
6 votes
1 answer
5k views

Converting LAS 1.4 to 1.2

LIDAR files were released for major part of Slovenia few months back in zlas format. Decompressed LAS format is 1.4 version. I have tried many options how to generate DEMs and had some success in ...
Jost Hobic's user avatar
4 votes
1 answer
684 views

How to use lastrees on a catalog with a function requiring a CHM raster?

I'm still fairly new to using LiDAR data and R, so please let me know if this isn't clear. I am using the lidR package to segment individual trees over a large landscape. I have been using the ...
KLH's user avatar
  • 155
3 votes
2 answers
3k views

Python-PDAL: error reading Format 1.4 LAS File - (readers.las Error) Global encoding WKT flag not set for point format 6 - 10

I am using python-pdal 2.4.2 to read a LAS 1.4 in PointFormat 8, with the objective or using different writers stages afterwards. The pipeline is simple: import json import pdal filepath = "path/...
CharlesG's user avatar
  • 223
3 votes
1 answer
2k views

Classifying above ground LiDAR points in ArcMap?

I recently used the LAS Dataset toolbar to classify a .lasd file. The process classified the majority of points as unassigned with the rest being ground points. The study area has many tall buildings ...
NHorner's user avatar
  • 31
3 votes
2 answers
5k views

Converting from shapefile or raster formats to LAS? [closed]

I am looking for a solution to convert either from ESRI shapefile format to LAS or from a common raster format to LAS. I have access to following software: ArcGIS 10.2 for Desktop (arcinfo with ...
Jordan Walker's user avatar
2 votes
1 answer
3k views

Merging more than 9 input files with lasmerge?

Is there a possibility to feed more than 9 LAS files to lasmerge tool? The user interface only allows 9 LAS files from LAStools toolboxes in QGIS or ArcGIS, but at liblas.org it’s described as there ...
Thomas Becker's user avatar
2 votes
1 answer
340 views

Batch processing LiDAR files (.las to raster) with PyQGIS?

for layers in glob.glob("*.las"): processing.runalg("grass7:r.in.lidar", "input_las",5,1,"",1,100,"","",5,"","",False,True,True,"331289.57265,337990.42735,4558790.0,4560890.0",0,layers+"E:/...
RK4gis's user avatar
  • 101
13 votes
6 answers
18k views

Creating boundary polygon shapefile from set of LAS files using ArcGIS Desktop?

I have a bunch of LAS file sets that I need to process. The current task at hand is to generate a "footprint" shapefile that contains polygons for each LAS tile. I am looking for a graceful way to ...
conroymedeiros's user avatar
9 votes
0 answers
504 views

Seeking open raw LiDAR or laser scanner data? [duplicate]

I'm looking for aerial LiDAR or terrestrial laser scanner data in laz or las format preferably from an FTP site. Does anyone know which countries have that data available to the public? From my ...
7 votes
4 answers
9k views

Use laspy to create las file from scratch without opening an existing las file first

I have found instructions for creating a las file by opening an existing file, modifying it, then re-saving it. This re-uses the headers from the original file. How do I create a new file from scratch ...
pythonjsgeo's user avatar
7 votes
1 answer
10k views

Finding the coordinate system info from a LAS/LiDAR file with Python?

I found several examples of how one can query and manually set a coordinate system on a tif/raster file (GDAL/Python: How do I get coordinate system name from SpatialReference? or Is it possible to ...
spartmar's user avatar
  • 563
5 votes
2 answers
1k views

Overlapping LAS tiles

I have a las catalog with overlapping tiles. LidR warns me of this, and I'm wondering how concerned I should be. The tiles are in las version 1.2 with point record format 1. None of the points are ...
Lucas's user avatar
  • 613
3 votes
1 answer
699 views

Georeferencing las files using liblas

I am trying to write georeferencing information to a '.las' file using liblas and c++. Here is my code: ofstream ofs; ofs.open("test.las", ios::out | ios::binary); liblas::Header header; ...
cpiury's user avatar
  • 315
3 votes
2 answers
2k views

Change projection for LAS file

I have read a LAS file. If I import it in Global Mapper it says the projection, however when I read it with laspy (header.proj_id_1) there is no information associated. I have edited the coordinates ...
Paul Nicoara's user avatar
3 votes
1 answer
1k views

Clip multiple .las files data to polygon shapefile using FUSION

I followed this thread in order to clip .las data based off of a polygon shapefile. However I have over 100 .las files I need to clip based off of this polygon and merged into a single .lasd file and ...
cbunn's user avatar
  • 1,417
3 votes
3 answers
3k views

Can ArcGIS Desktop create LAS (or lasd) files from ASCII data?

I have many ASCII files containing LiDAR xyz values. In order to create an ArcGIS LASD file, I need to convert these ASCII files into las files. I can do this with FME or LAStools, but I can't see a ...
Robert Buckley's user avatar
2 votes
2 answers
5k views

LAS dataset to raster with ground points only [duplicate]

I'm trying to make a raster from an LAS dataset. I want to only use points classified as ground, but I can't figure out how to do this. What I've tried is: Create LAS dataset from 2 .las files. ...
Johan's user avatar
  • 163
2 votes
1 answer
1k views

Update EVLR header info for .LAS file using laspy

I'm trying to change the header info for a LAS file using the python 2.7 (64-bit) laspy module (version 1.2.5). I'm attempting to follow the example shown here (in the section "Writing Data + EVLRS"): ...
Andrew's user avatar
  • 201
2 votes
3 answers
1k views

Laz LiDAR files displaying extremely long thin line of points

I am having difficulty properly visualizing aerial LIDAR data from the csc.noaa.gov source. Taking any of the .laz files, the point cloud displays as an extremely long thin line of points. Zoomed in, ...
user25226's user avatar
1 vote
1 answer
2k views

Keeping only ground points (class 2) with lasground in QGIS 2.14?

I want to keep only the LiDAR ground points in a las file, using the lasground tool from LAStools within QGIS. In QGIS Chugiak (2.4) there used to be an option to "keep class 2", but I don't know how ...
user66349's user avatar
  • 149
1 vote
2 answers
4k views

Adding RGB values to Laspy synthetic point generation?

What is the correct way to add RGB values to points made from scratch? Laspy is working great for me so far. I want to add RGB values to synthetic points that I've generated. I am using 2 numpy arrays....
Cary H's user avatar
  • 976
1 vote
2 answers
11k views

Exporting coordinates from LAS files to CSV?

Is there any tool available for extracting the X, Y and Z coordinates from a .las file and exporting them to a .csv or similar file?
Dan D.'s user avatar
  • 153
1 vote
5 answers
3k views

Exporting ground returns (.las) from classified point cloud?

I have lidar data that is classified as several categories (water, ground etc.). I need to open this lidar data in some software (it will be great if it would be a open source software) and delete a ...
Jaumenik's user avatar
35 votes
2 answers
18k views

LAS to DEM conversion [closed]

I regularly come across LiDAR (.LAS) files with elevation data. When I do, I always struggle to find a way of converting them to a DEM for hydrological analysis. I have developed several workflows, ...
Martin's user avatar
  • 4,928
8 votes
1 answer
1k views

Rescaling LAS file with lidR package in R? [duplicate]

I am trying to process a large .las file received, which appears to have been scaled in non-standard ways for some reason (likely data transfer portability). The scales between x, y, z are different ...
Rob's user avatar
  • 183
6 votes
4 answers
2k views

How to filter LiDAR data by scan angle?

I am looking to filter LiDAR data (.las format) by scan angle specifications (e.g. keep all points < 15). From a basic Google search, it appears that the libLAS library has the ability to filter by ...
Aaron's user avatar
  • 51.7k
6 votes
2 answers
2k views

Extracting RGB values from aerial photo and assigning to LAS file with FME?

I need to extract the RGB Values from imagery and assign to a .las file in order to display 3d landscape with "real" colours. I have an unlicenced LAStools, FME 2017 and ArcGIS 10.3.1 at hand. I ...
Robert Buckley's user avatar
5 votes
2 answers
7k views

Adding LAS files into AutoCAD map 3D with Point Cloud Manager tool

It's my first time to use AutoCAD map 3D for LiDAR. Based on my googling, it is said that I can bring .las file by creating new index and using the Point Cloud Manager tool (the image on the top - ...
June's user avatar
  • 287
5 votes
0 answers
372 views

Maintaining extra data for .laz for use in R and Python?

I am working on releasing a benchmark dataset for trees in RGB + Lidar and I'd like the format to match the most common use cases and packages. I had been intending on proving a tree index using the ...
bw4sz's user avatar
  • 363
5 votes
1 answer
3k views

When to reproject LAS data?

I've downloaded a few LAS files from the NOAA: http://www.csc.noaa.gov/digitalcoast/data/coastallidar I used lasinfo to get the coordinate system of the LAS files and it returned: ...
geogeogeo's user avatar
  • 581
5 votes
1 answer
304 views

Unusual polygon shapes when using tree_hulls?

The following script uses lidR to segment trees and output tree hulls (i.e. polygons representing individual tree canopies). Input data are a directory of laz files and a catalog is used to manage the ...
Aaron's user avatar
  • 51.7k
4 votes
1 answer
952 views

Converting LAS data from buildings to detailed shapes using ArcGIS Pro?

What we want to achieve is to convert LAS data to a GIS format like shapes. On the internet, there are enough examples how to convert the LAS data height to a building footprint. What we want is ...
Joska Paszli's user avatar
4 votes
2 answers
2k views

What's the deal with "degradation" and lastools?

I've read a few cautions online and heard a few from colleagues. If you don't purchase a license for lastools, the non-open-source functions will somehow degrade your data or results? Is this true? ...
J Kelly's user avatar
  • 1,373
4 votes
0 answers
135 views

Getting NIR values into LAS file then CSV? [duplicate]

We are trying to deliver a LAS file with NIR values added for each point. The NIR comes from a raster captured at the same moment as the LiDAR, and is stored as an 8bit number along with RGB in 8bit. ...
user25644's user avatar
  • 1,089
4 votes
2 answers
8k views

Reading LAZ file in Python directly?

I am able to read .las file in Python using laspy in Windows as below: las_filename = 'abc.las' inFile = laspy.file.File(las_filename, mode='r') But when I put a .laz file in this code, I get the ...
Sajjad Manal's user avatar
3 votes
1 answer
6k views

Converting .ply files to .las for ArcGIS input?

I'm trying to open a .ply file (point cloud in ArcGIS Desktop and ArcGIS Pro), but I can't. How can I convert the .ply file to .las, or open .ply in ArcGIS Desktop or ArcGIS Pro?
Rida Chams's user avatar
3 votes
1 answer
4k views

Visualizing LAS with matplotlib

I'm trying to create a 3D scatterplot using an las file that contains xyz and return values. I want to keep all returns but would like to subset the cloud. I've learned how to subset using laspy so no ...
user95191's user avatar
  • 453
3 votes
2 answers
10k views

Converting .las to .pcd file using PDAL?

Is it possible to translate .las files to .pcd with PDAL? If so, using which tool? I need an example about how to set the command-line with such tool. If it is not possible (or alternatively), is ...
ahmad735's user avatar
  • 133