Questions tagged [las]

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

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Function voxel_metrics in lidR 4.0.1 gives error "Argument is not a LAS object" when used with a LAScatalog

I am attempting to use the lidR voxel_metrics() function to compute leaf area density across a large spatial extent. Due to the size of the LAS file (~10 GB) I have imported it as a LAScatalog object ...
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LAS2DEM QGIS No Results

When I try use LAS2DEM in QGIS, the results are an empty file: I have followed all setup instructions with the LAStools zip folder (in a C:\ with no spaces or special characters in the path, and set ...
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Potree : Save user interactions

I am a new user of Potree and I would like to know if anyone has already an idea or found a way to save a user's interactions on Potree and use them again. For example: if the user added an annotation ...
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Ground Classification, without any classified data? (Laspy, Python)

I am trying to classify ground point in .las file. Points are never classified which is 0. I read something about, if the number of return is 1, we can declare it as ground. Is it true? las....
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Problem with opening .las files in QGIS

For the last few days I tried to open .las Files from my work into QGIS. I have heard that the newest version of QGIS is able to open .las .laz files without any problem. The problem is that the ...
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las2las - Reproject (shift) from shifted X,Y projection to original projection

I have a .las projected in a shifted EPSG:2100 projection. Coordinates are shifted by X,Y as following: X: 58xxxx -> xxxx Y: 414yyyy -> yyyy For EPSG:2100, projection parameters are given here:...
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Do i lost precision when importing LAS files with PDAL?

I check pdal info and see that bbox has 15 digit numbers: "boundary": { "type": "Polygon", "coordinates": [ [ [ 1528634.540273188613355, 403421.710437842586543, ...
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entwine build produces a strange value for bounds in ept.json

I am relatively new to entwine. In our project, we have a requirement to build entwine from Laz dataset in EPSG:4326. I understand it might sound weird that we have this dataset in geographic ...
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LiDAR: Classify overlap using Whitebox removes points in non-overlapping areas

I'm trying to classify/remove flight line overlaps in .las-files using the Whitebox toolset. The LAS file has a band in the centre where two flight lines overlap. When I run wbt.classify_overlap, the ...
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Convert .LAZ to .LAS without LAStools or command line (QGIS 3.22.4)?

Is it possible to convert .LAZ to .LAS in QGIS (without LAStools)? Tools such as r.in.lidar (GRASS) used for conversion of point cloud to raster require .LAS as input, but after much searching around, ...
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Using LasPy to create a new LAS file based on another, while preserving geographic location of the points?

I have an input LAS file that has lots of points, that also includes RGB and other info besides the XYZ. My goal is to select only the XYZ of the ground points, preserving the geographic location, ...
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PDAL LAS writer, how to set the writer as a output stream?

I have a C++ script for my lidar data processing and map building. However, there is no example to set the output stream. So how should I set up the output in the calculation function? The code is ...
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Are RGB values encoded/recorded in raw LAS/pointcloud data?

RGB info in the pointcloud: Is this always from a post-processing step (e.g. using imagery overlay techniques to do so) or does it in some cases come from the machine/sensor which recorded the LAS?
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Creating Raster from LAS tiles [closed]

In ArcGIS, I'd convert LAZ --> LAS... then "Create LAS Dataset" and finally "LAS Dataset to Raster" Can someone help a brother out and drop the process to get me from point to ...
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Points in Polygon extraction

I have a shapefile with MSK-16z2 crs and a las-file which crs can not be recornized by qgis, but attached to the las prj contains also MSK-16z2. I need to crop described lasfile by shapefile. I tried ...
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LASTools file - conversion - laszip produces no output

I'm trying to convert a LAZ to LAS and am using LASTools laszip tool to get it done, but it won't produce an output. Here's what I get: Any suggestions?
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Where is the "Display file name" option for a LAS dataset in ArcGIS Pro?

In ArcMap, I can easily label the file name for a LAS dataset through the layer properties. In ArcGIS Pro I can only see limited options. Is there any way of labeling the file name?
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3 answers
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Generating DEM from multiple, adjacent .LAS files using QGIS

I have less than a dilettante's knowledge of GIS, but a friend showed me a Digital Elevation Model (DEM) image of some land and I thought that I would like to give it a try. I downloaded the latest ...
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Reclassify points within a bounding box with PDAL

I have a list of 3D bounding boxes manually drawn around noise points and I want to reclassify them as noise. One option would be to simply drop them but, in this particular case, I would want to have ...
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Using pdal filters.divider to split LAS into multiple xyz-files

I'm runnig a pdal pipeline to do some pointcloud processing and finally I want to write to multiple xyz-files using the filters.divider. It works as expected if writing to Las-files using type: writer....
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PyShp cuts the shapefile

I have a .las file and .shp file with polygons. The shapefile looks like follows: For each polygon, I calculated statistics based on elevation data vertices from the .las. Now I want to add fields ...
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Attribute/dimension adding to the lasfile

.LAS files have different dimensions as x, y, z, etc. Suppose, I want to add another dimension with the name "n". How to do it correctly? I attempted to use the following pdal pipeline: ...
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2 votes
1 answer
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Converting pointcloud data in UTM in txt to LAS

I have text file with point cloud data in UTM format, say sample=[632535.222, 4858488.332, 150.555] I am currently using laspy, the parsing from txt is ready, and I plan to generate a new las file ...
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Projecting LAS to local coordinates using lastools

Is it possible to project LAS files using Open source tools eg. lastools if using a less common coordinatesystem like local swedish espg: 3008 as destination and espg: 3006 as source? I see 3008 is ...
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What is the lidR filter_poi() equivalent to readLAS(..., "-keep_last")?

With the excellent lidR package we can filter at C++ level when using readLAS(), e.g. with the following syntax lidar = readLAS(LASfile, filter="-keep_first") or when the pointcloud is ...
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Point inside the polygon

I'm working in Python with a .las file which I open with laspy and a .shp file which I open with the shapefile library. I have multiple polygons in the shapefile and the task is for each polygon to ...
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Write to a LAS file does not work using lasio

I have a .las file that I am opening using lasio.read('filename.las'). I need to set the negative values for STRT (start depth) to 0, which I can successfully view that I have set it to 0. But when I ...
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2 answers
816 views

Converting LAZ to LAS using laspy

I would like to convert .laz file to .las. I am using Python and I have installed laspy with lazrs extension. I tried in Pyscripter (v4.0) following solution (this solution was mentioned here: Reading ...
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How to get las Zref values after normalization in lidR?

I understand that normalize_height() in lidR creates a Zref attribute so that it can be unnormalized. While I can print Z for the normalized file, I cannot print Zref. Subsequently, when I apply ...
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Output lidR li2012 tree segmentation

I am trying to output the result of li2012 tree segmentation but can't seem to write the new attribute in the original las file or into a new file. This is the code I have: las = readLAS("path/to/...
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filters.assign doesn't work

I want to make all the Z values of the input .LAS file equal to 0. Here is my pipeline: pipeline = [ in, { "type": "filters.assign", "...
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1 vote
1 answer
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How to assign/project las-file using R?

I have got a LAS file from a MLS, which has following specifications: test <- lidR::readLAS("<file.las>") print(test) #> class : LAS (v1.0 format 1) #> memory : ...
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Can I create .las or .laz files from .hgt, .tiff, .gpx/kml or .asc files?

I have got into a golf simulator game and want to recreate my home course. Problem here is that the only import way for height information is a LAZ or LAS file. So I am looking for a way to work ...
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TPI calculation by PDAL [closed]

Is there a convenient way to calculate the topographic position index by PDAL? I have LAS file and what I do is iteratively for every point calculate the TPI. The coordinate information I take from ...
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Identifying coordinate system using ArcMap [duplicate]

I have a .las file made in Agisoft Metashape Pro that is missing a coordinate system. Until I fix this issue, I am unable to reclassify the point cloud. I'm not sure what happened since the DEM and ...
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Efficiently write LiDAR data to CSV with data.table::fwrite

I have a LiDAR file (.las) that I ran through my R function: writelas2csv <- function(x,y) { lasinspatpt <- list(as.spatial(readLAS(x))) write.csv(lasinspatpt, y, row.names = T) } but as we ...
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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/...
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Using lidR to calculate the number of null voxels

I have a number of LAS files (750+). I am using the package lidR to extract different metrics. I am using the following function to calculate the number of voxels in each files that contain a LiDAR ...
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1 vote
1 answer
633 views

Append .las files using laspy

I am attempting to append .las files to another .las file using laspy. Basically, I have a collection of .las files that I need to merge into one large .las file (it's for input into a different ...
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Extract AOI from LAS Dataset into a single las file

I am looking for a way to take a polygon (AOI) and extract a .las file from an las dataset. Currently, when I use the tool Extract LAS, the output is multiple tiles. Is there a way to either a) get ...
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1 vote
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Creating WCS using LAS Dataset

I am looking for a way to serve up an LAS Dataset in order for others to consume it and to analyze it. So far what I've read says that it must be a map, raster/mosiac Dataset, or GDB. Is there a way ...
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LAS Dataset to Raster tool not allowing resolution of window size in Triangulation interpolation to be manually chosen using ArcGIS Pro

I'm working on a workflow to convert a LAS file into a raster to calculate a bare earth model for drone surveys (~300m x 300m with a point density of ~1.5pt/cm^2) using the LAS Dataset to Raster tool. ...
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2 votes
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Big .las to raster converting by writers.gdal

I have a script: pipeline = [ path, { "filename": out_path, "gdaldriver": "GTiff", "resolution": 1, "output_type": "max", ...
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Assigning a CRS to a LAS

Is there a way to assign CRS to the LAS file through Python if the name of CRS is corrupted and looks like following?
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Removing Withheld points from a LAS file with a PDAL pipeline

I'm currently rewriting a system that batch processes lots of LAS/LAZ files. The heavy lifting is in C++/CUDA, but I'm currently working on a preprocessor that downloads the lidar files, finds their ...
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Incorrect CRS affects on writers.gdal result

I have a .las file with CRS that is not decoded correctly and looks like following: At the same time the part of metadata which (as I understand) stands for CRS looks like this: "...
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2 votes
1 answer
204 views

Converting DEM raster (NetCDF file) into point cloud (LAS file) using Python

I would like to convert a DEM raster NetCDF file (*.nc) to point cloud LAS file (LAS/LAZ) using Python language. I have been doing the research but still don't have a result. I also have a look on ...
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How to read LAS header or read only some attributes of LAZ file with LAStools/C++

It takes lots of time when reading laz files when you iterate hundreds of laz file. But reading only the header can only takes less than 100 ms to read hundreds of las files. The same problems arises ...
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How to invert LAS files

I have a bunch of LAS files which are supposed to show data underwater but the depth (z) is poisitive rather than negative so they are inverted. I'm looking for the fastest way to invert/flip them on ...
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Large .las file processing in QGIS

I have a .las file that contains 100.000.000 points (2.6 Gb) and I process it by the custom QGIS plugin based on PDAL and GDAL. The problem is in processing large files as described in the previous ...
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