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Questions tagged [classification]

The process of sorting or arranging entities into groups or categories; on a map, the process of representing members of a group by the same symbol, usually defined in a legend.

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11 votes
4 answers
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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
15 votes
3 answers
9k views

Land Cover Feature Extraction from Satellite Imagery

I'm interested in a low-cost or open source solution for creating land cover GIS layers that utilize both spectral and textural extraction algorithms. I have used PCI Geomatica, ENVI, and Feature ...
artwork21's user avatar
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15 votes
5 answers
9k views

Extracting tree crown areas from remote sensing data (visual images and LiDAR)

I am looking for a method to process a remote sensing image and extract the crown areas of the individual trees from the image. I have both visual wavelength areal imagery, and lidar data from the ...
Theodore Jones's user avatar
15 votes
2 answers
12k views

Moving from Earth Engine image to array for use in sklearn

I've produced a very large multiband image in EE with the goal of classifying it using the classifiers implemented in sklearn (the native ones implemented in EE don't provide enough flexibility for my ...
LAT's user avatar
  • 559
7 votes
2 answers
10k views

Reclassifying raster layer with certain colors for value ranges in QGIS?

I'm using QGIS. I want a raster layer with 6 different colors each color representing a certain value range (e.g. -1 to 0 red, 0 to 0.2 orange). In the layer style menu I can only approximate colors.
dadadingo's user avatar
  • 229
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
18 votes
9 answers
7k views

Which Tools do you use for Classification of Remote Sensing Data?

Which tool do you prefer to use for classification of remote sensing data, e.g. classifying land use, and why? Which other tools have you tried, and why did you decide against them?
underdark's user avatar
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9 votes
3 answers
10k views

Classifying LiDAR data with LAStools?

I am presently using LAStools to analyse LiDAR data. Can LAStools classify the points into various features such as vegetation, roads, buildings etc? If so, how is it done?
Purity Rima's user avatar
8 votes
1 answer
3k views

Is it possible to set different scale dependent visibility for one layer classifications?

I'm working on a sewer and water network, so I need to set different scale visibility for primary, secondary and tertiary network.
Kevin Malone's user avatar
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
5 votes
2 answers
2k views

Cleaning LiDAR points that classification algorithm misses?

There are numerous methods for classifying ground and not-ground points from raw LAS point clouds. They all do a great job, depending on local circumstances, but inevitably even when algorithm and ...
matt wilkie's user avatar
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4 votes
1 answer
299 views

Setting GroundFilter parameters for low density point clouds?

I'd like to use the function GroundFilter on my dataset. However, the manual says that the default values of the parameters used by this function (g parameter, w parameter) are related to a high ...
Melissa Latella's user avatar
4 votes
1 answer
2k views

Performing Random-Forest Classification of 10cm Imagery for species-distribution in R (no point-shapes)? [closed]

I'm trying to classify 10cm-resolution images with the RF-package. I do this to separate some species in the forest, seen on my images. While I was searching for an answer, I found the following ...
steveomb's user avatar
  • 147
3 votes
1 answer
382 views

QGIS Print Composer - Display Symbols for Empty Classes?

I am working on a map of mortality rates for several racial/ethnic groups and I have created custom classes to encompass the rates instead of the QGIS classes created through its various modes. This ...
pophealth's user avatar
2 votes
1 answer
694 views

Empty signature file after i.gensig in GRASS

I'm trying to make a supervised classification in Grass 6.4.3 under Linuxmint 16. After digitizing the training areas, I transformed them from vector to raster. Then I've done the following: just in ...
Lucas's user avatar
  • 193
2 votes
2 answers
4k 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
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
1 vote
1 answer
5k views

memoryerror in Supervised Random Forest Classification in Python sklearn

I have Landsat 8 preprocessed image I want to classify using random forest(RF) classification in python. The size of the image is 3,721,804 pixels with 7 bands. I have 250 training data shapefiles ...
Kaleab Woldemariam's user avatar
0 votes
1 answer
84 views

Is there a way to classify simple non-spectral images in ArcGIS?

I was wondering whether there's a way to classify simple non-spectral TIFF images in ArcGIS (maybe based on similar colour values of image pixels like graphic software applications such as Photoshop ...
M_S's user avatar
  • 353
18 votes
1 answer
8k views

Using Orfeo Toolbox object based classification in QGIS tutorial/workflow?

I have a set of aerial photos of vegetation which needs to be classified. Instead of using manual interpretation, I want to try using Object-Based classification based on the Orfeo Toolbox in QGIS ...
monruw's user avatar
  • 757
12 votes
1 answer
5k views

What is the difference between sample, sampleRegions, and stratifiedSample in Google Earth Engine?

According to the documentation of GEE ee.Image.sample() samples the pixels of an image and returns them as a FeatureCollection, in which each feature has 1 property per band in the input image. You ...
Michael's user avatar
  • 1,186
11 votes
1 answer
16k views

Convert 32 bit image to 8 bit image in QGIS

I want to convert my images from 32 bits to 8 bits. I'm using otb to calculate texture and the raster output is on 8 bits, I'm going to use this information as a layer stack for my multispectral image ...
user21484's user avatar
  • 111
9 votes
2 answers
2k views

Methodology for Hansen classification of Global Forest Watch?

I have just discovered amazing Hansen´s classification about forest loss and re-growth, available at http://www.globalforestwatch.org/, published in Science, 2013 as: Hansen, M. C., Potapov, P. V, ...
maycca's user avatar
  • 3,376
8 votes
2 answers
7k views

Changing line width by classification in QGIS

I am using QGIS 2.18.18 I have a map of rivers and I want to style them based on their width. I have width as an attribute of the rivers layer. Just as we can style colors by category or graduated ...
Dhaval Shukla's user avatar
7 votes
2 answers
6k views

Stratified random sampling with Google Earth Engine Error

I am trying to sample points from a classified raster using Google Earth Engine, but am running into some problems. I developed a script based on the Classification video located here. Here is a toy ...
user44796's user avatar
  • 1,925
7 votes
1 answer
3k views

Results of Variable Importance of RF Classifier in GEE

I create a RF module in GEE like this: //Random Forest Result Function Module exports.getRfResults = function(image, title, bands, trainPoint, testPoint, area, label) { //Create Sample Points ...
BerkayOzen's user avatar
7 votes
2 answers
397 views

Classifying raster layer by number of equal values in given area using QGIS

I am using QGIS 3.16.12 - Hannover. I have a binary raster layer which consists of 2 values, either 0 or 1 (in my screenshots, 0 = black, 1 = white). The 1 values are scattered throughout the layer in ...
Snowy's user avatar
  • 113
6 votes
2 answers
11k views

Conversion from Raster to Vector in Google Earth Engine?

I have applied unsupervised classification on an image in Google Earth Engine using k means clustering algorithm. I have made 15 classes and I have visualized those 15 classes by adding a map layer. ...
Rawail Naeem's user avatar
6 votes
1 answer
4k views

How to Remove Topographic Effects Like Shadows from Landsat Image

I am using QGIS 2.4.0 Chugiak on my windows 8.1, for classification of landsat 5-7 image that contains hilly mountains with dense forest and 60% area are plains. I am classifying through Semi-...
Waseem Ali's user avatar
6 votes
1 answer
503 views

How to design class breaks for a time series of choropleth maps?

I'm working with a time series of choropleth maps showing the same indicator for the same administrative boundaries, but spanning period of nine years. What would be the most appropriate strategy of ...
radek's user avatar
  • 10.6k
5 votes
1 answer
335 views

Classifying different surfaces having almost similar Reflectance responses

I am using ENVI 5.3 to classify a Region of Interest clipped from Landsat 8 OLI. I have already performed calibration of my DNs by transforming it into Radiance and derived Reflectance image using ...
Dave's user avatar
  • 1,208
5 votes
4 answers
2k views

QGIS classifying vector data

I am trying to classify a shapefile based on rule set, following this tutorial. This is the result: What I want to ask is: 1. How to insert the classification result (water, land etc) into the ...
monruw's user avatar
  • 757
5 votes
4 answers
2k views

Performing supervised classification on Sentinel images

I'm looking for python code which predicts the LULC of my data(other raster files apart from refernce data band1, band2 and soon) using svm classifier with rbf kernel based on reference data (truth ...
hashalluring's user avatar
4 votes
1 answer
5k views

Image classification random forest [duplicate]

I am a newbie in R. I want to classify images using random forest in R. I am trying to learn the codes. But in the mean time, is there a push button (like a gui) in R that can be used for ...
abantika's user avatar
4 votes
2 answers
226 views

Giving polygons classificaton code in ArcGIS Desktop?

Does anyone have a trick for assigning polygons a code based on the classification classes? For example, if I symbolize the population of census blocks with 10 classes using Natural Breaks, I would ...
Mercator's user avatar
  • 283
3 votes
1 answer
525 views

Correcting class codes of LiDAR files in ArcGIS

Is there any procedure to automatically correct lidar classification? My LAS Dataset has water listed as ground and buildings listed as vegetation. Just wondering if there is any option to fix this.
rspencer38's user avatar
3 votes
2 answers
724 views

Spatial Classification

I am not sure what to call my problem. From this image, I have a set of classified polygons (colored). I would like a way to classify the white polygons in the image. I don’t have any attributes to ...
dharv's user avatar
  • 41
3 votes
1 answer
2k views

Black Exported TIFF file Google Earth Engine?

I am trying to export the TIFF file from Google Earth Engine, but the exported file appears black. var image = ee.Image(ee.ImageCollection("COPERNICUS/S2") .filterBounds(roi) ....
Filippos Eliades's user avatar
3 votes
1 answer
1k views

Styling line layer based on discrete and continuous attributes in QGIS

I have found a really helpful tutorial to style points based on two attributes. Is it possible to make style lines based on two attributes? I have a shapefile with streets that have two attributes: ...
Lorenzo Beltrami's user avatar
3 votes
1 answer
303 views

Is there a function in PyQGIS (QGIS 3.10) similar to the ''slice" function in ArcPy?

I am working on a script that automatically generates heatmaps from point data. I am aware of the heatmap/KDE tool already existing in PyQGIS (I am working in QGIS 3.10). What I want to do after ...
Bram's user avatar
  • 43
3 votes
3 answers
152 views

Apply accuracy measures from partial area to the whole classified maps?

I applied supervised maximum likelihood classification to a yearly stack of Landsat images (resolution 30m). The land cover classes are related to coniferous forest, i.e., forest, clear-cut, fire, ...
maycca's user avatar
  • 3,376
3 votes
3 answers
2k views

Determining if polygon lies completly in another polygon or only partly using QGIS? [closed]

I primarily use QGIS. I have two Layers which both contain polygons.So one layer(A) contains only one polygon, the other contains a number of polygons(layer (B)). I can run the Intersect-Tool and ...
UrsP's user avatar
  • 39
3 votes
3 answers
196 views

Is it scientifically valid to compare landcover/use generated from different types of spatial resolution products

This question is mainly for the validity of the comparison of the classification product of different types of spatial resolution. Is it scientifically valid to compare very high-resolution image ...
Learner's user avatar
  • 3,496
3 votes
1 answer
735 views

Split polygons in a shapefile based on distance [closed]

I have polygons as shapefile sprawl on very large area in Brazil, with many "blank" area in the middle: I would like to split this shapefile to smaller groups of polygons based on their ...
ReutKeller's user avatar
  • 2,149
2 votes
1 answer
180 views

Sudden increase in the download size of images from GEE

I am working on LandSat 8 data to build a classifier for built up and non built up areas in a particular district. I was using the following code for classification and then to export my classified ...
scottstots's user avatar
2 votes
2 answers
2k views

Classifying data as Natural Breaks using ArcPy?

Is there any chance I can create a simple python script to classify my data as Natural Breaks? I have only created a script for quantile classification, but it is not enough for my work. arrp = ...
user77135's user avatar
2 votes
1 answer
213 views

Surface reflectance product - do I always need it?

There is a neat Surface Reflectance product of Landsat imagery. I know the difference between SR and raw products: SR presents calculated values, that are supposed to represent state of the Earth ...
adamczi's user avatar
  • 739
2 votes
1 answer
2k views

Mask out pixels smaller than 1ha in Google Earth Engine

I am new here so please forgive any mistakes in this post: I have a simple script to classify cultivated area vs none cultivated areas using Sentinel-2 in GEE. I want to mask out all objects that are ...
Sibonile's user avatar
2 votes
2 answers
689 views

Interpolating LiDAR scattered ground data?

I wonder if someone can give me a hint on how to interpolate sparse data. I have a 1km by 1km tile located in a dense rain forest area. Original LiDAR data are 37,395,021 points. I have played with ...
Gerardo Jimenez's user avatar
1 vote
1 answer
987 views

Remove cell boundaries of raster pixels converted to vector format

I have a solar radiation shapefile with 10 km x 10 km cells. When I put it on QGIS, many pixels with boundaries take place. Please see the following image: How can I remove them in Qgis?
Saulo Carvalho's user avatar