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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4answers
6k 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, ...
14
votes
3answers
8k 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 ...
12
votes
5answers
5k 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 ...
6
votes
2answers
3k 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.
7
votes
3answers
6k 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?
4
votes
2answers
933 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 ...
3
votes
1answer
918 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 ...
18
votes
9answers
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?
4
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1answer
1k 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 ...
4
votes
1answer
139 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 ...
3
votes
2answers
908 views

Manually editing a LiDAR cloud to remove non ground points

I've recently been tasked with cleaning up a LiDAR file of a river where I need to remove trees, shrubs and power lines that run right across the river. I was looking into LAStools but it has a limit ...
2
votes
2answers
3k 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. ...
2
votes
1answer
513 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 ...
2
votes
1answer
219 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 ...
0
votes
1answer
49 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 ...
13
votes
1answer
5k 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 ...
10
votes
2answers
1k 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, ...
9
votes
1answer
9k 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 ...
7
votes
1answer
2k 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-...
4
votes
4answers
972 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 ...
4
votes
1answer
4k 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 ...
3
votes
2answers
528 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 ...
6
votes
1answer
305 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 ...
5
votes
2answers
568 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 ...
5
votes
2answers
764 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 ...
5
votes
1answer
232 views

How to classify 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 ...
2
votes
1answer
120 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 ...
2
votes
2answers
1k views

Classification to attribute

Using Esri Desktop Advanced 10.2.2 is it possible to create an attribute based on a classification method, i.e. Jenks? To elaborate - if you use the symbology tab in a layers properties, you can set ...
2
votes
2answers
213 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 ...
1
vote
4answers
1k 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 ...
0
votes
1answer
1k 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 ...
4
votes
2answers
132 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 ...
3
votes
3answers
112 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, ...
3
votes
1answer
100 views

What's 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 ...
3
votes
1answer
433 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.
3
votes
2answers
2k 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. ...
1
vote
1answer
1k views

QGIS Semi-automatic classification plugin install error on OS X 10.10: matplotlib.backends.backend_qt4agg

I have tried repeatedly to install the QGIS Semi-automatic classification plugin via both (1) Plugins > Install & Manage Plugins and (2) manually based on other comments I found here, but I can'...
1
vote
1answer
357 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?
1
vote
1answer
164 views

Batch processing multiple files with MCC-LIDAR?

I want to classify ground points from multiple LiDAR tiles (.las files) using MCC-LIDAR software. I already made some research and I have found this sourceforge thread; however, it is not that clear (...
1
vote
1answer
939 views

How to use thematic layer for supervised classification in eCognition

I'm classifying vegetation in eCognition. From ArcMap I already have a shapefile with training polygons that I would like to use for this but so far I was only able to insert this as a thematic layer ...
0
votes
1answer
121 views

Compare Multiple attributes visually

I am working on a project in which I want to take point features( tweets) and compare them to the GDP per capita of countries. I would like to have my end result be such as the following: GDP Class 1 ...
0
votes
1answer
223 views

Problem running i.gensigset in Grass. Any ideas?

It just returns ERROR: Unable to create signature file. It doesn't say why... Anyone had this before and found a solution?
0
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1answer
1k views

Classifying slope (flat, slope, steep, very steep) in QGIS? [duplicate]

I want to classify the slope of the DEM data, by dividing the slope by 4 classes: flat, ramps, steep, very steep. How to do this with QGIS?
0
votes
1answer
242 views

How can ee.Image.stratifiedSample() be used in Google Earth Engine to select training samples for a binary classifier?

This is a follow-on question to How can one create a binary image from a FeatureCollection in Google Earth Engine? The corresponding minimal example can be found here: https://code.earthengine.google....
0
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0answers
216 views

How to export training area information?

I did a supervised classification of a whole Landsat 8 image with 700 Rois (training areas) with the Semi Automatic Classification Plugin. I want to export the class names, the coordinates and the ...
0
votes
1answer
124 views

Plot areas by class in a polygon with Google Earth Engine

I would like to plot the number of pixels or the area for each class contained in a polygon (shape of a country). I have found the ui.Chart.image.byClass function but I don't understand how to use it ...
0
votes
2answers
1k views

Area calculation of mapped categories in ArcGIS Desktop?

I have performed supervised classification (Interactive supervised classification and Maximum Likelihood Classification) on landsat reflectance raster data to classify it into seven land use ...