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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626 views

ENVI: Postclassification, remove pixels of certain size

I did a classification over multiple Landsat imagery in ENVI 5.1, which turned out not too bad (ice and snow in Cyan in the picture below). Now I am about to do a postclassification to filter out ...
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1answer
2k views

Google Earth Engine, Supervised Classification

I am trying to perform a supervised image classification to detect water surface area change on two different LANDSAT TM 5 Images, separated by several years. How can I add the numeric property, '...
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1answer
84 views

Labeling Excluded Data of Classification in ArcGIS legend?

I'm symbolizing a feature class by graduated colors classified with 8 classes, but need to symbolize Excluded Data (Nulls for the classified field). However, the excluded data doesn't label, or at ...
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1answer
86 views

When should I run a PCA analysis to classify satelite images?

I want to classify (using training data) some LANDSAT 8 OLI images. I've come across some mentions of PCA analyses to avoid band-to-band correlations. In what cases should one run a PCA? What is the ...
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2answers
704 views

Calculating area of different land uses within boundaries

I am looking to calculate the percentage cover of different land classes in a number of districts in southern Malawi. The land cover map (raster) can be found here - http://www.masdap.mw/layers/...
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2answers
48 views

Converting raster data to have the attached results using ArcGIS Desktop?

I have a huge 30x30m reclassified raster dataset (10 classes) (in the size of Portugal) and I would like to find the easiest way to convert it to kml, having a similar result to the map we bought ...
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1answer
232 views

Evaluating training samples for supervised image classification in ArcGIS Pro?

Its my first time using ArcGIS Pro and I have started doing a supervised classification. In most software you have some tools such as histograms, scatterplots and/or statistics to evaluate training ...
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1answer
179 views

Renaming the value of a proportional symbols layer in Table of Contents in ArcMap

In the case of a - for example - graduated colors or graduated symbols layer, it is easy to rename the value in the Table of Contents. I always click the value name and press F2. However, pressing F2 ...
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1answer
263 views

Reclassify by ASCII ArcMap

How do I create a ASCII remap if I want to reclassify values ranges such as the following: 0 - 200 > 5 201 - 400 > 10 etc.. I have tried it but it gives me this error
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1answer
241 views

How to know the percentage of features that represent a classification in a vector layer

I have a classified vector grid layer with five classes And I want to know what percentage each class represents of the whole vector layer. I'm currently selecting the cells from each class ...
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1answer
1k views

How to count raster pixels inside a vector/polygon layer in QGIS?

I have a binary raster (two classes) and I would like to count the pixels of each class contained in a polygon. My goal is to know the amount of pixels of each class of the raster contained in the ...
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1answer
3k views

Classify satellite Image using Machine Learning [closed]

I am new to the field of Machine Learning and I want to know what all way I can implement machine learning to classify any satellite image.
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1answer
121 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 ...
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1answer
924 views

Remote sensing accuracy assessment - McNemar`s Test

I would like to know how you determine the f12, f21 parameters for use in the McNemar`s test when for example I have two confusion matrices such as below: (where f12 = number of cells misclassified ...
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1answer
440 views

ECD file not produced from the “Train Random Trees Classifier” tool

I am using ArcMap 10.4.1 and i am trying to use the Train Random Trees Classifier tool to create an .ecd file, before finally using the Classify Raster tool to extract certain areas in the raster. I ...
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2answers
565 views

Feature extraction in remote sensing? [closed]

Which are the most common features in order to perform a supervised classification in remote sensing? Furthermore anyone worked with SAR features? Which are the most commonly used? Can anybody ...
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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. ...
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2answers
200 views

LANDSAT 8 Road Extraction

I have 80 LANDSAT 8 Images. I can able to create composite image using Arcgis and then Pansharpen it to produce 15m multi-spectral image as a input for classification process. My requirement is to ...
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1answer
138 views

Performing image classification from Nearmap WMS in ArcGIS Desktop?

I have a subscription to Nearmap that provides me with WMS Server link to their images. I would like to perform image classification using this imagery however I can't work out how to use the WMS feed ...
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1answer
474 views

Classifying LiDAR data to mid vegetation using LAStools?

I want to classify LiDAR vegetation points in low and mid vegetation, using LAStools. High vegetation is simple to get, using top of canopy (first return), but how about low vegetation, and mid? ...
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2answers
4k views

Unsupervised classification with kmeans in R

I have a time series of satellite images (5 bands) and want to classify them by kmeans in R. My script is working fine (loop through my images, convert the images to data.frame, cluster them, and ...
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0answers
214 views

Accuracy assessment in QGIS (Semi-Automatic Classification Plugin) without using random points?

i am using QGIS with the Semi-Automatic Classification Plugin. I already classified a Sentinel 2a scene by using an supervised classification approach. So I have trained areas all over the scene but I ...
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171 views

Extracting specific roads from raster image using ArcGIS Desktop?

I want to create a line shapefiles of white roads from the raster file (screenshot1) using ArcGIS:. My idea is to use ArcScan toolbar, but first of all I need to classify roads pixels values from ...
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0answers
150 views

Delineating coastline with panchromatic imagery

I have a panchromatic satellite image with a large coastline area and my goal is to delineate this coastline with a maximum accuracy and minimum amount of manual work. What is the best option to ...
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1answer
482 views

Using WEKA J48 classifier for satellite image classifications?

I am trying to build a tool from WEKA software using the J48 classifier for automatic satellite image classification to build landuse land cover maps. How do I input the satellite image in WEKA ...
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1answer
44 views

Create average boundary between raster classes

I have a raster with multiple fields in it representing glaciers. As the boundary between land and ice is not often strict, there are little ice fields outside the end of the glacier. I do a raster ...
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2answers
551 views

Nearest Neighbour Classification in eCognition

I have a few papers and youtube videos explaining how to conduct the NN classification in eCognition but it isnt giving me any output. I think the confusion is arising when trying to define the ...
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0answers
211 views

reading .tif and .tif.aux.xml as a whole using geotools

I have sample.tif, sample.tif.aux.xml, sample.qml files in a directory. The .qml and .xml files contain classification data about .tif file. For example my .xml file is something like this: <...
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1answer
1k 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 ...
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4answers
806 views

Automating detection of clearcut areas in optical satellite imagery?

Given optical satellite or aerial imagery of a resolution similar to the image below, is it possible to accurately detect clearcut areas? Is there research or documentation that supports a specific ...
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1answer
845 views

Doing supervised classification on google maps image to show only hedgerows? [closed]

I would like to then use the hedgerows by bringing it into QGIS as a layer. I need to know what software to use and the method to make such a layer? I would like to use a google earth image in Grass ...
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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?
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4answers
2k views

Vector Machine Classification in ArcGIS

Is it possible to perform a vector machine classification of raster image using the ArcGIS software package. This supervised classification method is available in the ENVI software but not for ArcGIS. ...
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1answer
86 views

Performing crop classification without training points (sampling)?

Just theoretical (and maybe very silly) question - Is it possible to do crop classification (supervised or unsupervised) from multi-spectral camera or SAR without direct nexus with training points or ...
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1answer
39 views

Numeric sequence calculation [closed]

My doubt is that I have to do a calculation between 4 rasters. Each raster is classified in 1 to 5. So the final calculation must be a numerical sequence, like: 1111, 1321, 1555, 1432.... for example. ...
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1answer
164 views

Classification validation: Trouble with the Confusion Matrix

I'm supposed to validate my supervised classification with a Confusion Matrix, but I'm having a hard time getting what I should use as a comparison. At first, I used the same ROIs I created for ...
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1answer
106 views

What possible explanations are there for a dramatic change in vegetation appearance in Sentinel 2 data?

I'm looking at land cover in an area of South East Asia. I pulled down Sentinel 2 imagery for Feb 2017, and used the QGIS SCP plugin to complete the land cover analysis, as per this tutorial: https://...
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1answer
651 views

Principal Component Analysis in ENVI

I have a hyperspectral image on which I have performed PCA and now intend on using the output PCA components as an input into a classification. This is the first time I have done PCA, am i correct ...
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0answers
63 views

Endmember selection when applying SAM, SVM and MLC to PCA

I intend to apply the Spectral Angle Mapper (SAM), Maximum Likelihood (MLC) and Support Vector Machine (SVM) algorithms on a hyperspectral dataset in ENVI but I am slightly confused as to how to ...
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0answers
367 views

Using ArcGIS Maximum Likelihood Classification gives Error 010108? [closed]

I am trying to find trees of a single species (Cedar) in my orthophoto. My assumption is that the spectral bands of cedar trees are different to other vegetation (they definitely look different). I ...
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1answer
50 views

Grass projection issue

I am working with GRASS and I am trying to do a supervised classification. The issue here is that I get an error for NaN values. ERROR: Not enough data points Now I know that is an error that you ...
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1answer
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 ...
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2answers
6k views

Land use land cover change post- classification in ArcGIS for cross- tabulation?

I have finished the image classification process in another software package but many papares recommend the ArcGIS package to process post-classification which means from which one land scape type has ...
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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 ...
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1answer
38 views

Is there a way to break up an image file into separate polygons based on colour? [duplicate]

I have a set of land-use maps that I created years ago in ArcMap (see image attached), I need to do more work using them but I have since lost the shapefiles. Is there any way in ArcGIS that I can ...
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3answers
1k views

Defining landuse from remote sensing data? [closed]

I am trying to research ways into obtaining landuse data for a project which calculates the visual impacts of wind parks. I have a DEM and DOPs for a relatively large region (5000km²), but I have no ...
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1answer
766 views

Maximum Likelihood Classification in ENVI

I am a new ENVI user and I am trying to perform a supervised classification of a Landsat 8 image with the maximum likelihood algorithm. In order to run the classification, I have to insert a Scale ...
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2answers
71 views

Select relevant bands from multiband raster?

I try to extract woodland areas from a greyscale orthophoto. I used the "Haralick Texture Extraction" from the Orfeo Tool Box to calculate texture properties of the greyscale orthophoto. As output I ...
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46 views

Automating habitat classification

I’ve been tasked with a habitat classification project which is requiring me to assign thousands of empty polygons different classification types and I do not know how to automate this process. ...
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376 views

Copy class in higher level in eCognition

I use eCognition to do classification. I do segmentation and I class it in level-1. Then I do segmentation in level-2. How to copy class from level-1 and paste the class in level-2 ? There is 'Copy ...