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.

Filter by
Sorted by
Tagged with
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?
user avatar
  • 82.1k
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 ...
user avatar
  • 727
16 votes
6 answers
8k views

Freeware alternatives to eCognition?

Does anyone know any good freeware alternatives to eCognition? I need to do image segmentation and classification. I tryed the ecognition trial and it was really good. I'm doing the job with SPRING, ...
user avatar
  • 5,298
15 votes
3 answers
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 ...
user avatar
  • 34.6k
15 votes
3 answers
9k views

Distinction between pixel-based and object based classification?

I am struggling to clearly understand the distinction between pixel-based and object-based classification in the remote sensing domain and am hoping someone from this community can provide insight. ...
user avatar
  • 153
14 votes
5 answers
8k 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 ...
user avatar
12 votes
3 answers
2k views

Handling mountain shadows when classifying Landsat 8

I'm trying to classify some area in northern Mongolia using Landsat 8 satellite images from 2013. Since the recordings were made in winter, the sun is very low at the acquisition time. Therefore there ...
user avatar
  • 302
11 votes
1 answer
13k 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 ...
user avatar
  • 111
10 votes
4 answers
10k 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, ...
user avatar
  • 101
10 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, ...
user avatar
  • 3,266
10 votes
6 answers
3k views

What is this "brown spot" in Google maps?

I was in Google maps today and noticed near Baltimore, US where the river is, there's a huge brown spot. Is this due to all of the waste? If so, will this keep going all the way into the ocean?
user avatar
  • 201
10 votes
1 answer
3k 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 ...
user avatar
  • 1,076
10 votes
2 answers
5k 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 ...
user avatar
  • 874
10 votes
0 answers
1k views

What is the convergence threshold for ArcGIS Iso Cluster?

The ArcGIS tool Iso Cluster Unsupervised Classification does not seem to have any documentation on the convergence threshold used in the tool. To compare, Erdas Imagine has all of the necessary ...
user avatar
  • 50.3k
9 votes
2 answers
8k 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 ...
user avatar
  • 464
9 votes
3 answers
8k 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?
user avatar
8 votes
2 answers
7k views

what's the difference between spectral signature and features in remote sensing?

I would like to understand if is there any difference or relation between spectral signature concept and features in remote sensing?
user avatar
  • 305
8 votes
4 answers
1k 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 ...
user avatar
  • 10.6k
8 votes
1 answer
8k views

SAR - Using the Intensity or the Amplitude for the classification

In a Sentinel-1 Level 1 Ground Range Detected SAR data product, Intensity = Amplitude * Amplitude. Should the intensity image or the amplitude image be used for radiometric calibration when using ...
user avatar
  • 946
8 votes
3 answers
3k views

How to easily identify/classify coniferous forest from one date Landsat image?

I am pretty new in remote sensing and I am trying to identify/classify coniferous forest cover from single date Landsat scene. According to my preliminary web research I have these possibilities: ...
user avatar
  • 3,266
8 votes
2 answers
3k views

Unsupervised raster classification using GDAL

Is there an equivalent in GDAL to the Arcpy ISO data unsupervised classification tool, or a series of methods using GDAL/python that can accomplish this?
user avatar
  • 742
8 votes
2 answers
5k 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 ...
user avatar
8 votes
1 answer
6k views

Unsupervised classification in QGIS

I was trying to learn unsupervised classification in QGIS 2.6 following the tutorial video: https://www.youtube.com/watch?v=mI80eENtWSE When trying myself, clicked Run during the process it shows the ...
user avatar
  • 571
8 votes
1 answer
2k views

Open software tool or QGIS plug-in to make land cover classification

Is there any tool or plugin for QGIS/GRASS to make an automatic land cover classification from satellite imagery --- based on CLC nomenclature for example? Of course, it will not be 100% sure but it ...
user avatar
  • 8,502
8 votes
1 answer
320 views

Getting different "Layer Errors" every time for the same code in GEE

I am running a classification code and getting different errors every time. classification: Layer error: The service is currently unavailable. classification: Layer error: Computation timed out. ...
user avatar
  • 127
8 votes
1 answer
2k views

How to perform unsupervised classification of LANDSAT time series using Grass?

I'm using GRASS to perform an unsupervised classification on a time series of LANDSAT images (monthly temporal res, over 30 years), in order to compare land cover change in a particular area. I'm ...
user avatar
  • 320
7 votes
5 answers
3k views

Which methods are most suited to classifying urban areas from Landsat imagery?

I am trying to use Landsat data to map urban extents over time. I need to perform a classification into built up / non built up areas. I am new to image classification. I have access to the following ...
user avatar
  • 239
7 votes
2 answers
8k 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.
user avatar
  • 219
7 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.
user avatar
7 votes
2 answers
149 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 ...
user avatar
  • 103
7 votes
2 answers
5k 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 ...
user avatar
  • 1,739
7 votes
3 answers
2k views

How to generalize training data for a random forest classifier?

I am working with a random forest classifier in eCognition (new with eCognition 9.0). The image shows 8 NAIP tiles I am attempting to classify using approximately 100 training points. The training ...
user avatar
  • 50.3k
7 votes
2 answers
2k views

How to know what spectrum image layers are in eCognition?

I'm learning to use eCognition (8.1) and my teacher has provided me with some example tif files to segment and classify. The tif files have multiple layers, each of which are supposed to represent a ...
user avatar
7 votes
2 answers
166 views

How to classify agriculture employment data?

I have employment data which are huge - about 500 data for each category, like agriculture field, fishing field etc. Now I want to categorise this data in to 7 ranges. Suppose <50=1, >50-100=2, etc....
user avatar
  • 79
7 votes
1 answer
3k 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-...
user avatar
7 votes
3 answers
1k views

Identifying training sites?

Prior to image classification, collection of training sites and obtaining a signature file is the most critical step. Field visits with a reliable GPS Unit is usually the first step followed by ...
user avatar
  • 4,579
7 votes
1 answer
554 views

How can I get a numerical (or value) display for equal intervals in a layer?

I'm looking to classify regions on a map by the amount of light pollution in the area. I have the varied intensities (0 through 60) plotted using a color map, but is there anyway that instead of a ...
user avatar
  • 81
7 votes
1 answer
235 views

View data of a particular year in Google Earth

For my region in India, Google Earth tiles belong to different years, 2003 - 2010. I don't mean GE's historical view feature but the imagery updates for different areas my region. I classify Landsat ...
user avatar
  • 4,579
7 votes
1 answer
2k 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 ...
user avatar
6 votes
2 answers
1k views

What is the theory behind graduated symbols in QGIS?

QGIS offers 5 methods of classifying vector map data (quantiles, equal interval, etc). What is the theoretical base of these methods? If there are certain methods suitable for certain types of data or ...
user avatar
6 votes
2 answers
8k 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. ...
user avatar
6 votes
2 answers
947 views

Can you store a Classifier in Google Earth Engine for later use?

Training a classifier in Google Earth Engine is slow and can sometimes show temporary errors like "Capacity exceeded". To combat this, I would like to train the classifier, store it, and ...
user avatar
6 votes
1 answer
2k views

Random Forest land cover classification in ArcMap?

I am an undergraduate student working with a very large data set (to me), and who has NO experience with R, but is fairly comfortable with ArcMap. I have about 60GB of 8band 1m satellite imagery of ...
user avatar
  • 61
6 votes
3 answers
451 views

Landsat 8 striping/banding citation

Does anyone have or know a citation for the Landsat 8 striping that affects some scenes (Brazil shown here). It's apparent in all bands (B3 here at 100% stretch) and is present in both RAW and ...
user avatar
6 votes
1 answer
505 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 ...
user avatar
  • 73
6 votes
1 answer
1k views

ArcMap Natural Breaks Classification

I realize that ESRI is calling their implementation of Fisher-Jenks proprietary. Given the performance with mid-sized datasets, either a significant optimization or a sampling method are being ...
user avatar
  • 4,349
6 votes
3 answers
217 views

Classifying small structure in water using IR band

I was wondering how to identify small structures (eg. beacons) in a water body? I have worked with RGB images and its almost impossible to classify waterbodies in these images. How does the IR band ...
user avatar
  • 669
6 votes
1 answer
5k views

How do I manually classify graduated data in QGIS?

Is there any way to manually classify Graduated Data in Qgis. In ArcGIS I always used to apply first the natural breaks method to find adequate group sizes for good visual interpretation. Afterwards I ...
user avatar
  • 319
6 votes
1 answer
450 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 ...
user avatar
  • 10.4k
6 votes
1 answer
175 views

Landsat ML classification: Apply accuracy measures to scenes without reference data?

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, ...
user avatar
  • 3,266

1
2 3 4 5
14