Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

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?
16
votes
5answers
6k views

Freeware alternatives to eCognition? [closed]

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, ...
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 ...
13
votes
3answers
3k 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. ...
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 ...
12
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
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, ...
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, ...
10
votes
6answers
2k 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?
10
votes
3answers
1k 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 ...
9
votes
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 ...
9
votes
1answer
8k 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 ...
8
votes
2answers
5k 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?
8
votes
3answers
2k 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: ...
8
votes
1answer
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 ...
8
votes
1answer
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 ...
7
votes
5answers
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 ...
7
votes
4answers
786 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 ...
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?
7
votes
2answers
155 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....
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-...
7
votes
3answers
827 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 ...
7
votes
1answer
126 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 ...
7
votes
1answer
225 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 ...
6
votes
2answers
710 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 ...
6
votes
2answers
2k 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.
6
votes
1answer
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 ...
6
votes
1answer
5k 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 ...
6
votes
3answers
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 ...
6
votes
2answers
1k 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 ...
6
votes
3answers
210 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 ...
6
votes
1answer
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 ...
6
votes
3answers
171 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 ...
6
votes
1answer
5k 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 ...
6
votes
1answer
157 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, ...
6
votes
1answer
297 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 ...
6
votes
0answers
697 views

Land Classification with Spectral Python (SPy) [closed]

Does anyone have experience working with the Spectral Python module for land classification? The following k-means clustering example takes an iterative approach to classification through pixel ...
5
votes
3answers
3k views

Pixel-based and object-based classification!

I would like to understand if pixel-based classification algorithm (e.g. Maximum Likelihood classification ) can be used for object-based classification (i.e. after a segmentation procedure). On the ...
5
votes
2answers
8k views

Reclass for vector data in ArcGIS Desktop?

I've got a vector dataset (in fact, OS MasterMap data) and I want to set the value of a certain field based on the value of another field. For example: Field1 Field2 Building 20 Grass ...
5
votes
2answers
566 views

Can LiDAR differentiate between rock and soil?

Can LIDAR by itself, tell the difference between rock (large and small) and soil? I'm under the assumption that the answer is no. However, I wanted to check here with the experts as I was told by ...
5
votes
2answers
349 views

Random Forest to estimate land use in past with Landsat

I am new in Machine Learning and in R. I am working in my Master thesis. I am trying to estimate the LULC of the years 1984, 1990, 2000, 2011, 2014 for characterizing the forest dynamics. I have for ...
5
votes
1answer
133 views

QGIS Gratuated Symbology gives differents results on every classification with Natural Breaks (Jenks)

When styling a polygon layer using the Graduated styling and the Natural Breaks (Jenks) mode, QGIS is classifying the data with different values. So every time I click on "Classify" the values are ...
5
votes
1answer
1k 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.
5
votes
1answer
6k views

the difference between pattern recognition and image classification in remote sensing? [closed]

Does anyone know the difference between pattern recognition and image classification?
5
votes
2answers
891 views

LANDSAT Image classification and open source solution(s)

I have some experience with ERDAS IMAGINE in doing some supervised/unsupervised LANDSAT imagery classifications and now find myself in the position of needing to do the same but without the access to ...
5
votes
2answers
1k 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?
5
votes
1answer
221 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 ...
5
votes
1answer
3k 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 ...
5
votes
2answers
596 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
786 views

LiDAR dataset which is benchmarking for testing classification algorithms?

Is there a publicly available benchmarking database of classified (labeled) LiDAR data? For example, where each point is classified as ground, vegetation, building, road, water, etc? The point clouds ...