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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13
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6answers
3k 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, ...
12
votes
3answers
5k 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 ...
10
votes
6answers
1k 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
1answer
3k views

Permanently Change ArcMap's “Maximum Sample Size” Setting?

I've lately been working on feature classes with a huge number of polygons (e.g. all of the Census blocks within the Chicago metro area). I've been needing to symbolize them by quantities a fair ...
9
votes
2answers
573 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, ...
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
3answers
568 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 ...
7
votes
2answers
1k 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?
7
votes
3answers
752 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: ...
7
votes
2answers
142 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, ...
7
votes
3answers
211 views

Best practices for 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
1k 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
1answer
201 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
319 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
3answers
430 views

Is it possible to automate the 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 their research or documentation that supports a specific ...
6
votes
3answers
604 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
3answers
199 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 IR band help ...
6
votes
1answer
203 views

Orfeo Toolbox object based classification in QGIS tutorial/workflow

I have a set aerial photos of vegetation which need to be classified. Instead of using manual interpretation, I want to try using Object-Based classification based on the Orfeo Toolbox in QGIS ...
6
votes
0answers
533 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
5answers
2k 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 ...
5
votes
2answers
5k 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
146 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
1answer
777 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 ...
5
votes
2answers
261 views

How to change class break schemes in QGIS to eliminate overlap

When using Graduated Symbology in QGIS, by default the bounds seem to be overlapping. For example, class 1 shows 0-100.000; class 2 shows 100.000-200.000; class 3 shows 200.000-300.000 where it ...
5
votes
1answer
696 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 ...
5
votes
1answer
78 views

Aggregating polygons with space between them

Im currently editing a large dataset that has large chunks removed throughout (buffered road network). The areas adjacent from each side have coinciding attributes, but have this large erased area in ...
5
votes
1answer
373 views

Identify shadow on Landsat image by Hillshade Tool (spatial analysis) in ArcGIS?

I would like to automaticaly identify shadows on Landsat scene in mountaineus area using Hillshade Tool (ArcGIS 10.1). I have 1 Landsat image from one date DEM (SRTM) from the same area To create ...
5
votes
2answers
564 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 ...
5
votes
1answer
773 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 ...
5
votes
1answer
97 views

Is it possible, and if so how, to effectively classify vegetation types using false near infra red imagery?

Background : I use near infra-red imagery to delineate wetlands and water bodies with good success. It's also obvious to distinguish between new healthy vegetation and older growth and land areas with ...
5
votes
1answer
198 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 ...
4
votes
5answers
2k 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 ...
4
votes
3answers
1k 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 ...
4
votes
4answers
125 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
3answers
837 views

Remote sensing: How to define landuse from remote sensing data?

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 ...
4
votes
2answers
119 views

Double classification for symbols in QGIS

I am using QGIS version 2.14.1 (Essen). I have symbols that I have classified according to certain value from one of the columns in my shapefile. Furthermore, I was wondering if it is possible to do ...
4
votes
2answers
167 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 ...
4
votes
1answer
229 views

What does Error 000885: Input Signature file does not have file extension indicate?

I can't run a Maximum Likelihood Classification because an Error 000885 says my input signature file does not have a file extension but it actually does as you can see in the picture. What am I ...
4
votes
1answer
2k views

How to train a signature file for supervised classification in ArcGIS 9.3

I wanna do supervised classification in ArcGIS 9.3. I have a 321RGB composite of a pretty good quality which I want to use for supervised classification. How can I create signature file which contains ...
4
votes
1answer
3k 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 ...
4
votes
1answer
323 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 ...
4
votes
1answer
3k 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 ...
4
votes
1answer
730 views

Standard Terminology for User's and Producer's Accuracy

In the literature I see terms such as, User's accuracy Pr( Y = c | X = c); Producer's accuracy Pr( X = c | Y = c); where X is the estimator of a particular land use, Y is the random variable ...
4
votes
1answer
601 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 ...
4
votes
1answer
850 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 ...
4
votes
1answer
423 views

Is there another way to acces the histogram in ArcGis 10

i need the histogram of the frequency to heights distribution like in the attached picture. Is there another toolkit to access this data? A screenshot is not suitable :) The attribute table is not ...
4
votes
1answer
470 views

Creating management zones in NDVI ortho maps with contour like lines

This question is hard to explain so if you have a possible answer I would love to hear it. I work in the precision agriculture business which heavily relies on NDVI calculations but need to create ...
4
votes
0answers
25 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 ...
3
votes
1answer
2k views

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

Does anyone know the difference between pattern recognition and image classification?
3
votes
1answer
514 views

Differentiating Cloud and Snow in unsupervised classification of mountaneous terrain?

I am doing unsupervised classification of a mountaneous terrain and I have used 500 classes to classify the land use. In my result, cloud and the snow are categorized in the same class. How do I ...