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.

learn more… | top users | synonyms

3
votes
1answer
93 views

How do I classify number values in Python to assign it to a group?

I have calculated the number of points that exists for a SqMi area and am trying now to assign it to a certain group based on where it falls in the classification. Does anyone know a tool that I can ...
1
vote
0answers
19 views

Reclassify based in neighbour polygons

I would like to do a simple operation in QGIS and I am not sure about which is the best option. I have a polygon shapefile and each one has one class attached. I want to reclassify one of them based ...
1
vote
2answers
101 views

Convert a mask image to polygon shape file using GRASS

I used image classification technique in GRASS GIS v7 and generated the image mask below in which white area has NULL value and red area contains 1. I am going to clip those red color areas in a ...
0
votes
0answers
24 views

Semi-Automated Classification Plugin ROI Creation Failure

I can't get the Region-growing to work when running the ROI creation module. What am I missing? Please see the "AttributeError" line halfway down: # An error has occured while executing Python ...
2
votes
1answer
66 views

Correcting Classification for LIDAR - ArcGIS

Is there any procedure to automatically correct lidar classification? My LAS Dataset has water listed as ground and buildings listed as vegetation etc... Just wondering if there is any option to fix ...
1
vote
1answer
72 views

More presentable style class range values, faster

This is as much feature suggestion as it is question: Is there a better way to generate attractive/presentable style class ranges? Currently I have 5 similar datasets. Lets say the values for the ...
0
votes
0answers
61 views

OBIA following connected components segmentation in Monteverdi2

New to Monteverdi2 and OTB. I just finished a connected components segmentation using the Segmentation module and the large-scale vector output mode for large datasets. How can I filter the output ...
3
votes
1answer
130 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 ...
2
votes
0answers
40 views

differentiating stone houses from barren rock in ArcGIS 9.3

I'm working in ArcGIS 9.3 trying to differentiate stone houses (often red brick roofs) from barren rock in a typical Mediterranean karst region via remote sensing. I have been using Landsat imagery. I ...
1
vote
1answer
110 views

How do you remove isolated roads from a bigger network?

I'm trying to perform an OD Cost Matrix calculation on a set of points using a road network from OpenStreetMap data. The network contains lots of roads that don't connect to the rest of the network. ...
0
votes
0answers
18 views

Industries Database - EPRTR?

I am looking for a coherent , complete (At least EU coverage) and reliable (spatial accuracy) databse for INDUSTRIES I have been checking EPRTR database. Basically, it shows around 24,000 industrial ...
0
votes
0answers
34 views

How do you assign classes to percentage data in a data layer?

As a learning project I need to coneptualize a GIS output for assigning classes to data in a raster layer. In this case i have the unemployment rates for relevant magisterial districts in my ...
2
votes
2answers
421 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 ...
0
votes
0answers
43 views

ArcGIS Server Rest API Export with Class Breaks

I'm trying to export a map of a dynamic layer with class breaks. I can export the dynamic layer like this: $mapURL = ...
0
votes
0answers
29 views

Method of extracting the intersecting areas of multiple overlapping polygons (5) and classifying intersects based on spatially joined points

I have concave hulls surrounding clusters of data points which has led me to a lot of overlap and fuzzy boundaries. I am attempting to intersect the overlapping areas but have a minimum of 5 different ...
0
votes
0answers
36 views

classify lines in shapefile by distance to other lines in same shapefile

I'm using ArcGIS 9.3 (and have XTools Pro). I need to classify each line in a shapefile by how close it is to other lines in the shapefile (ie less than 475 ft, less than 450 ft, less than 425 ft) ...
5
votes
1answer
267 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 ...
4
votes
1answer
176 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 ...
0
votes
1answer
87 views

Which Landsat version is appropriate to imply a supervised classification with GRASS GIS?

I need to imply a supervised classification with GRASS GIS to find build-up areas. I want to avoid Landsat 7 images due to SLC problem. Can I use images of Landsat 8 or it's better to use images ...
3
votes
1answer
432 views

How to build a confusion matrix for image classification using SAGA or QGIS?

I did a supervised classification of a Landsat image subset using my training data polygons. I used SAGA GIS for that and everything worked out fine. Now I am stuck since I have no clue how to ...
3
votes
1answer
54 views

Sample classification datasets?

I was looking for some publicly available ground data classification datasets, specifically, locations in e.g. latitude/longitude with a description of the land cover/land use, and a reference e.g. ...
2
votes
0answers
117 views

quantile calculation in qgis

I have a simple question about the graduated classification in qgis (version 2.0.1). I can choose between several statistical methods to classify my data (standard deviation, quantile, natural ...
1
vote
2answers
92 views

how create a specific sub-study area in ArcGIS 10.1 - difficulties with classification

My study area is quite large (sometimes spanning across a few grid squares) and when I am running a viewshed analysis or calculating slope or euclidean distance it calculates for the entire region. ...
1
vote
1answer
70 views

Exporting classnames using Monteverdi

i managed to get my rgb-Image classified with Monteverdi. I discribed 8 classes with different classnames. For my work i dont need the rgb-values, i just need the classnames. Is there any way to ...
2
votes
0answers
168 views

Image classification for a study site falling over two adjacent Landsat 8 scenes (qGIS or ArcGIS)

This question concerns work-flow rather than specific methodological problems. I will be using GRASS to classify Landsat 8 images to create a vegetation map for a study site that happens to fall over ...
2
votes
0answers
82 views

Flood extent extraction from satellite images

How i can extract the floodwater from satellite images? Is the image classification method accurate for moderate-resolution satellite (Terra/Aqua MODIS)? Or is there a more accurate methods? Thanks.
1
vote
0answers
124 views

where to perform principal components analysis and tasseled cap transformation

I want to perform a principal components analysis (pca) and a tasseled cap transformation (tasscap) for a classification.Should i perform pca and tasscap on the original bands of my image or on the ...
1
vote
1answer
136 views

ArcGIS raster data - Group statistics for classification

I'm trying to figure out how to classify a group of rasters. These can't be joined as they have overlaps which must be kept. I was wondering whether there's a way of obtaining grouped statistics - eg ...
1
vote
1answer
116 views

How to do separability analysis in eCognition?

Can I use eCognition to check which bands are more helpful to separate individual classes and to get output result? If so, how can I do this?
2
votes
1answer
1k 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 ...
2
votes
1answer
62 views

From where I can get 4-band satellite imagery of Sweden?

I'm looking for good quality, fine resolution 4-band satellite photos of Sweden for academic use (and I'm willing to pay for it). What I'm after is as detailed as possible photos of certain part of ...
4
votes
1answer
294 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 ...
1
vote
3answers
312 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. ...
3
votes
1answer
291 views

Questions regarding the processing of mosaic Landsat 8

Approximate Translation of Original Question: A question of theoretical and practical about the mosaic of satellite images. I have 3 different months of Landsat images, which need to accomplish the ...
5
votes
2answers
262 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 ...
0
votes
0answers
70 views

How to snap Vector Layer projection to Raster layer projection in QGIS?

I have raster in correct projection. I used ShapeFiles, and marked objects(manually), but i found out that my vector layers have different projection, so they have different size and position. Is ...
8
votes
3answers
4k views

Best source for high-resolution satellite images free/low-cost?

I am doing a household survey in Kenya, and I need to ensure that my survey team visits every house within a given area. I've been going to google maps and right-clicking on roofs to get coordinates ...
5
votes
5answers
1k 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 ...
0
votes
1answer
143 views

How do I classify or spot a pixel, based on a specific reflectance values of the six Landsat Bands using Erdas?

I have converted the DN values to the reflectance of a Landsat image to classify the rice field by its stages. To specify the reflectance values of each stages, I have sampled the reflectance values ...
5
votes
1answer
127 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 ...
2
votes
1answer
1k 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 ...
2
votes
0answers
422 views

ISODATA unsupervised classification in ArcMap 10.1

I’m doing a project on landsat 5 images. I’ve composited the images into 1 raster, and I want to classify the raster with ISODATA Unsupervised Classification. How do I calculate the best number of ...
7
votes
2answers
126 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, ...
6
votes
3answers
184 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 ...
2
votes
2answers
1k views

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

Please some one help me first I have finished the image classification process in another software package but many literary recommend Arc GIS package to process post-classification which means from ...
6
votes
3answers
301 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 ...
0
votes
2answers
79 views

Common class range for different attributes in a same polygon shapefile

I have a polygon shapefile which has population attributes pop90,pop91 and so on for 10 years. They have different minimum and maximum value for each of the years. Now I need to do classification for ...
6
votes
1answer
672 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 ...
3
votes
0answers
381 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 ...
1
vote
0answers
118 views

Segmentation Violation in ArcView 3.1 while performing UpdateLegend?

I am loading a ".avl" legend file into ArcView 3.1 and I am plagued with a recurring Segmentation Violation Error when I execute the updatelegend command in the theme. It looks like the legend file ...