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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10
votes
3answers
4k 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 ...
19
votes
9answers
4k 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?
2
votes
1answer
45 views

QGIS Print Composer - Display Symbols for Empty Classes?

I am working on a map of mortality rates for several racial/ethnic groups and I have created custom classes to encompass the rates instead of the QGIS classes created through its various modes. This ...
4
votes
1answer
330 views

QGIS 2.4.0 Chugiak 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 ...
3
votes
2answers
164 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 ...
8
votes
3answers
6k 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
1answer
137 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

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 ...
1
vote
1answer
56 views

QGIS Semi-automatic classification plugin install error on OS X 10.10: matplotlib.backends.backend_qt4agg

I have tried repeatedly to install the QGIS Semi-automatic classification plugin via both (1) Plugins > Install & Manage Plugins and (2) manually based on other comments I found here, but I ...
0
votes
1answer
155 views

Masking clouds with Fmask

I have been trying to mask clouds with the quality control band with landsat 8 imagery. The problem I continue to run into is that the quality control bands mistake tops of buildings and concrete as ...
0
votes
1answer
167 views

Problem running i.gensigset in Grass. Any ideas?

It just returns ERROR: Unable to create signature file. It doesn't say why... Anyone had this before and found a solution?