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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3
votes
2answers
60 views

Classifying raw LAS data as bare earth in ArcGIS for Desktop?

I have a raw LAS data that has only one return (no second/ third.. return) and not classified yet. The only information I have is intensity and elevation. Is there any way that I can classify bare ...
2
votes
2answers
34 views

Is it Possible to Resize the Pixels

I classified this image in ArcGIS 10.3, but my Professor said the pixels are big and I should make it smaller. This is my problem: is there any tool that can use to make the picture grains finer. Or ...
1
vote
1answer
27 views

Maximum Liklihood Image Classification; Does this algorithm consider RGB Band values only?

if it is correct that Maximum Liklihood classification algorithm takes into account RGB values of the bands only, then is it useless to stack other bandslike NIR SWIR etc prior to go ahead and use ...
2
votes
0answers
17 views

Stripes and Distortion in classification result when performing maximum likelihood classification in ArcMap

I have trouble performing a supervised classification in ArcMap 10.3. I created training areas and executed the "interactive supervised classification"-tool, which works totally fine and gives back ...
2
votes
1answer
222 views

supervised classification

I am having a problem in creating new signatures in Signature Editor in ERDAS 2014. Whenever I click on the icon (i.e., after selecting the aoi), it shows an error which says "unable to open ...
1
vote
1answer
207 views

Erdas Imagine Error: Performance warning: Covariance calculation requires stack processing but input layer stack isn't suitable. How to solve it?

I am collecting signatures right now and when I am adding them to the Signature Editor Erdas says: Performance warning: Covariance calculation requires stack processing but input layer stack ...
1
vote
0answers
13 views

how do I get percentages of classes in a classified image?

I am using ArcMap 10.3 I have two layers, one classified raster, Landsat based dNBR, where classes show burn severity, and a shapefile containing polygons, drawn based on the dNBR image and that ...
3
votes
0answers
29 views

Classify image using segmentation analysis using QGIS and OrfeoToolbox

My first question on stackexchange (sorry for my english language)! I use stackexchange often to understand GIS principles and workflows. I wasn't able to find a answer. For this project we made a RGB ...
1
vote
0answers
19 views

Working with Mobile LiDAR (extracting walls)

I am currently working on mobile point clouds in order to extract 3D building models in the residential area. I could successfully classified ground, vegetation and building roof lines, but still have ...
4
votes
0answers
23 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
0answers
32 views

How to classify difference surfaces having almost similar Reflectance responses?

I am using ENVI 5.3 to classify a Region of Interest clipped from Landsat 8 OLI. I have already performed calibration of my DNs by transforming it into Radiance and derived Reflectance image using ...
2
votes
1answer
274 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?
2
votes
0answers
48 views

Classification and measurement of feature basing on scan [closed]

It`s not entirely a GIS question, however maybe somebody can help. I need to automatically classify and then measure area of certain elements on image. That image is a scan of a thin wood slice and ...
4
votes
2answers
115 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 ...
1
vote
0answers
14 views

Spectral classification for crops

I'd like to do a classification using a multispectral raster (1 Blue 475, 2 Green 560, 3 Red 668, 4 Red Edge 717, 5 Near IR 840). I'd like to classify the crops (kiwi plants). I tried a few ...
2
votes
0answers
18 views

SAGA 2.2.5 Problem Object Based Image Segmentation

Every time I use the Object Based Image Segmentation with Landsat 8 data I get a segmentated image which looks like a spider's web. The image contains no 0 values. Anyone has a idea how to fix this?
1
vote
1answer
224 views

Extraction of pixels from layerstacked NDVI image

How do I get rice pixels only from layerstack NDVI (modis) or SASI image? I also have a thematic rice image Please tell me how to do in erdas.
2
votes
2answers
37 views

Using SCP image classification to find swimming pools?

i'm currently trying to use the scp image classification plugin to find swimming pools in an aerial image. It is just an RGB image as if it had infra red this'd be a lot easier. Does anyone know how ...
0
votes
1answer
54 views

Remote sensing accuracy assessment - McNemar`s Test

I would like to know how you determine the f12, f21 parameters for use in the McNemar`s test when for example I have two confusion matrices such as below: (where f12 = number of cells misclassified ...
0
votes
1answer
614 views

ENVI 5.2.1 How to do an Accuracy Assessment using test data from a shapefile

ENVI 5.2.1. From a .tiff image (4 bands) I created a Supervised Classification Maximum Likelihood .dat file. Now I want to perform an Accuracy Assessment using test data from a shapefile. I've tried ...
1
vote
1answer
51 views

Extracting above ground features from unclassified LAS [closed]

What's the best way to vectorize features from LAS? I have "Classified" LAS files, however they were never processed for classification. Thus of 181 million points (9 tile sample) about 60% are class ...
0
votes
1answer
20 views

Rule of thumb for selecting ROIs for supervised classification

I'd like to perform a supervised classification using the Semi-Automatic Classification Plugin and a maximum likelihood classification algorithm. I read about a rule of thumb which says "if training ...
0
votes
0answers
7 views

Data type doesn't match error in Sieve filter

I classified some land cover types in aerial image with Erdas Imagine, now I want to remove classification errors showing very small areas. I tried to use Sieve filter, but getting error notification ...
6
votes
1answer
162 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 ...
4
votes
4answers
113 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 ...
0
votes
0answers
35 views

How to export training area information?

I did a supervised classification of a whole Landsat 8 image with 700 Rois (training areas) with the Semi Automatic Classification Plugin. I want to export the class names, the coordinates and the ...
1
vote
3answers
182 views

Classifying individual trees from labelled LiDAR point cloud [duplicate]

I have a classified point cloud for an area of 250*250 square meter, with 1 meter resolution. It has a 5 lakhs points with an average point density of 9 (means around 9 points within a pixel). I ...
4
votes
5answers
1k 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 ...
1
vote
1answer
29 views

Image Classification on Photos From Camera?

A little bit of background: So I have some photos of 1X1 meter plots that were taken with a NIR digital camera. They have been georeferenced, corrected, etc.. I am interested in performing an image ...
0
votes
0answers
27 views

Retrieving raster classes as data type in Python Script tool?

I want to program a python script tool in ArcGIS where the user should be enabled to input a classified raster and, based on this raster, the classes should be selectable. EDIT: As is suggested in ...
5
votes
2answers
141 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 ...
0
votes
0answers
38 views

Finding spectral reflectance bands for classes created from unsupervised classification

I am working on a project that requires separating water and non-water features based on unsupervised classification in ERDAS Imagine 2015. I have taken the original image, and assigned it into 50 ...
3
votes
0answers
36 views

How to use a conditional logic on Impervious Mapping

I am trying to use a logic ( rule -based classification ) to extract built-up area, similar to as suggested by Xu (2007).He uses, three spectral indices, SAVI( Soil Adjusted Vegetation Index), NDBI ( ...
0
votes
0answers
51 views

Maximum Likelihood Classification in ENVI

I am a new ENVI user and I am trying to perform a supervised classification of a Landsat 8 image with the maximum likelihood algorithm. In order to run the classification, I have to insert a Scale ...
2
votes
1answer
18 views

Symbology classification scheme for Solar PV Electricity Generation

I am presenting some data relating to rooftops suitable for solar PV and their potential PV electricity generation. I am mapping the above data for the study area. What would be the best symbology ...
3
votes
1answer
249 views

Classification of above ground LiDAR points in ArcMap

I recently used the LAS Dataset toolbar to classify a .lasd file. The process classified the majority of points as unassigned with the rest being ground points. The study area has many tall buildings ...
1
vote
1answer
37 views

How to define a threshold in Principal Component Image for Urban mapping?

I am working on an Urban mapping and i would like to know how i could define a threshold value for extracting built-up areas from a PC (Principal Component) Image ? I am interesting on how to ...
1
vote
0answers
122 views

ENVI: Postclassification, remove pixels of certain size

I did a classification over multiple Landsat imagery in ENVI 5.1, which turned out not too bad (ice and snow in Cyan in the picture below). Now I am about to do a postclassification to filter out ...
3
votes
2answers
56 views

How to give polygons a classificaton code in ArcGIS?

Does anyone have a trick for assigning polygons a code based on the classification classes? For example, if I symbolize the population of census blocks with 10 classes using Natural Breaks, I would ...
5
votes
1answer
73 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 ...
2
votes
1answer
73 views

NDVI in ENVI: Output format issue

I am working on NDVI in ENVI... the output file is in Envi Standard format... I required it in Envi Classification format, which can be done through Envi Edit Header tool... This requirement is for ...
1
vote
0answers
50 views

Needed help to launch SVM classification in eCognition

I would like if somebody help me to launch SVM classification in eCognition. Have you met any tutorials? I was searching through ecognition community, but there I find only basic KNN supervised ...
2
votes
2answers
59 views

Adding more than one legend in QGIS Print Composer?

I'm using QGIS 2.8.4 and I can't seem to figure out adding more than one legend to my Print Composer. Say I want a larger map and then an inset map -- showing perhaps a different classification/color ...
2
votes
0answers
128 views

Graduated symbols not appearing for all polygons

I'm using ArcGIS 10.2.2. Trying to map some city populations using graduated symbols. Should be simple, but while most of the polygons are being assigned symbols, some aren't. For example, in the ...
2
votes
1answer
42 views

Panchromatic Image Classification GRASS GIS

How to perform an unsupervised classification of a single panchromatic satellite imagery in GRASS GIS? I tried it many times but I keep being prompted for a second image or other images in the ...
1
vote
0answers
21 views

Band Separation from regular cameras

I have removed the IR block filter from a Sony digital compact camera so it has become multispectral (in a way). In addition to that I placed a IR pass filter, so it only captures photos in the ...
0
votes
1answer
27 views

Call Toolbox operators of ENVI from IDL code

Is it possible to call the clustering/classification algorithms included in the toolbox of ENVI (gui) from IDL (source code) and how?
1
vote
0answers
25 views

Normalizing raster data: getting a range of output values as opposed to a Boolean output [duplicate]

I converted a polygon shapefile which defined ED boundaries to raster. The value i based the raster surface on was a population count for each ED. The values ranged from 568 and 18160, as expected, ...
0
votes
0answers
39 views

Adding Masked Classes to unsupervised classification in ERDAS Imagine

Prior to supervised classification of a landsat 8 scene in ERDAS Imagine I masked two classes using the 'Mask' tool [Raster - Geometry - Subset & Chip - Mask] I now wish to add these two classes ...
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 ...