Questions tagged [confusion-matrix]

A confusion matrix contains information about actual and predicted classifications done by a classification system.

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How to exclude/eliminate invalid areas (such as NoData, cloud, water, etc) from raster so that it does not effect the accuracy assessment?

I have two classified raster (snow cover % 10-100) one is prepared from coarse resolution and another is from finer resolution. I am doing accuracy assessment and matrix calculation of snow cover %. ...
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Accuracy classification in Google Earth Engine

I'm trying to perform a supervised classification of a composite image from a Sentinel-2 time series. I'm using cart as classifier and a set of points as trainers. Once computed the classification I'm ...
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When creating a confusion matrix, can you have more ground-truth points than the recommended 10-times the number of classes you have?

Using ArcGIS Pro, I classified a field of grain sorghum (supervises, pixel-based support vector machine) using 5 classes: Soil, Shadows, Leaves, Heads, and Ground targets (this was a UAS study). The ...
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Get a Confusion matrix in QGIS from two vectors

How and with what QGIS tools can I get a confusion matrix from a vector polygon layer as a verifiable classification and a vector point sample layer as a reference classification? That is, if the ...
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Splitting up a region into training data and validation data for Landsat7 classification

I am building a classifier for Landsat7 by using MODIS land cover classification. My goal is to split up my region of interest into 80% being training data and 20% being validation data (with a ...
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Adding random points inside shapefile using ArcGIS Pro for matrix check

I have a vector shapefile for each landcover class, with multiple features. How can I add random points inside the shapefile using ArcGIS Pro for matrix check? For example, for Built landcover ...
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Change size to the squares of the confusion matrix [closed]

I have a problem with size in the 'plot_confusion_matrix', the squares of the confusion matrix appear cut off. I would like to solve this problem. svc = SVC(kernel='linear',C=1,probability=True) svc....
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81 views

Confusion matrix from supervised learning

I am performing a supervised classification in GEE and want to verify how well my classifier has got trained. For this, I found a method confusionMatrix() and my respective program is var training = ...
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385 views

Generating confusion matrix using classified image with geotiff format?

I am working on yielding a confusion matrix with importing an image which is a geotiff format. After classified by a python program, The image has two values (two classifications). However, when I ...
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982 views

Confusion Matrix R

I'm having some problems to understand the result of my confusion matrix. Here is my case: I've run a classification (random forest) on a satellite image. To do so, I created 50 random points for ...
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455 views

Ground truthing with Google Earth

I need to obtain ground truth data of Google Earth for a certain region for the purpose of constructing confusion matrix. The data should correspond to Landcover classes. My main aim is to construct ...
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Classification validation: Trouble with the Confusion Matrix

I'm supposed to validate my supervised classification with a Confusion Matrix, but I'm having a hard time getting what I should use as a comparison. At first, I used the same ROIs I created for ...
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Confusion matrix in ArcGIS 10.3

How can I get a confusion matrix using specific columns in two different rasters in ArcGIS ? I have one raster of risk classes 1,2,3,4 and another raster of land cover A, B, C,D. I am looking for a ...
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Supervised Random Forest in R

I did an image classification using random forest algorithm in R. I got the result but I do not understand what does the confusion matrix shows ? I mean what does the rows and column show? These are ...
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5k views

Random Forest out of the bag and confusion matrix

I have implemented Random Forest classifier to classify remote sensing data in R. The original code comes from here: How to perform Random Forest land classification? Everything works fine, but what ...
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How to interpret accuracy assessment results for classified data?

eCognition has the ability to perform an accuracy assessment for classified data by using an error matrix based on a TTA mask. The image shows the results of the accuracy assessment. Is there a ...
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681 views

R: creating an error matrix from two rasters

I have two land use rasters (6 classes each) and I'd like to create an error matrix (errors of omission and commission) from them both. The premise is that I have a very fine 'base' raster and have ...
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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 ...
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Doing Accuracy Assessment using test data from shapefile in ENVI?

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 ...
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Building confusion matrix for image classification using SAGA?

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 ...