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Is there a way to calculate an accuracy assessment in QGIS?

I have around 300 points. At each point I extracted the value of the pixel. I compared the extracted value with the value which should be there. Now I have a table with two columns: One is the extracted value from the raster, one is the value which I typed in manually (the correct value).

How would I calculate the users accuracy and Kappa with that? Is there a tool to do that?

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    What exactly should be calculated? A simply math expression between those values per row?
    – bugmenot123
    Sep 6, 2016 at 9:55
  • @bugmenot123 whatever needs to be done to get an accuracy assesment (useres accuracy, over all accuracy, kappa, ...)
    – four-eyes
    Sep 6, 2016 at 9:57

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You can use Semi-Automatic Classification Plugin. It has Accuracy assessment calculation, as you can see below, but I didn't try it yet.

There is also a help about the plugin, and Youtube video about accuracy assessment.

enter image description here

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  • Would that tool accept shapefiles, that have already all the information in them? So, I would not create the shapefile with that tool, but rather feed it a shapefile where two columns indicate the extracted value at the pixel, and the other column with the value I typed in manually.
    – four-eyes
    Sep 6, 2016 at 9:46
  • I am not sure but I think it may accept the shapefile that you already have. It is better to read the turorial, because I didn't work on this tool extensively. I mostly use commercial software for such analysis.
    – ahmadhanb
    Sep 6, 2016 at 11:52
  • I worked with this tool (SCP) and its a black box. Sometimes stuff works, sometime it does not... Thats why I am looking for another method.
    – four-eyes
    Sep 6, 2016 at 12:53

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