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?

  • 1
    What exactly should be calculated? A simply math expression between those values per row? – bugmenot123 Sep 6 '16 at 9:55
  • @bugmenot123 whatever needs to be done to get an accuracy assesment (useres accuracy, over all accuracy, kappa, ...) – Stophface Sep 6 '16 at 9:57

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

  • 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. – Stophface Sep 6 '16 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 '16 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. – Stophface Sep 6 '16 at 12:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.