QGIS Raster calculator calculates „-inf, inf“ instead of no-data

Question

I am trying to extract Vegetation from an aerial image.

First I calculated a DEM for vegetation height and a binary image (0,1) for cover. Then I divided DEM by binary. Result was a raster with vegetation height data and “no-data”, which is what I want. This worked very well, until recently.

Suddenly I get “inf” instead of no data. I even tried to reproduce previous results and this is now happening there as well. I honestly have no idea what has changed. To reproduce the previous calculations I used raster images that definitely have worked before, but now they do not.

Has anyone any idea how I can get back my “no data” again? Alternatively how to deal with inf?

Answer 1

Approach

You may want to convert this inf value to Nan or NoData. you can easily do it by running raster operation like Self equals. x==x

1. For all real values, this will be True.
2. For all Nans, NoData, or Inf, -Inf. This will be False.

So you will get a binary raster.

Answer 2

Well I don't know why the raster calculator did not work, why saga calculator did not work. But using the grass r.mapcalc.simple did work.

I literally did not change anything but the calculator and got my result.