I have a raster layer with pixel values ranging from 0-0.346, which is a result after calculations in QGIS raster calculator (QGIS version 2.18.26). I want to open the same layer in QGIS 3 on another computer to continue my work there. However, when I open in in QGIS 3, suddenly the values ranges from 0-0.404. This is after having compressed the raster together with others to which the same thing happened), uploaded them to my drive, downloaded them and unzipped them on the computer with QGIS 3. Does anyone know what might be the problem?

  • 1
    what type of compression did you use ? Do you reproduce the problem with the uncompressed raster ?
    – radouxju
    Commented Mar 6, 2019 at 13:00
  • Yes, it seems like the issue is not the compression process.
    – A.N
    Commented Mar 6, 2019 at 13:09
  • 2
    and how do you compute the range ? With large images, statistics are built based on a sample of the pixels, but different stats don't mean that you data actually changed
    – radouxju
    Commented Mar 6, 2019 at 13:11
  • In addition to more, I've been calculating shares of raster layers of 30s resolution and multiplying them with each other. The change seem to happen in the process of switching from 2.18 to 3... In all layers, the range seem to become broader; with a lower minimum value and a higher maximum value.
    – A.N
    Commented Mar 6, 2019 at 13:50
  • 1
    As radouxju states, in version 2.18 min max values are calculated by default as a cumulative count from 2-98% of the data. In version 3.xx values are related to the actual min/max values. In that sense it coul be possible that you are facing this. Try calculating in 2.18 the actual min/max values and see if they are the same as in version 3. Another thing you can check in the layer properties/metadata the actual statistics of the layer Commented Mar 6, 2019 at 18:13


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.