I understand the examples on the official QGIS page showing bracketed expressions result in 0 or 1 and those integers can be scaled or values added, but I clearly do not understand how to use the MIN and MAX values and every attempt crashes.

I want to "clip" grid values by setting grid values < 1% of the value to that 1% value. I also want to do the same with those above 99%.

I try

(grid < (MAX (grid) - MIN(grid) /100) ) * (MAX (grid) - MIN(grid) / 100)

but this crashes QGIS.

Is this possible? If other commands change every cell, what are MIN and MAX actually doing?

QGIS Raster Calculator page: https://docs.qgis.org/2.8/en/docs/user_manual/working_with_raster/raster_calculator.html

  • 3
    Could you add a link to the documentation that you are referring to? Are you sure that you are not deviding by zero?
    – user30184
    Jun 8, 2020 at 9:04
  • Added link to QGIS page
    – user24007
    Jun 8, 2020 at 10:05
  • On that page I can see Min and Max only in MinX/MaxX, MinY, MaxY which mean the min/max easting-northing coordinates of the image. Is your link correct?
    – user30184
    Jun 8, 2020 at 16:08
  • OK, got the latest QGIS Raster Calculator link now. As an aside, I am looking at ArcGIS at work and there is no Min or Max in it's Raster Calculator to compare with.
    – user24007
    Jun 9, 2020 at 4:26


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