How to change null values raster values to 0 in QGIS?

Question

I need help... I'm having problems with QGIS. I have some rasters that appear to have null values, even though I reclassified them to obtain a boolean raster :( How can I change the NULL values to 0?

Answer 1

beside @R.K. answer, you can use r.null in grass too.

r.null - Manages NULL-values of given raster map.

EXAMPLES

Set specific values of a classified map to NULL:

r.null map=landcover.30m setnull=21,22

Set NULL-values of a map to a specific value:

 r.null map=fields null=99

i hope it helps you...

Answer 2

I think the RasterCalc plugin should be able to solve your problem. Once you've installed it, you can use the following query (assuming that NULL values corresponds to -9999; you can check this value in Transparency tab of the Layer Properties):

eq( [your_raster]@1, -9999, 0 )

eq means equal to. This tells RasterCalc that all pixels in your raster with NULL values should have their values set to 0. I'm assuming you have a single band raster.