Remove white areas

You can try the RasterInterpretationCoercer.

This we have tried but it always led to an error message

What settings did you try and what was the error message?

Error:

RasterInterpretationCoercer_<Rejected>: Termination Message: 'RasterInterpretationCoercer output a <Rejected> feature. To continue translation when features are rejected, change 'Workspace Parameters' > Translation > 'Rejected Feature Handling' to 'Continue Translation''

@fluusha

You need to check the rejected object. There will be a message specifying (if your lucky) the error in more detail.

What is the input raster? Do you have a sample?

8 bit:

rgba32 = 4x8

rgb24 = 3x8.

only 8 bit

If it's PNG it's probably using a pallette. Try the RasterPalletteResolver first, then the RasterInterpretationCoercer.

bithdept (Bittiefe) doesn't mean its a single band png.

Check the png by using a datainspector and look at the feature information window.

Or use a rasterpropertyextractor to get the info.

It hink @redgeographics is right:

I did this on a png after adding a pallete and get the error u have:

RasterInterpretationCoercer_<Rejected>: Termination Message: 'RasterInterpretationCoercer output a <Rejected> feature. To continue translation when features are rejected, change 'Workspace Parameters' > Translation > 'Rejected Feature Handling' to 'Continue Translation''

@ReinterpretRaster: In RASTER mode, if any bands contain palettes then the requested interpretation may only be one of 'UINT8, UINT16, UINT32'

So either use unisgned 32 (uint32) or as Red said, remove the palette.

Resolving replaces the bandcell values with the palette values. I wonder if you want that.