GUI Mockup
In order to implement this we would need three new registries. One for the resampling presets and two for the up- and down- samplers.
The following image shows a brief diagram of the classes.
Drafted code example
Resample Service Provider
package org.esa.snap.core.gpf.ui.resample;
import org.esa.snap.core.datamodel.Product;
import org.esa.snap.core.datamodel.RasterDataNode;
public interface ResamplingProvider {
String getName();
boolean isCompatible(Product p);
ResampleMethodology getResampleMethod(RasterDataNode raster);
}
I'm not yet sure about the upsampling and downsampling in ResamplingMethodology. Maybe we should define a common interface for both. Additionally it would be good to make use of the implementations of org.esa.snap.core.dataop.resamp.Resampling. And the interpolation and aggregation operations also need to be extended by a SPI or at least should be retrieved by ResamplingProvider. Here a bit more of thinking is probably needed.
Resampling method
package org.esa.snap.core.gpf.ui.resample;
import org.esa.snap.core.gpf.common.resample.AggregationType;
import org.esa.snap.core.gpf.common.resample.InterpolationType;
public class ResamplingMethod {
InterpolationType upsampling;
AggregationType downsampling;
boolean isEditable;
}
This is how the parameter xml file could look like.
GPF Parameter XML
<parameters>
<referenceBand>B1</referenceBand>
<!-- Still supported but deprecated
<upsampling>Nearest</upsampling>
<downsampling>First</downsampling>
<flagDownsampling>First</flagDownsampling>
-->
<!-- if empty the the default is used -->
<resamplingPreset>S2_MSI_RESAMPLER</resamplingPreset>
<!-- over rules the settings by the resampling preset-->
<bandResamplings>B2:First,B3:First,B4:First,B5:Median</bandResamplings>
<resampleOnPyramidLevels>true</resampleOnPyramidLevels>
</parameters>