Band Select from Java/Python API

development
2

Following this post Obtaining sigma (backscatter) from Sentinel 1 subset I rewrote the method to this:

def write_rgb_image(bands, filename):
    polarisation = 'B2'
    src_product = ProductIO.readProduct(filename)
    width = src_product.getSceneRasterWidth()
    height = src_product.getSceneRasterHeight()
    tar_product = Product("target", 'GeoTIFF', width, height)
    band_names = src_product.getBandNames()
    BSelectOp = BandSelectOp()
    BSelectOp.setParameterDefaultValues()
    BSelectOp.setSourceProduct(src_product)
    BSelectOp.setParameter('selectedPolarisations', polarisation)
    BSelectOp.setParameter('sourceBandNames', band_names)
    BSelectOp.setParameter('bandNamePattern', '^(B2|B3|B4|B8)$')

    target_product = BSelectOp.getTargetProduct()
    ProductIO.writeProduct(target_product, 'test', 'GeoTIFF')

I’m getting a java.lang.NullPointerException and I don’t get why because I have set all the parameter of BandSelectOp