+37I have a scenario where I need to convert the bit depth of a raster from 16 bit to 8 bit, or vice versa, but the type should remain the same. ie Gray16->Gray8, Int16 -> Int8, Red8 -> Red16, etc.
Given that the RasterBandInterpretationCoercer does not accept attribute values for the Destination Interpretation Type parameter, is there an alternate method to testFilter for all allowed types, and 14 hardcoded RasterBandInterpretationCoercers?
+19Hi @jdh,
The RasterBandInterpretationCoercer uses the function @ReinterpretRaster. If we run this function in the FMEFunctionCaller transformer, we gain the ability to set the output raster type from a feature attribute.
We can use the RasterBandPropertyExtractor to determine the band type, then map that to its output type in a new attribute for the function.
I am attaching a workspace to illustrate the process.
Hi @jdh, I think you can implement that with Python. Example:
import fmeobjects
class FeatureProcessor(object):
def __init__(self):
interpretationPairs = {
(fmeobjects.FME_INTERPRETATION_UINT8, fmeobjects.FME_INTERPRETATION_UINT16),
(fmeobjects.FME_INTERPRETATION_INT8, fmeobjects.FME_INTERPRETATION_INT16),
(fmeobjects.FME_INTERPRETATION_GRAY8, fmeobjects.FME_INTERPRETATION_GRAY16),
(fmeobjects.FME_INTERPRETATION_RED8, fmeobjects.FME_INTERPRETATION_RED16),
(fmeobjects.FME_INTERPRETATION_GREEN8, fmeobjects.FME_INTERPRETATION_GREEN16),
(fmeobjects.FME_INTERPRETATION_BLUE8, fmeobjects.FME_INTERPRETATION_BLUE16),
(fmeobjects.FME_INTERPRETATION_ALPHA8, fmeobjects.FME_INTERPRETATION_ALPHA16),
}
self.interpretations = {k : v for k, v in interpretationPairs}
self.interpretations.update({v : k for k, v in interpretationPairs})
self.rasterTools = fmeobjects.FMERasterTools()
def input(self, feature):
# Retrieve raster object from the input feature.
raster = feature.getGeometry()
if not isinstance(raster, fmeobjects.FMERaster):
feature.setAttribute('fme_rejection_code', 'UNSUPPORTED_GEOMETRY_TYPE')
self.pyoutput(feature)
# Collect band objects and remove them from the raster.
bands = []
for i in range(raster.getNumBands()):
bands.append(raster.getBand(0))
raster.removeBand(0)
# Update interpretation for each band and append them to the raster.
for b in bands:
before = b.getProperties().getInterpretation()
after = self.interpretations.get(before, None)
if after != None:
b = self.rasterTools.convertBandInterpretation(after, b)
raster.appendBand(b)
# Reset raster to the feature.
feature.setGeometry(raster)
self.pyoutput(feature)
def close(self):
pass