Multi Direction Lee Filter
grid_filter
QgsProcessingParameterRasterLayer|INPUT|Grid|None|False
QgsProcessingParameterNumber|NOISE_ABS|Estimated Noise (absolute)|QgsProcessingParameterNumber.Double|1.0|False|None|None
QgsProcessingParameterNumber|NOISE_REL|Estimated Noise (relative)|QgsProcessingParameterNumber.Double|1.0|False|None|None
QgsProcessingParameterBoolean|WEIGHTED       |Weighted|True
QgsProcessingParameterEnum|METHOD|Method|[0] noise variance given as absolute value;[1] noise variance given relative to mean standard deviation;[2] original calculation (Ringeler)
QgsProcessingParameterRasterDestination|RESULT|Filtered Grid
QgsProcessingParameterRasterDestination|STDDEV|Minimum Standard Deviation
QgsProcessingParameterRasterDestination|DIR|Direction of Minimum Standard Deviation
