Compression of output LULC

[vwvbrand]

The output enriched LULC in enrich-lulc component should be compressed and translated to Cloud Optimised Geotiff (COG) for web services of data cubes.
So, two export options should be available:

• compressed (LZW), COG (default)
• non-compressed, GTiff

[vwvbrand]

The in-built solution for the function write_raster in enrichment\lulc_enrichment_wrapper.py is the following:

def write_raster(self, output_data:any, output_ds:any, output_raster:str, nodata_value:int, compress:bool):
        """
        Write a new raster dataset from the given data array.

        Args:
            output_data (np.array): data array to write to the raster
            output_ds (gdal.Dataset): dataset of the input raster
            output_raster (str): path to the output raster dataset
            nodata_value (int): no data value for the output raster
            compress (bool): if True, compress by LZW type and save as a Cloud Optimised Geotiff.
        """

        # export as a temporary raster if compress is defined
        temp_raster = output_raster if not compress else output_raster + "_tmp.tif"

        # get the driver to write a new GeoTIFF
        driver = gdal.GetDriverByName('GTiff')
        out_ds = driver.Create(temp_raster, output_ds.RasterXSize, output_ds.RasterYSize, 1, gdal.GDT_Byte)

        # set geo-transform and projection from the input raster
        out_ds.SetGeoTransform(output_ds.GetGeoTransform())
        out_ds.SetProjection(output_ds.GetProjection())

        # write the data to the output raster
        out_band = out_ds.GetRasterBand(1)
        out_band.WriteArray(output_data)

        # set nodata value 
        out_band.SetNoDataValue(nodata_value)

        # flush and close
        out_band.FlushCache()
        output_ds = None
        out_ds = None 

        if compress:
            print("Saving enriched LULC as a compressed Cloud Optimised Geotiff...")

            # open temp_raster as a GDAL dataset before passing it
            temp_ds = gdal.Open(temp_raster, gdal.GA_ReadOnly) 

            cog_driver = gdal.GetDriverByName("COG")
            cog_driver.CreateCopy(
                output_raster, temp_ds,
                options=['COMPRESS=LZW', 'BIGTIFF=IF_SAFER', 'OVERVIEWS=AUTO']
            )
            
            temp_ds = None
            os.remove(temp_raster)

        print(f"Output raster saved to {output_raster}")

To call the function:

self.write_raster(output_data, output_ds, lulc_upd, nodata_value, compress=True)

It is proposed to add compress parameter to @app.command("enrich-lulc") in main.py.