[I] RS_AsGeoTiff and RS_AsCOG drop NaN nodata values and write the source file's nodata value instead of the raster's [sedona]

["jiayuasu (via GitHub)" <gi...@apache.org>]

jiayuasu opened a new issue, #3367:
URL: https://github.com/apache/sedona/issues/3367

   ## Expected behavior
   
   `RS_AsGeoTiff` and `RS_AsCOG` should write band 1's nodata value to the `GDAL_NODATA` tag whatever it is, `NaN` included, and write the value the raster currently declares: after `RS_SetBandNoDataValue(raster, 1, -9999, true)` the file should say `-9999`, after `RS_SetBandNoDataValue(raster, 1, null)` it should carry no tag.
   
   ## Actual behavior
   
   Both functions go through the GeoTools `GeoTiffWriter`, which
   
   - never writes a NaN nodata value (`GDAL_NODATA=nan` from a float source is lost on the way out, so the file reads back with no nodata value once #3365 makes the reader keep it);
   - prefers the `GC_NODATA` image property, copied verbatim from the source file, over the nodata value the raster declares, so a value changed or removed with `RS_SetBandNoDataValue` after reading is ignored and the source file's value is written instead;
   - invents a nodata value for integer rasters that declare none (0 for byte bands), which `RasterOutputs.asGeoTiff` currently works around by switching `WRITE_NODATA` off when no band has one.
   
   None of this is adjustable from outside: the guard sits inside `write()`, the helpers it calls are private, and `setMetadataValue` cannot address the `GDAL_NODATA` tag.
   
   ## Steps to reproduce the problem
   
   ```sql
   SELECT RS_BandNoDataValue(RS_FromGeoTiff(RS_AsGeoTiff(RS_SetBandNoDataValue(RS_FromGeoTiff(content), 1, -7))))
   FROM binary_files   -- a GeoTIFF whose GDAL_NODATA is 0
   -- expected -7, got 0
   ```
   
   ## Settings
   
   Sedona version = master (2.0.0-SNAPSHOT)
   API type = Scala, Java, Python, SQL
   Spark version = 3.5
   Scala version = 2.12
   JRE version = 11
   


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Re: [I] RS_AsGeoTiff and RS_AsCOG drop NaN nodata values and write the source file's nodata value instead of the raster's [sedona]

["jiayuasu (via GitHub)" <gi...@apache.org>]

jiayuasu closed issue #3367: RS_AsGeoTiff and RS_AsCOG drop NaN nodata values and write the source file's nodata value instead of the raster's
URL: https://github.com/apache/sedona/issues/3367


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