I need to transform a large number of Esri ASCII grid files to polygonized WKT format, e.g. as CSV. Currently, I use GeoTools with the ArcGrid reader and a polygon extraction process. For parallelism this function is executed via Spark. Still converting 30-40 GB of the raster data is very slow. Do you see any possibilities to improve performance?
Would you recommend GDAL / OGR over GeoTools for this purpose? Is there another library which is faster?
Also as these are many small files I want to point out that it is related to https://stackoverflow.com/questions/44322914/spark-read-zip-file-which-contain-multiple-files-with-cpu-intensive-parsing where I try to parse the zip files in parallel.