Tool to compute raster difference of DEMs
A Python environment with GDAL and NumPy available.
Typical intended usage involves the following input datasets:
- A VRT of "old" raster data
- One tile of "new" raster data
This will output:
- One tile of the "new minus old" raster difference
With a VRT of "old" input data, a GeoTIFF file of "new" input data, and writing to an output GeoTIFF file, a command could look like this:
python demdiff.py old.vrt new_1km_NNNN_EEE.tif diff_1km_NNNN_EEE.tif
For further details, see the script help using python demdiff.py -h.
For computing raster differences of large areas, it is intended that this script be called on a per-tile basis (retaining the same "old" VRT for each call). Batch processing of tiles may be implemented by calling this script from GNU Parallel or similar.