Update README.md

README.md

@@ -114,7 +114,19 @@ const result = geowarp({
   // optional
   // array of band indexes to read from
   // use this if your expr function only uses select bands
-  read_bands: [0, 1, 2]
+  read_bands: [0, 1, 2],
+
+  // optional
+  // polygon or multi-polygons defining areas to cut out (everything outside becomes no data)
+  // terminology taken from https://gdal.org/programs/gdalwarp.html
+  cutline: geojson,
+
+  // if you specify a cutline, this is required
+  cutline_srs: 4326,
+
+  // function to reproject [x, y] point from cutline_srs to out_srs
+  // required if you specify a cutline and the cutline is a different srs than out_srs,
+  cutline_forward: proj4("EPSG:4326", "EPSG:3857").forward,
 });
 ```
 result is