fix: force a alpha band on all imagery if a cutline is present (#264)

* fix: force a alpha band on all imagery if a cutline is present

* refactor: fixup lint

* refactor: missing import

scripts/gdal/gdal_preset.py

@@ -1,4 +1,4 @@
-from typing import List
+from typing import List, Optional
 
 from linz_logger import get_log
 
@@ -82,19 +82,22 @@ def get_gdal_command(preset: str) -> List[str]:
     return gdal_command
 
 
-def get_cutline_command(cutline: str) -> List[str]:
+def get_cutline_command(cutline: Optional[str]) -> List[str]:
     """
     Get a "gdalwarp" command to create a virtual file (.vrt) which has a cutline applied and alpha added
     """
 
-    return [
+    gdal_command = [
         "gdalwarp",
         # Outputting a VRT makes things faster as its not recomputing everything
         "-of",
         "VRT",
-        # Apply the cutline
-        "-cutline",
-        cutline,
         # Ensure the target has a alpha channel
         "-dstalpha",
     ]
+
+    # Apply the cutline
+    if cutline:
+        gdal_command += ["-cutline", cutline]
+
+    return gdal_command

scripts/standardising.py

@@ -99,10 +99,10 @@ def standardising(file: str, preset: str, cutline: Optional[str]) -> FileTiff:
 
             optimized_cutline = optimize_cutline(input_file, input_cutline_path)
             get_log().info("optimize_cutline", optimized_cutline=optimized_cutline, path=file)
-            if optimized_cutline:
-                target_vrt = os.path.join(tmp_path, str(ulid.ULID()) + ".vrt")
-                run_gdal(get_cutline_command(optimized_cutline), input_file=input_file, output_file=target_vrt)
-                input_file = target_vrt
+
+            target_vrt = os.path.join(tmp_path, str(ulid.ULID()) + ".vrt")
+            run_gdal(get_cutline_command(optimized_cutline), input_file=input_file, output_file=target_vrt)
+            input_file = target_vrt
 
         command = get_gdal_command(preset)
         command.extend(get_gdal_band_offset(input_file))