Merge pull request #47 from IGNF/add_remove_dimensions

add fn to remove dimensions into las

.gitignore

@@ -3,3 +3,4 @@ tmp
 __pycache__
 ign_pdal_tools.egg-info
 dist
+*.idea*

CHANGELOG.md

@@ -1,3 +1,5 @@
+- las_remove_dimension: new tool to remove one or many dimensions
+
 # 1.6.0
 - color: choose streams for RGB colorization, and IRC colorization (doc https://geoservices.ign.fr/services-web-experts-ortho)
 - color: detect white images.

pdaltools/las_remove_dimensions.py

@@ -0,0 +1,58 @@
+import argparse
+import os
+
+import pdal
+from pdaltools.las_info import get_writer_parameters_from_reader_metadata
+
+def remove_dimensions_from_las(input_las: str, dimensions: [str], output_las: str):
+    """
+    export new las without some dimensions
+    """
+    pipeline = pdal.Pipeline() | pdal.Reader.las(input_las)
+    pipeline.execute()
+    points = pipeline.arrays[0]
+    input_dimensions = list(points.dtype.fields.keys())
+    output_dimensions = [dim for dim in input_dimensions if dim not in dimensions]
+    points_pruned = points[output_dimensions]
+    params = get_writer_parameters_from_reader_metadata(pipeline.metadata)
+    pipeline_end = pdal.Pipeline(arrays=[points_pruned])
+    pipeline_end |= pdal.Writer.las(output_las, forward="all", **params)
+    pipeline_end.execute()
+
+
+def parse_args():
+    parser = argparse.ArgumentParser("Remove dimensions from las")
+    parser.add_argument(
+        "--input_las",
+        "-i",
+        type=str,
+        required=True,
+        help="Path to the the las for which the dimensions will be removed",
+    )
+    parser.add_argument(
+        "--output_las",
+        "-o",
+        type=str,
+        required=False,
+        help="Path to the the output las ; if none, we replace the input las",
+    )
+    parser.add_argument(
+        "--dimensions",
+        "-d",
+        type=str,
+        required=True,
+        nargs="+",
+        help="The dimension we would like to remove from the point cloud file ; be aware to not remove mandatory "
+             "dimensions of las"
+    )
+
+    return parser.parse_args()
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    remove_dimensions_from_las(
+        input_las=args.input_las,
+        dimensions=args.dimensions,
+        output_las=args.input_las if args.output_las is None else args.output_las,
+    )

test/test_las_remove_dimensions.py

@@ -0,0 +1,67 @@
+import tempfile
+import pdal
+import numpy
+import os
+import logging
+import pytest
+
+from pdaltools import las_remove_dimensions
+
+TEST_PATH = os.path.dirname(os.path.abspath(__file__))
+INPUT_DIR = os.path.join(TEST_PATH, "data")
+
+ini_las = os.path.join(INPUT_DIR, "test_data_77055_627760_LA93_IGN69.laz")
+added_dimensions = ["DIM_1", "DIM_2"]
+
+def get_points(input_las : str):
+    pipeline_read_ini = pdal.Pipeline() | pdal.Reader.las(input_las)
+    pipeline_read_ini.execute()
+    return pipeline_read_ini.arrays[0]
+
+def append_dimension(input_las : str, output_las : str):
+    pipeline = pdal.Pipeline()
+    pipeline |= pdal.Reader.las(input_las)
+    pipeline |= pdal.Filter.ferry(dimensions="=>" + ", =>".join(added_dimensions))
+    pipeline |= pdal.Writer.las(output_las, extra_dims="all", forward="all", )
+    pipeline.execute()
+
+
+def test_remove_all_dimension():
+
+    # get initial data
+    points_ini = get_points(ini_las)
+
+    with tempfile.NamedTemporaryFile(suffix="_add.las") as tmp_las:
+        append_dimension(ini_las, tmp_las.name)
+        with tempfile.NamedTemporaryFile(suffix="_rm.las") as tmp_las_rm:
+            # remove all dimensions
+            las_remove_dimensions.remove_dimensions_from_las(tmp_las.name, added_dimensions, tmp_las_rm.name)
+            points_end = get_points(tmp_las_rm.name)
+            assert numpy.array_equal(points_ini, points_end)  # output data should be the same
+
+
+def test_remove_one_dimension():
+
+    # get initial data
+    points_ini = get_points(ini_las)
+
+    with tempfile.NamedTemporaryFile(suffix="_add.las") as tmp_las:
+        append_dimension(ini_las, tmp_las.name)
+        with tempfile.NamedTemporaryFile(suffix="_rm.las") as tmp_las_rm:
+            # remove one dimension
+            las_remove_dimensions.remove_dimensions_from_las(tmp_las.name, ["DIM_1"], tmp_las_rm.name)
+            points_end = get_points(tmp_las_rm.name)
+
+            assert list(points_end.dtype.fields.keys()).index("DIM_2") >= 0# should still contains DIM_2
+
+            with pytest.raises(ValueError):
+                list(points_end.dtype.fields.keys()).index("DIM_1") # should not have DIM_1
+
+            with pytest.raises(TypeError):
+                numpy.array_equal(points_ini, points_end)  # output data should not be the same
+
+
+if __name__ == "__main__":
+    logging.basicConfig(level=logging.INFO)
+    test_remove_all_dimension()
+    test_remove_one_dimension()