Don segmentation

[akashverma1995]

I tried the difference of normal(DON) for MLS data. I am facing some issue

1. after loading data in PCLpy, a gap is coming in the input data
2. The difference of normal is not coming properly

I want to remove vegetation from the data, and for that, I am trying to apply don segmentation.
if you have any suggestions please share them with me
and how can I check normal computed by pclpy is correct

and I am using below given code

pc_subsampled = pclpy.octree_voxel_downsample(pc, 0.05)
subsampled = pclpy.octree_voxel_downsample(pc_subsampled, 0.4)

normals_large = pcl.PointCloud.PointNormal()
pc_subsampled.compute_normals(radius=4, output_cloud=normals_large, num_threads=8, search_surface=subsampled)
normals_small = pcl.PointCloud.PointNormal()
pc_subsampled.compute_normals(radius=0.10, output_cloud=normals_small, num_threads=8)

don = pcl.features.DifferenceOfNormalsEstimation.PointXYZRGBA_PointNormal_PointNormal()
don.setInputCloud(pc_subsampled)
don.setNormalScaleLarge(normals_large)
don.setNormalScaleSmall(normals_small)
output = pcl.PointCloud.PointNormal(pc_subsampled.xyz)
don.computeFeature(output)
indices = np.argwhere(output.curvature > 0.4)
output2 = pcl.PointCloud.PointNormal(output, pcl.vectors.Int(indices))

clusters = pclpy.extract_clusters(pcl.PointCloud.PointXYZ(output2.xyz), 0.1, 50, 100000)
assert len(clusters) in range(30, 35)  # there is some randomness to the results

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