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Classification of Point Clouds

For Pix4D 4.0.18 can classify Point clouds. But when I try import the result of Point Cloud classification with sample dataset as Quarry_group1_densified_point_cloud.las into Global Mapper software, it does not have any information about classification. We use the tool named Filter Lidar Data to view all point clouds and all of them as never classified. Please let me know how to keep full information of Point Cloud classification from Pix4D such as ground point, building, vegetation…

Hi, 

I would proceed as follows for the export: 

  1. Right click the densified point cloud, click Export Point Cloud…
  2. Select the classes you want to keep.
  3. Select .las or .laz file formats. These are the only ones that keep the labels when exported. 
  4. Select a new place to save the point cloud.


If these steps are done, it should be possible to import it in software such as Global Mapper. If I drag and drop the output file we created in step 4 into Global Mapper, I get the following pop-up: 

I would make sure to click “Select All” under point classification, click “OK” and then it should work. 

Here is an article that might give some more information on how to run and export the point cloud classification: https://support.pix4d.com/hc/en-us/articles/115004864586

Let me know if it worked! Thanks.

Dear Pierangelo Rothenbühler,

Thank you for your reply,

There is a problem for me, I am using Pix4D ver 3.2.7 and have not purchased upgrades to version 4.1, so cannot do as your support. Pls provide the available file *.las that be classified by Pix4D ver 4.1.

Kind ragards,

 

Dear Dai Ngoc Le, 

I’m not sure I understand your last request. The only way to get this type of classification outputs is to use a software version from version 4.0.18 or newer.  As you mentioned in your first post, the point cloud classification is available since version 4.0.18 of the software. Please let me know if I misunderstood. 

Regards

Dear Pierangelo Rothenbühler

That is an announcement from Pix4D team to me about new ability of version 4.0.18. Indeed I have not yet this version and still using version 3.2.7.

Hope that you are clearly for my request.

Thank you

There is a problem for me, I am using Pix4D ver 3.2.7 and have not purchased upgrades to version 4.1, so cannot do as your support. Pls provide the available file *.las that be classified by Pix4D ver 4.1.

Kind ragards,

I need a point cloud file in format *.las that is classified with new version. If possible you could provide to me the sample file named as Quarry_group1_densified_point_cloud.las. I want compare the both results of point cloud classification created by old version and new version.
Thank you.

Dear Dai Ngoc Le, 

Here is a WeTransfer link to the Quarry project classified with version 4.1.22 of the software. Note that it will expire in a few days. 
The classification is based on machine learning techniques. The algorithms get trained on datasets with certain features. The closer the dataset you want to classify is to the training data, the better the classification should work. Note that the amount of training datasets is always improved so that the algorithms can perform better on a larger amount of projects.If we the classification is not good enough, you can manually adjust it with the point cloud editing tool

If you want to know more about how the classification works, please have a look at this white paper.

Hope this helps for your comparison purposes!