Point Cloud Classification

Classifying point clouds into terrain/objects, can someone explain how the values specifying minimum and maximum object lengths, and height act to classify the point cloud. I’m trying to remove vegetation and other aerial objects.

Hi Jagjit,

The minimum object length is the minimum length that you expect your object to have. For example, if you don’t want to classify cars as object in the point cloud you should put a value that is larger than a car length.

Similarly to the minimum object length, the maximum object length is the maximum length that you expect you object to have.

The minimum object height is the minimum height above which an object in the point cloud will be classified as object. Objects that are higher than this value will be classified as objects (as long as they also fit in the min and max length).

The object group of the point cloud will contain objects that are between the minimum and maximum object length and higher than the minimum object height.

You can find more information about these parameters here:
https://support.pix4d.com/hc/en-us/articles/202557799#label5

However, note that since this tool is still a beta, removing all the vegetation adjusting these 3 parameters can be difficult. You will probably have to do some manual editing of the point cloud to remove accurately the vegetation. Here is how to edit the point cloud:

https://support.pix4d.com/hc/en-us/articles/202560499

But this tool already allows you to perform a first rough classification of your point cloud. We will be working on a better classification tool for future version of Pix4Dmapper.

Regards,

How do we classify points clouds in Pix4D Mapper version 3.1? They took away the option under point clouds tab in the “processing options” box. 

As Thomas… I cannot find the classification option anymore ?

Where can those height and length settings be adjusted?
Thanks!

Hi Miguel,

Thank you for your question.
These parameters were available as a beta feature in previous PIX4Dmapper versions (here an example of version 2.1)

These parameters cannot be set in current PIX4Dmapper version.

Thank you Daniele;
unfortunately, if this is not available at the moment (my version is 4.7.3), this features doesn’t help me.
Why is it not available any more? It does not seem logical to me to remove features from a software.
BR.

Hi @MiguelToril,

The feature was not completely removed from the software but was replaced with a new algorithm.

You can find additional information here:

And in this scientific paper:

I hope this helps.

Cheers.

Thanks for the feedback. I will have a look on it.
BR, Miguel

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Let us know how it goes.

Happy processing!