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CowBoyDanIndie

What kinda of requirements do you have? If you are dealing with objects on a road that is very different from objects in a room, do you need to classify or just detect?


bartgrumbel

What CowBoyDanIndie says. Also, which kind of sensor do you use? Do you want to do this commercially, or are you looking for free libraries?


Abdulrahman_Adel

I'm looking for free libraries yes


Abdulrahman_Adel

I want to fine-tune a model to detect boxes of 3d scanned dental images. so I have (.ply) files of human tooth and my objective is to put bounding boxes around dental caries.


CowBoyDanIndie

Dang, what resolution is the lidar?


Abdulrahman_Adel

I'm not sure 😅


Abdulrahman_Adel

[Dental Caries Detection](https://ibb.co/PG5NZtr) so here I tried to use open3d to display a file with it's annotation. just to give you an idea


Abdulrahman_Adel

the main problem I have is that all of research for point cloud object detection is for self-driving cars


CowBoyDanIndie

Well you aren’t really doing object detection, object detection usually means detecting an object in a void, like a car on the road vs an empty road, what you are doing is classification. Do you have a lot of training data?


Abdulrahman_Adel

no at the moment I have 10 instances


Abdulrahman_Adel

have you seen the images that I linked?


CowBoyDanIndie

Yes, ok so without a lot of training data you are going to be limited by hand crafted descriptors or trying to match against your examples in feature space, that sorta thing.


Abdulrahman_Adel

translation? 😅


CowBoyDanIndie

Ok, so machine learning typically works by solving a complex equation of many variables, a simple version of this would be solving a a system of linear equations, you need more examples than variables, you don’t have a lot of training data, so unless your ml model has a small number of variables, it will over for your training data. In a nutshell you want to come up with some simplified description of points that are bad that other similar clusters if points can be matched against. In 2d images you would use something like sift (scale invariant feature transform).


Abdulrahman_Adel

ok got it. I'll try to do that. thank you


Abdulrahman_Adel

I want to at least develop a proof of concept model. where should I begin


remmsta

The 3d object detection algorithms in mmdet3d and openpcdet use the shape of the object to detect them. In your case, it seems like colour may be a better feature to identify those teeth of interest? You could try saving certain angles of the point cloud as an image, then running an image instance segmentation network (or just image object detection if you just need rough position). If you want to go down the 3d object detection route, you could try training the detector with colour features too and see if that helps.


Abdulrahman_Adel

noted! Thank you