Jun-CEN / Open-world-3D-semantic-segmentation

[ECCV 2022] Open-world Semantic Segmentation for LIDAR Point Clouds
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the number of dummy classfiers for nuscenes #11

Closed luoyuchenmlcv closed 1 year ago

luoyuchenmlcv commented 1 year ago

Hi, I see there are 4 unknown classes, {barrier, traffic cone, trailer, construction vehicle}, but the default number of dummy classifiers=3 in your code. If I understand correctly, every incremental class should occupy one dummy classifier once introduced, hence it should be 4 dummy classifiers, could you explain why it is 3 ?

Jun-CEN commented 1 year ago

Hi,

For SemanticKITTI dataset, the number of dummy classifiers should be 3, as we find it has the best performance on the open-set task. For nuScenes dataset, we set the number of dummy classifier as 3 at first for the open-set task. Then we set the dummy classifier as 5 during incremental learning, as the number of dummy classifiers should be larger than unknown classes. Basically, you can set the number of dummy classifiers as 5 for both the open-set and incremental learning task.

luoyuchenmlcv commented 1 year ago

Thanks for your clarification!

luoyuchenmlcv commented 1 year ago

By the way, it seems that the evaluation code only test the mIOUclose, The code for testing AUROC and AUPR for open-set recognition ability is not provided. The most important thing to try to reproduce your reported results is the lambda_th, to classify if it is a novel class or not. How do you set the value? I guess it comes from maximizing classification accuracy between the synthesized and normal point during training time?

Jun-CEN commented 1 year ago

AUROC and AUPR can be evaluated through semantickitti_api and nuscenes_api, which are mentioned in the first 3 lines of README.md. You should store the uncertainty score files and closed-set evaluation files and then use api to get both closed-set and open-set performance.

AUORC and AUPR are threshold independent, so we do not need lambda_th to evaluate the open-set performance. You can check the definition of these two metrics.

luoyuchenmlcv commented 1 year ago

Thanks again! I will carefully understand this api.