*CMSC848F - Assignment 4* *Submitted By: Akashkumar Parmar* *UID: 118737430* *PointNet Based Architecture* Classification Model =============================================================================== Model's best accuracy achieved: 0.9727 Visualization of a few random test point clouds and the predicted classes for each:
        Point Clouds                 Ground Truth class                Predicted class     
Ray Visualization              Chair                         Chair



Ray Visualization              Chair                         Chair



Ray Visualization             Vase                          Vase



Ray Visualization             Lamp                          Lamp


Visualization of wrong class prediction:


Ray Visualization             Vase                          Lamp



Ray Visualization             Lamp                          Vase

Interpretation: The Classification model performance is overall good. It is only failing for some objects that seem to be very close to another class. For instance, the vase is having a shape of lamp, and the lamp is having a lot of similaries with a flower vase. Therefore, such images are ambiguous for the model and makes the model to mispredict.

Segmentation Model =============================================================================== Model's best accuracy achieved: 0.8888 Visualization of a few Segmentation results with corresponding ground truth:
        Ground Truth                 Prediction                 Accuracy     

        
Ray Visualization Ray Visualization           0.9725


Ray Visualization Ray Visualization           0.9515


Ray Visualization Ray Visualization           0.9506

Segmentation of Bad Prediction with lower accuracy:

Ray Visualization Ray Visualization           0.5632


Ray Visualization Ray Visualization           0.6494

Interpretation: The Segmentation model performance is overall good. It is only failing for some objects that are difficult to segment. For instance, there are some bad performaed cases for large overlaps between different parts of the sofa, or between those parts that are not clearly seperated. Therefore, such images are ambiguous for the model and makes it very difficult for the model to segment clearly.

Robustness Analysis =============================================================================== Experiment 1: Rotate the input point clouds -------------------------------------------------------------------------------

Classification Visualization:

Rotation Angle   Visualization    Ground Truth class   Predicted class   Accuracy

      0         Ray Visualization           Chair             Chair         0.8289

        

      10        Ray Visualization           Chair             Chair         0.8216

        

      20        Ray Visualization           Chair             Lamp          0.6075

        

      30        Ray Visualization           Chair             Vase          0.3410

        

      40        Ray Visualization           Chair             Vase          0.2717

        

      90        Ray Visualization           Chair             Vase          0.2203

        

      180       Ray Visualization           Chair             Vase          0.5005


Segmentation Visualization:

Rotation Angle   Ground Truth     Prediction            Accuracy

      0         Ray Visualization Ray Visualization           0.7693

                

      10        Ray Visualization Ray Visualization           0.6578

                

      20        Ray Visualization Ray Visualization           0.5727

                

      30        Ray Visualization Ray Visualization           0.5420

                

      40        Ray Visualization Ray Visualization           0.5360

                

      90        Ray Visualization Ray Visualization           0.3240

                

      180       Ray Visualization Ray Visualization           0.2420

Interpretation: From the results, we can tell that the test accuracies decrease for both the Classification and Segmentation models. For Classification model, the model performs poorly when the angle is increased. However, at 180° the model showed a better accuracy, because the chair looks like a chair, it is just inverted. For the Segmentation model, the accuracies fall with the increase in angle.

Experiment 2: Change number of points -------------------------------------------------------------------------------

Classification Visualization:

Number of Points   Visualization    Ground Truth class   Predicted class    Accuracy

      50         Ray Visualization           Chair             Lamp            0.3034

        

      100        Ray Visualization           Chair             Lamp            0.5519

        

      500        Ray Visualization           Chair             Chair           0.8006

        

      1000       Ray Visualization           Chair             Chair           0.8289

        

      5000       Ray Visualization           Chair             Chair           0.8331

        

      10000      Ray Visualization           Chair             Chair           0.8289


Segmentation Visualization:

Number of Points   Ground Truth     Prediction            Accuracy

      50        Ray Visualization Ray Visualization           0.8845

                

      100       Ray Visualization Ray Visualization           0.8856

                

      500       Ray Visualization Ray Visualization           0.8870

                

      1000      Ray Visualization Ray Visualization           0.8960

                

      5000      Ray Visualization Ray Visualization           0.9200

                

      10000     Ray Visualization Ray Visualization           0.9400

Interpretation: From the results, it is evident that with number of points, the accuracy increases for both the tasks - Classificationa and Segmentation. However, it is seen that after certain number of points, the accuracy gets stagnant and number of points is not an effective parameter then. For instance, in the Classification task the accuracy is about 0.82-0.83 for the number of points more than 1000. Also, it is the same case for class prediction. After, 1000 points, the model predicts the correct class.