CS 766 Assignment 3: Locality-constrained Linear Coding for Scene Classification

Saikat R. Gomes (saikat@cs.wisc.edu) & Stephen Lazzaro (slazzaro@cs.wisc.edu)

Contents

  1. Introduction
  2. Hard Code Word
    1. Results
  3. Locality-constrained Linear
    1. Results
  4. Grid Search
  5. Sequential Hierarchy Classifier
    1. Manually assigned clusters
      1. Results
    2. Clusters from K-means
      1. Results
  6. Other Dataset Evaluation
    1. Birds
    2. Butterflies
  7. Other Experiments
    1. Results
  8. Scene Datasets
  9. Code
  10. Git Logs
  11. References

Different Classifiers


SVM Modifications

We experimented with some different classifiers as well as modifications of the SVM classifier with different kernels. We found the SVM to give the best results when using the histogram intersection kernel. Using a radial basis kernel, we retrieved extremely poor results that were near the level of chance.

k-Nearest Neighbor

We also built a simple k-nearest neighbor classifier. This performed extremely fast and gave us decent results with a mean accuracy of about 50% for using k=5 nearest neighbors. However, as expected, that 50% does not compare to our results using SVM.

Neural Networks

Finally, we used the machine learning toolbox of Matlab and tried classifying using a neural network. However, we could not get any meaningful results from this due to the problem of having too many features compared to the number of training examples.