2008年1月1日 星期二

Learning from Small Number of Examples

In this project, there is a need that user may select several images as query images. I choose discrimintive model as our approach.
Based on the libsvm provided by Prof. Lin Chih-Jen, the algorithm is listed as below:
1. Read the checked images and un-checked images.
2. The checked images are regarded as positive examples. And the un-checked images and other images in dataset are regarded as pseudo-negative examples.
3. If the number of positive examples is N, then 2N pseudo-negative examples are generated.
4. For each loop do
- Construct a bag (training set) that contains N positive examples and 2N pseudo-negative examples.
- Choose the whole image dataset as testing set.
- Call svm_train to generate the model. Due to some parameters (g, C) are adjustable, I use the tools provided by Prof. Lin Chih-Jen to find out the best performance.
- Use the predict call to generate the classification results. The prob. parameter must be set to active.
- Collect the probability table.
5. Use MIN fusion to obtain the final result.
6. Filter out the positive examples in descending order and output to system.