Multi Categories Object Detection System

Description

Learn and experiment with the novel object recognition method called “Using image priors in Maximum Margin Classifiers”.  Your goal is to train classifiers corresponding to different image categories according to the training algorithm specified by the instructor. Each classifier should accept (with high probability) objects from its own category and reject objects from other categories. 

For each category the performance of both linear and kernel classifiers (specified by the instructor) should be compared. The performance is measured by counting the false positives and true positives for each category and for each model.

Data sets

The system should be trained and tested on  101_ObjectCategories data set. This data set contains images of objects belonging to 101 different categories. See Caltech101 web site for details and download.

Main steps

The project consists of the following steps:

Preprocessing

All images first should be resized to 30x24 pixels. All images have to be normalized to zero mean and a unit length, and transformed to cosine transform (use Matlab dct2.m function).

The Training Step

For each one of the categories reserve 20 random images from the current category to create the classifiers.

Since 20 images cannot fully represent the variation in the appearance inside object class, the recognition results will depend upon the choice of training examples. To reduce this sensitivity we suggest to sunning several (5) trials of training/testing and compare the average results.  In order to compare models performance it is important that the randomization will be consistent, i.e. that the same training examples will be provided to each both models.

Training code is provided (contact the instructor to obtain the code)

The CVX_Package must first be installed on your PC (See appendix A at the cvx_userguide for instructions).

The Test Step

The test set should include all the remaining images that were not reserved for the training. The whole procedure (train + test) should be repeated 5 trials for validation. On each trial the random choice of training images will be different.

Results

For each model compute the confusion matrix of a size N on N ( where N is number of tested categories). At the cell k,j report the number of images from class j which were classified as belonging to class k, divided by the size of category j.

Instructor

Tali Buchnik

Phone or email for setting a meeting:

Phone: 8301

Email :  tbuchnik at cs.haifa.ac.il

 

CVX Package

cvx_userguide

Matlab version

 

Optimization Codes

Contact the instructor

 

 Status