CS4HS Workshop

Posted by Kurt on July 6th, 2010

After a nice relaxing weekend down on the Jersey shore, I flew up to Rochester, NY on Sunday, June 27th. My 6pm flight out of JFK quickly turned into a 9pm departure due to storms in upstate NY. After a rocky landing and a quick ride to the Radisson hotel on campus, I got started on my slides. Something about procrastinating on RIT campus just felt right ;-) After 4 hours of working on the slides, I called it a night and caught a few hours of rest.

CS4HS LogoOn June 28-30th, RIT hosted a 3 day workshop for area math and computer science high school teachers¬†called Computer Science for High School, CS4HS@RIT. The workshop was sponsored by the RIT Computer Engineering department and Google. On June 28th, I gave the workshop’s keynote talk on “Life of a Software Engineer”. I fielded a bunch of awesome questions from the audience of around 100 teachers. In hindsight, I should have anticipated that teachers would have come prepared with tons of questions and should have allocated more time for questions.

After the keynote, I met up with some old professors and advisors and later discussed some future plans for Video CAPTCHA research with my old thesis advisor. And finally, no trip to Rochester would be complete without a trip to MacGregors to sample some of their delicious beer and food with some old friends. After another couple of hours of delays, I landed back at JFK around midnight, grabbed a beer with a friend in the city, and made it back to my apartment by 3am…just in time to grab a few hours of sleep before work in the morning. ¬†I love my life :-)

Balancing Usability and Security in a Video CAPTCHA

Posted by Kurt on July 13th, 2009

This week (July 15th - July 17th), Richard Zanibbi and I are attending SOUPS ‘09 in Mountain View, CA. It’s a smaller conference that’s gotten great reviews and has had some excellent CAPTCHA-related work presented in the past. On Friday morning, I’ll be presenting a paper titled Balancing Usability and Security in a Video CAPTCHA. A reporter from ZDNet.co.uk has already written a short article about it which you can find here.

Paper

The paper can be downloaded here and the slides can be downloaded here. It’s also available at the ACM Digital Library.

Bibtex Entry

@inproceedings{kak-soups09,
	Title = {Balancing Usability and Security in a Video CAPTCHA},
	Author = {Kurt Alfred Kluever and Richard Zanibbi},
	Booktitle = {Proceedings of the 5th Symposium On Usable Privacy and Security 2009},
	Address = {Mountain View, CA, USA},
	Month = {July},
	Year = {2009}
}

Video CAPTCHAs: Usability vs. Security

Posted by Kurt on September 13th, 2008

On September 26th, 2008 I will be presenting some of my work on Video CAPTCHAs at the IEEE Western New York Image Processing Workshop 2008 in Rochester, NY. The workshop will be held in the Imaging Science building at RIT (registration details can be found at the above link). The paper is in the form of a 4 page “extended abstract” and can be downloaded below.

Paper

The paper can be downloaded here or from the RIT Digital Media Library.

Bibtex Entry

@inproceedings{videoCAPTCHAsUsabilityVsSecurity,
	Title = {Video CAPTCHAs: Usability vs. Security},
	Author = {Kurt Alfred Kluever and Richard Zanibbi},
	Booktitle = {Proceedings of the IEEE Western New York Image Processing Workshop 2008},
	Address = {Rochester, NY, USA},
	Month = {September},
	Year = {2008}
}

Breaking the PayPal.com CAPTCHA

Posted by Kurt on May 12th, 2008

The PayPal.com CAPTCHA suffers several weaknesses: fixed font face, fixed font size, no distortions, trivial background noise, and it’s easy to segment. In this experiment, a three step algorithm has been developed to break the PayPal CAPTCHA. The image is preprocessed to remove noise using thresholding and a simple cleaning technique, and then segmented using vertical projections and candidate split positions. Four classification methods have been implemented: pixel counting, vertical projections, horizontal projections and template correlations. The system was trained on a sample of twenty PayPal CAPTCHAs to create thirty-six training templates (one for each character: 0-9 and A-Z). A separate sample of 100 PayPal CAPTCHAs were used for testing. The following success rates have been achieved using the different classifiers: 8% pixel counting, vertical projections 97%, horizontal projections 100%, template correlations 100%. Three of the trained classifiers out perform the 88% success rate of Pwntcha.

Example

Preprocess

  1. Original:
  2. Grey Scale:
  3. Thresholding:
  4. Further Cleaning:

Segment

  1. Segmented:
  2. Padded:

Classify

  • Pixel Counting: 8% Break Rate
  • Vertical Projections: 97% Break Rate
  • Horizontal Projections: 100% Break Rate
  • Template Correlations: 100% Break Rate

Paper

The final paper including MATLAB source code, sample runs, and results can be downloaded here or from the RIT Digital Media Library.

Presentation

A copy of the slides used for a presentation of this experiment can be downloaded here.

Data

The 20 training and 100 testing PayPal CAPTCHA images are available to download here.

Source Code

Complete MATLAB code (281 lines, well commented) for preprocessing, segmenting, and classifying the images is available here.

YouTube Video

Note that this video wasn’t created by me. Skip forward to approximately the 1 minute mark.

Artificial Intelligence in Java

Posted by Kurt on April 8th, 2008

I presented a talk on the different Java artificial intelligence frameworks at the monthly RJUG meeting. The presentation focused on JOONE, but also contained demos of JESS and a brief overview of JGAP. I have used both JOONE (artifical neural networks) and JESS (expert systems) for course projects. My slides from the presentation are available here. Two JOONE code examples were presented: XOR and RJUG Attendance Predictor (requires joone-engine.jar).

Action Classification

Posted by Kurt on April 2nd, 2008

I gave a presentation on a form of unsupervised action classification using spatial-temporal correlations based on the work presented here. My slides from the presentation are also available here.

Change Blindness

Posted by Kurt on March 19th, 2008

I gave a presentation on a form of induced blindness known as change blindness for my Image Understanding course. Change blindness is the the inability to detect large changes in a scene that occur during a saccade or interruption. My slides from the presentation are available here.

OCR using Artificial Neural Networks

Posted by Kurt on February 18th, 2008

Optical character recognition refers to the process of translating images of hand-written, typewritten, or printed text into a format understood by machines for the purpose of editing, indexing/searching, and a reduction in storage size. The OCR process is complicated by noisy inputs, image distortion, and differences between typefaces, sizes, and fonts. Artificial neural networks are commonly used to perform character recognition due to their high noise tolerance. In my Artificial Intelligence course, I explored several OCR techniques which utilize ANN’s.

Paper

My final writeup where I surveyed four OCR techniques which utilized ANNs can be downloaded here.

Presentation

I also gave a final presentation on my research where I compared and contrasted four methods. My slides can be downloaded here.

Seam Carving Project

Posted by Kurt on November 6th, 2007

For my Computer Vision course project, I implemented the seam carving technique by Shai Avidan of Mitsubishi Electronic Research Labs and Ariel Shamir of The Interdisciplinary Center and MERL. My final paper, presentation, and code for my seam carving project is now available.

Paper

My final writeup can be downloaded here.

Presentation

Presentation available here!

Code

Java code available here!
Matlab code available here!

Video

Examples

Original image

Image with 100 lowest energy seams shown

Image with 100 lowest energy seams shown

Image with 100 seams removed (no noticeable artifacts)

Image with 100 seams removed (no noticeable artifacts)

Image with 250 seams removed (artifacts start to appear)

Image with 250 seams removed (artifacts start to appear)

Automated Testing of Web Apps

Posted by Kurt on September 11th, 2007

I presented a talk on Selenium on September 11th, 2007 at a recent RJUG meeting. I was first introduced to the excellent tool at my summer internship at Google this summer. My slides from the presentation are available here.


Modified version of Webby Blue
Copyright © 2008 kloover.com. All rights reserved.
**This is my personal blog. The views expressed on these pages are mine alone and not those of my employer.**