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During the Spring 2013 semester, we were hard at work, adding a lot of improvements, including better search and navigation. A power failure that took the main server offline in the middle of the semester, tested our backups and preparedness to handle unexpected outages.

In my previous update (, I mentioned the three new members who joined the SLIC team. Here's an overview of what the SLIC team focused on, and who was in charge of each of the areas:

Segmentation Groundtruth

Break up a video into segments by matching slides to the frames in which they appear.
Creates continuous segments, each featuring a single slide or denoting a segment where no slide was shown.


  • measure how well automatic video-to-slide matching algorithm works
  • compare its results to the human-generated output
  • measure the accuracy to adjust the algorithm to perform better

Click on the image above to see the groundtruth interface layout.

Segmentation Evaluation

Input: segmentation file

Frame #    Slide #
000001    001
000030    001
000300    002
000330    002
000360    002

Input two files with frame and the slide match numbers
Compute the percentage of correct matches between the two files
Show the visual differences in a webpage: frame image and the slide matches for each file

The purpose of this work is almost the same as with the segmentation groundtruth work. We also adapted the script to work with the legacy segmentation format.

Upload Interface


  • a web-based administration interface to allow for management of various database elements
  • upload the required video and presentation files
  • monitor the progress of a presentation through the processing stages

Log-in authentication.

Adding a new presentation.

Listing all available presentations.

SLIC Portal web interface

I described most of the work on the SLIC interface in my previous blog post. Adding the navigation tree was the major accomplishment of the spring semester. We also spend time on writing  documentation and end-user help features for the SLIC page.

Tiled view of the presentations.

Sorting presentations by various criteria.

Slide matching code

I am continuously researching and implementing new approaches, which will improve the heart of the SLIC project – the slide-to-video-matching code. The transformations that I calculate in my code, not only increase the accuracy of matching slides to the corresponding video frames, but will also contribute to the aesthetic quality of the resulting videos. Some of the improvements will include backprojecting high-quality slides into the video, controlling the transparency of a speaker if a slide has been projected over them, and automatically brightening and color-correcting the scene. Ultimately, the results of this work will give the user much better control of the overall presentation-viewing experience.

These features and updates will allow students to incorporate the SLIC Portal into their studies. We are ready to ask students in the ISTA / CS classes to test-drive the new interface and provide their feedback. In the near future, it would be possible to conduct a study to scientifically show the e?ectiveness of this system in helping students learn and review the material.

We have implemented a lot of changes to the web interface, making it more robust and user-friendly. Look for a new release of the SLIC Portal interface soon!

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