Tuesday, January 24, 2006

BareHandCALI with marks

Extending the work developed with Ricardo Jota in BareHandCALI, we integrated in this prototype the mark detection algorithms implemented by the MultiModal Painter team. It is now possible to see on screen the features extracted by CALI from hand poses, using both mark or markerless detection.


Wednesday, January 18, 2006


In the last couple of days, I have been, with Ricardo Jota, developing a prototype to test the behaviour of CALI library in hand pose detection. We had just finished the preliminary version of BareHandCALI. This version uses a standard web cam and simple computer vision algorithms to detect hand contour. This contour is analysed by CALI and extracted features are presented on screen.

BareHandCALI analysing a hand gesture.

Friday, January 13, 2006

Reading XML with TinyXml

The next version of EditION tool should support template-based entities. These templates would be specified in XML files. To implement this feature, I need to integrate a XML parser into my VC++ code. After comparing a few libraries, I chose TinyXml. This simple, small, C++ XML parser is powerfull enough for my need and very easy to learn. It took me only a couple of hours to learn how to use this parser and it was very easy to integrate in my code. I strongly recommend TinyXML to anyone who wants to manipulate XML data in C++.

C++ versus MatLab

After a discussion with the MultimodalPainter senior students regarding performance of RGB to HSV conversion algorithm in MatLab, I decided to compare the time needed in MatLab and C++ compiled files to run a very simple algorithm. To that end, I wrote the following pseudo-code in both programming languages:

Function SimpleCycle(Matrix M) {
ACC is a dummy variable
ACC = 0

for each line L in M
for each column C in M
ACC = ACC + value stored in M(L,C)

return ACC

Using as input an integer matrix M with size 350x350 , this simple algorithm proved to be a good choice to show the performance differences in MatLab and C++. Below are the results obtained in informal tests:

Based on these results I made no comments. I just want to point out that the test programs took less than five minutes to write and run from scratch in MatLab, but more than twenty minutes in C++ (including the matrix creation and time measuring routines incorporation).

Tuesday, January 10, 2006

Freeing space in server

I've spent a couple of hours "helping" our server administrator. To that end, I backed-up of my files in the group server and then I made a selective clean up. This way I freed more than 200MB from the "/home" volume. Unfortunately, I am not the major responsible for the lack of disk space and this 200MB means less than 1% of total volume size.

Thursday, January 05, 2006

BibTeX in resources page

I added a field for the BibTeX reference in my PhD resources page. Using JavaScript, XML and XSL I inserted a small button in each entry to open a pop-up window with the complete BibTeX reference, when it exists for that entry. One example of this new feature can be viewed in entries of "3D Models Retrieval" resources page.

Tuesday, January 03, 2006

Camera-ready version submitted to WSCG

The camera-ready version of our paper titled "A Calligraphic Interface for Managing Agents" was submitted to 14th. International Conferences in Central Europe on Computer Graphics, Visualization and Computer Vision (WSCG 2006).