Monthly Archives: August 2012

Matrix exponential to the Rodrigues' rotation formula

Last time we have seen where the formula came from and today I will try to describe how to do the matrix exponential by means of sine and cosine of the rotation angle and some multiplication and addition. As we will see … Continue reading

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Rotation matrix to angle-axis

This time I'm gonna go through a process of extracting rotation axis and angle from the rotation matrix . Lets recap some properties of the rotation matrix that we will be using. Is a square matrix. Is normalized, column and row vectors … Continue reading

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Rotation matrix from exponential twist

Last time I described how to derive a geometric derivation of the the famous Rodrigues' rotation formula. While being quite easy to understand there is another way how to get the rotation matrix from the angle-axis representation.  The approach I'm gonna … Continue reading

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Rodrigues' rotation formula

In many areas of robotics, computer vision and graphic is a need to rotate points or objects by certain angle around a given axis. One way to do it is to use Rodrigue's rotation formula. Where the is a skew … Continue reading

Posted in Computer Vision | 4 Comments

Running Skype on an embedded device - video. Part 3

And now something even more interesting..... a Skype video calling from our ARM embedded device. Unlike the SkypeKit desktop version the one for embedded devices supports only H264 over RTP. This is no problem since I would need to use it … Continue reading

Posted in ARM, Embedded, Skype, Software development, Video calling, VoIP | Leave a comment

Running Skype on an embedded device - audio. Part 2

Last time In the article Running Skype on an embedded device. Part 1 I have described how to install and build the SkypeKit API wrapper and the Skype client demo application. I admit it was quite boring mainly because the demo even … Continue reading

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Running Skype on an embedded device. Part 1

Hi all, today is a Skype day. I'm working on one, for now a secret :-), project that requires the Skype functionality and I decided to take you along the route with me. The microprocessor architecture I'm using is ARM, … Continue reading

Posted in ARM, Embedded, Skype, Software development, VoIP | 2 Comments

Hello World

Hi all, It has been a dark and mostly cold summer here in Oxford,UK so far but I cannot complain. I have been very busy with many of my projects including fixing up my house so  the bad weather at … Continue reading

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