Early Birds on the first day of spring

Getting up early is worth it from time to time. When I woke up this morning to do the stuff I needed to do (mounting a shelve on the wall, doing some tax payment stuff and putting ads up for my beloved analog body and lenses), my lampshade was hanging nicely in the morning sun, so I decided to take a picture of it.
I guess it’s nice because of the timing and all, with today being the first day of spring. The spring sun coming through my window was nice to see.

The colors have given me hell. It took me about a minute to take the proper picture, but getting the colors correctly took me a buttload of time. I even tried it in black and white…

CS4243 – Digital Image Stabilization

CS4243 – Digital Image Stabilization

During my stay at NUS I followed a course on Computer Vision by Terence Sim. The course was partly a project that I did with Florian Kock and Samuel Martin. Our self-assigned subject was an image stabilization algorithm.
This page shows you the result of our algorithm and the slides of the final presentation. The slides can be seen by clicking on the image to the right.

Below is a result video of our algorithm. The algorithm is based on removing the high-frequency movements found in video. In order to do so, three steps had to be taken.

Step 1: Finding the movement
In order to find the movement, we calculated the difference in position, rotation and zooming of every two succeeding frames. This was done by finding corresponding points in every two frames, selecting the best ones and calculating the homography.
Finding corresponding points was done with the Shi-Tomasi algorithm to find valuable features to track and the pyramidical Lucas-Kanade optical flow calculation.
Because the result was still pretty noisy, we iterated the calculation of the homography, removing the points that had a too large error at every step.

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Slide 10Step 2: Averaging the movement
For every frame a moving average was taken in order to remove the high-frequency movement. Because of the use of homographies, this was not as straightforward.
This lead to homographies that, once applied to the original frames, correct the movement by removing the unwanted movement, but keeping the intended movement.

Step 3: Compensating for the movement
In the last and final step, all the frames were transformed according to the calculated homographies. An extra step is taken by cropping the image so that the image is filled entirely in every frame.

The result
The result is shown below. The first frame is the uncorrected movement. In the middle frame the frames are corrected, it shows that every frame can be rotated, shifted and enlarged in order to compensate for the shaking. The last frame is the final result where a number of pixels are taken from the sides and top and bottom.

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Stabilized Video

36 hours of Corbusier

Our editorial staff had a small teambuilding holidays in Marseille. It was pretty good but we did not do too much. The flight was 10 euros for a return flight, so we decided to go there. We stayed for 2 days and saw the neighborhood built by Marseille’s architect Le Corbusier which was pretty awesome. A lot of concrete buildings with non-concrete shapes I guess. I don’t know too much about architecture, but I still took a number of pictures and pretended to be amazed. 

Intermania editorial staff
Intermania editorial staff

For the rest we did typical French stuff, like eating bread with cheese, drinking wine and walking around. Marseille was a decent thing to do and our team is built again. Check out the pictures if you want.