AIST

Continuing my explorations of FFmpeg for video visualization, today I came across this very nice blog post on creating “pixel array” images of videos. Here the idea is to reduce every single frame into only one pixel, and to plot this next to each other on a line. Of course, I wanted to try this out myself. I find that creating motiongrams or videograms is a good way to visualize the content of videos. They are abstract representations, but still reveal some of what is going on. However, for longer videos, motiongrams may be a bit tricky to look at, and they also take a lot of time to generate (hours, or even days). For that reason I was excited to see how pixel array images would work on some of my material. ...

In some recent posts I have explored the creation of motiongrams and average images, multi-exposure displays, and image masks. In this blog post I will explore different ways of generating keyframe displays using the very handy command line tool FFmpeg. As in the previous posts, I will use a contemporary dance video from the AIST Dance Video Database as an example: The first attempt is to create a 3x3 grid image by just sampling frames from the original image. I spent some time exploring different ways of doing this. It is possible to do it with a one-liner: ...

As part of my exploration in creating multi-exposure keyframe image displays with FFmpeg and ImageMagick, I tried out a number of things that did not help solve the initial problem but still could be interesting for other things. Most interesting was the automagic creation of image masks from a video file. I will use a contemporary dance video from the AIST Dance Video Database as an example: The first step is to extract keyframes from the video file using this one-liner ffmpeg command: ...

While I was testing visualization of some videos from the AIST database earlier today, I wanted to also create some “keyframe image displays”. This can be seen as a way of doing multi-exposure photography, and should be quite straightforward to do. Still it took me quite some time to figure out exactly how to implement it. It may be that I was searching for the wrong things, but in case anyone else is looking for the same, here is a quick write up. ...

Researchers from AIST have released an open database of dance videos, and I got very excited to try out some visualization methods on some of the files. This was also a good chance to test out some new functionality in the Musical Gestures Toolbox for Matlab that we are developing at RITMO. The AIST collection contains a number of videos. I selected one hip-hop dance video based on a very steady rhythmic pattern, and a contemporary dance video that is more fluid in both motion and music. ...