Creating different types of keyframe displays with FFmpeg

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....

March 1, 2020 · 4 min · 761 words · ARJ

Creating multi-exposure keyframe image displays with FFmpeg and ImageMagick

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....

February 21, 2020 · 2 min · 419 words · ARJ

Motiongram of high-speed violin bowing

I came across a high-speed recording of bowing on a violin string today, and thought it would be interesting to try to analyze it with the new version of the Musical Gestures Toolbox for Python. This is inspired by results from the creation of motiongrams of a high-speed guitar recording that I did some years ago. Here is the original video: From this I generated the following motion video: And from this we get the following motiongram showing the vertical motion of the string (time running from left to right):...

January 24, 2020 · 1 min · 108 words · ARJ