Home –  Archive
Monthly Archives: Mar 2016

Head Tilting Detection - Automatic Page Turner for Pianists

Head Tilting Detection (or Automatic Page Turner for Pianists, still undecided about the name 😛 ) is a simple software that emits a Page Down/Up keypress when the user is tilting the head.Photo-3

Since I started learning piano, more than 10 years ago, I had the problem of turning pages. Turning pages is one of the most annoying thing for a pianist: it forces you to waste seconds, interrupt the flow of music, and it affects the way we learn the pieces (e.g. by making the connection between pages really poor, since we usually stop from a page to the next). Several alternatives exist for  turning pages automatically, but they are clumsy and inefficient. Recently I thought about applying my programming knowledge to this purpose.

As more and more pianists are switching from paper to digital scores, it is possible to use a machine learning approach. I designed a simple software that detects when you are tilting your head right/left, and "scroll" down the page accordingly by simulating a page down/up keypress, with in most software will scroll the window down/up - in Adobe PDF, if you "fill one full-page to window", you will turn a whole page (to next/previous one).

Update 28/03/2016: New version for Linux released. You can now rotate/flip your webcam viewer. The sound now works on Windows machine.

WINDOWS 32/64bit (tested on Windows 7, Windows 8, Windows 8.1)

Download Head Tilting Detection (no setup required) - for Windows

LINUX (tested on Ubuntu 15.10)

Download Head Tilting Detection (no setup required) - for Linux

open folder in terminal and type sudo ./HeadTiltingDetection.sh. This bash file will download and install xdotool if not installed already) and the software will be executed.

Instructions

Open the software, wait for the your face to be detected (a green rectangle around your face should appear), then wait for your eyes to be detected (red squares).
At this point select the application you want to send the keypress (for example, a pdf file).
When you tilt the head on one side, the corresponding arrow key signal will be emitted. A green circle should appear on the corresponding side of the camera view, and you should hear a specific sound for the direction you are tilting your head (you can disable the sound).

Adjust the threshold from the slider, disable the sound, or pause the detection from the user interface.

Key points

  • The software is designed for pianists, so with more or less constant level of light, by taking into account slow/random movement, and by considering that pages are usually not turned so often. Plus, instead of just "turning" your page, it will scroll down on the page, with in most of the cases is what you want.
  • For now, the software does not work if you wear glasses. I will maybe work on this in the future.
  • The software uses a Haar feature-based cascade classifiers, with template matching for tracking the eyes, and several heuristics to increase accuracy. A cubic function of the two eyes' degree is used to emit the keypress. The threshold for the keypress can be adjusted.
  • The software has been tested on Windows 7, 8, 8.1. For now there is only a Window version, but I may develop it for other platform in the future. (28/03/16) Linux: Ubuntu version released

Future work

The software is not perfect. Unfortunately, I do not have many hours to dedicate to it. I plan to keep work on it, but not consistently. I'll probably add to this post any minor updates, and create new posts only if there is a major improvement. If you want to collaborate with me for this project, feel free to contact me!

The software uses OpenCV (for the computer vision part) and Qt. It was very nice working with Qt again after so long, and discovering OpenCV was also very interesting. I have a very good opinion about both in terms of usability and capability. Managing to merge both systems was an excellent experience for me.