pageturner — Picture Gallery

These pictures were produced with the -pngout option of pt. Place the mouse pointer over the pictures for descriptions.

This picture shows a normal run of pageturner.

The checkerboardish background shows the similarity of an individual point of the pre-recorded pattern file (horizontal axis) and an individual point of the recording (i.e. real time goes from top to bottom). Similar parts are shown in bright yellow, and different parts in dark red.

The blue parts indicate which point of the pattern the algorithm believes I am playing. High probability is shown in bright blue and parts that I am less likely to be are darker.

An ideal run would be a diagonal blue line from top-left to bottom-right and you can see it is more or less the case here. Some "ghost" lines appear when a theme is repeated more than once as the algorithm thinks I might be playing another instance of that theme...

This picture illustrates the feedback feature, for instance when manually turning the pages then starting from anywhere in a page.

The algorithm spreads a number of "sensors" accross the page, and all of them simultaneously try to recognise what is being played. As time goes (downwards), sensors die one by one, until there's only one left (the tenth, counting from the left) which matches the point where I had started playing.

In this picture I played a bit of the piece twice before resuming. You can see the main thread (top) dying off when it notices I'm not playing what it expected, and a second thread (bottom) gradually appears when it recognises that portion again.

Last modified: Thu Feb 11 21:28:45 CET 2010