RLPF.ar

Monday night was the annual Mid-Autumn Festival, also called "Moon Cake Festival" in honor of the traditional dessert. I did not have moon cake at home, but I did meet a friend for dinner at a nearby Hunan-style restaurant. Spicy! Walking through the neighborhood on the way home, I saw families lighting lots of candles and sticking them between the paving tiles in the sidewalks. I wish I had brought the camera.

My department at school had some spare moon cakes to give me -- tackiest ever. Yes, those really are Mickey Mouse, Snow White and Winnie the Pooh.

I've been lax on blogging again. Settling into coursework has taken a bit of time (and don't get me started on the struggles to schedule nine -- nine! -- small group lessons around the students' other classes), on top of some personal issues.

In the midst of all that, I've been trying to get motion data out of my laptop's webcam, with the goal of driving the Torso section of Affectations by video in a performance later in the fall. As of this morning, that is working! It's a simple technique: using a gussied-up frame-difference technique to see where in the picture the motion is. (If the pixel values changed in an area of the image from one frame to the next, then something moved there.) Then I'm dividing that result into a 5x5 grid, and measuring the amount of movement (sum of the pixels in that slice) and the "center" of the movement. From there, it's straightforward to format those measurements as an Open Sound Control message and pass over to SuperCollider.

I thought this would be fairly crude, but I find myself surprised how closely the data reflect the shape of the movement at any given moment (video). I thought it would just give me a rough outline, but the movement is actually recognizable in the "test" data-plot window.

For this, I'm using the gridflow extensions to puredata. Lest anyone need any reminders why I dislike graphical patching... (You don't want to see the mess inside [pd iter2d]... trust me... that would be clear and easy to read as a nested loop in a proper programming language, but patching? Nightmare.)