Bagtrees: Software + Hardware Prototype

4:45 PM in General by Adityo Pratomo

As an addition to Susanne’s previous blog post, this post will describe our prototype from a technical point of view.

As an alpha version prototype we try wo achieve these things:

1. Display a person in front of the screen and replace his/her head with a plastic bag animation. This will happen as long as the person stands still.

2. Remove the plastic bag and the person’s head when he/she moves to a certain amount, eventhough the plastic bag will still follow the person’s head

3. That action in number 2 will also change the LED color, where those LEDs are located somewhere else outside the screen.

To achieve those goals, these are the steps we did

1. Detect the person face using OpenCV’s face detection in Processing.

2. Use the Processing’s gifanimation library to display the transparent gif made from 3D model that Johnny created using 3DS Max. This animation replaces the person’s face.

3. Do some frame differencing to count the number of movement, set the threshold of movement’s to trigger both the head removal function and the LED’s changing color.

4. To do the head removal, a background copy is done to simply replace the face of the person, creating the illusion of a head disappearing.

5. To change the LED color, Processing is made to communicate with the Arduino board through the Firmata firmware. Since we’re using an RGB LED, then the LED color can simply changed by assigning different voltage value for the Arduino’s port where the LED’s pins are connected.

So far, we have managed to completed these tasks. As a prototype, this will act as a framework for our final artwork, where some more animation and more LEDs will be involved.

These are some screenshots from the video demo that I did last night

video will talk more than images, so you may want to check the video on my website here