This experiment allows to display a video stream from a standard
web-cam on the BioWall. Colors are mapped into eight color-levels
(between green and red) to be compatible with the BioWall's LEDs.
The BioWall's cellular tissue has not been designed specifically to
be used as a video display. It is however possible to
display digital images and even video streams in low resolution and
at low frame rates by means a rather sophisticated design.
experiment allows to display a video stream coming from a standard
web-cam on the BioWall. We use a Logitech camera with an image resolution
of 160x120 pixels and 32 bits of color information. The captured video-stream
is pre-processed on a PC before a special bit-stream is sent to the BioWall.
The pre-processing basically consists in:
- Cutting and scaling the image
to the BioWall's resolution (100x320 pixels). The video-stream is
actually displayed twice (side by side) on the BioWall.
colors to eight color-levels (between green and red) by means of the
To display the video bit-stream, the
BioWall's molecules are configured to form a large shift-register.
The bit-stream is decoded within each molecule and the information
received is displayed. The actual frame-rate is about one image per
In addition, a three-image animation with a much higher frame-rate
can be generated on the BioWall itself: by touching one of the touch-sensitive
membranes, the current image is memorized in a special memory located
within each molecule. When all available memories are full, the three
images are displayed in an infinite loop (at about 8 frames per second).
For further information
- R. W. Floyd and L. Steinberg. "An adaptive algorithm for
spatial greyscale". Proceedings of the Society of Information
Display, 17(2):75-77, 1976.