Invisible White Board for Video Presentations
<![CDATA[This projects allows a presenter in front of a web camera to write in
the air as if he was writing on a white board. This assumes the
presenter can view himself on a screen so he can see what he is writing.
Currently when a presenter turns around to write on a real white board,
focus leaves the audience. I theorize it will improve learning when the
students/audience is continously engaged by the presenter even when
writing notes and diagrams.
The application allows the presenter
to save and clear the board. It is also a single
camera solution and that uses the built-in webcam available on most
computers.
The initial prototype requires a bright LED pen with a finger
activated ON/OFF switch. When the LED is ON you are writing and when it
is OFF you are not. But alternatively you could just have a colored
marker on the tip of your finger that you expose to write and conceal
to stop writing.
The prototype software is written in Adobe AIR with an invisible
background. The AIR application is constantly performing a screen
capture of the webcam. It then processes the image and strips off
everything that does not satisfy the color threshold of the LED. The
LED color is then converted to bitmap data with the same color and
position as the original LED. The bitmap is then overlayed as a
transparent PNG that is placed in the AIR app. This assumes the App is
on-top of the presenters web cam image. In the end the app accumulates
all the LED light drawn in front of the camera and shows it on the
screen. The App has a menu that allows you to clear the screen and I am
adding a save, back, and forward option.
Currently the project has the following issues. First, it is too
slow -- resulting in gaps in some of the writing. Second, it just
shows the writing on the presenters screen (making it currently useless
to the audience). I am working on Adobe AIR code that allows me to
overlay the PNG on the outgoing webcam stream.
I will likely post a Youtube video soon. ]]>
See also
