© 2001 jukal at cyberian dot org
Imaginary data transfer - forget bluetooth.
Transferring arbitrary data wirelessly as an imagestream from your PC to handheld. What?

In today's series of Amazon Discoveries (the series that did not exist yesterday), cyberian.org is proud to represent high-speed-imaginary data transfer - a robust and obvious replacement for the bluetooth techonology. ;)  
Assume that we have:
  1. A display, with 60Hz screen refresh rate at 1800*1440, I have Sony CPD-E400
  2. A digital camera, capable of taking 20 frames per second at 640x480 pixels. Take the rather cheap Digital Ixus 300 from Canon for example.
  3. A handheld. Let's take Compaq Ipaq it looks nice and you can run Linux on it.
  4. Efficient and reliable way for packing data in images. Take MaxiCode. Capable of storing 100 characters per square inch. Requires 200 dot per inch resolution. Data is usable even if 25% of image is destroyed. It's like an enhanced version of barcodes.
Ok. Off we go Snoopy...
 
Now, what I really would like to do is to transfer a portion of Hitchhiker's Guide to the Galaxy from my PC to my Handheld. Let's begin with the first 100 000 bytes.
 
So, I quess we need to write a MaxiCode encoder. As MaxiCode is a public domain symbology, the specifications are available from AIMI - no problem. *code code code*. So there, we wrote one.
 
Then, what we need to do is to write a software to flow the maxicode sequence on display *code code code*. Everyone ready yet?
 
At this stage, we have got 1000 maxicode images, and the software needed to display the images on screen at 1800x1440 resolution, 20 frames per second. But hey! The digital camera takes pictures at a lousy 640x480 resolution, let's adjust our software so that it sends each image twice - reduced speed but increased result in quality. So damn, as result we are like back to 10 frames per second or something.

Let's say that we are humble and only display 32 MaxiCode images per frame in our first set-up. So. What we are now capable of doing is to display 320 maxicode images per second. I quess that makes 32000 bytes per second.
 
Then we realize, that we have no way of receiving this data. So we attach our digital camera to the Handheld and write software for it *code code code*. This software needs to help the user to focus the camera to the PC display, catch the maxicode sequence in realtime and decode the data back to it's natural form: Hitchikers guide. Simple.
 
So, everything is done. Now, at this point we sit back in our ergonomic chairs and prepare the set up. Camera! Action! Floooooooooosh. In 3.125 seconds of hallusinating imageshow we transferred the data. It was quite enjoyable and - for sure - mind-treating.
 
Enjoy reading :)
 
So, at this point all you nerds out there are implementing this, let me know how it worked ;)
 
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Copyright © 3/Sep/2001 Jussi Kallioniemi [ jukal at cyberian.org ]
The oddities presented here (that are not copyrighted or patented by someone else, ofcourse) are released under the GNU Free Documentation License.
 
 
Cyborg in ear: "nice orgy bar".
"Bingo!", Ear cry.