Re: pixelvision concept

["Brent Buescher, Jr." <buesch@snake.srv.net>]

>>>>> "Alexander" == Alexander the Great <kanaris@bode.usc.edu> writes:



    Alexander> It sure does, otherwise it wouldn't be possible to pack

    Alexander> so many pixels (something like 128*96) at 8 bits of

    Alexander> resolution!!  It is probably only 5 or 6 :-)



It could easily be as few as 4.  Pixelvision imagery looks strikingly

similar to (but finer than) the 2-bit (four level) 160x200 stills I

can take with my computereyes "frame grabber" on my Atari 800XL.



Come to think of it, a pixelizing frame grabber for PCs would be an

even better toy than a "pixel box".



    Alexander> The encoding uses both the frequency and amplitude

    Alexander> space, probably something like Trellis coding, if you

    Alexander> know what I'm talking about.



Never seen Trellis coding, and the nearest DSP text to me doesn't

mention it.  Is it an analog signal compression technique?



    Alexander> You can pack about 8-10 bits in each audio cassette

    Alexander> "sample".  (Based on the typical SNR figures). Don't

    Alexander> think about the encoding as purely "digital", i.e. only

    Alexander> 1s and 0s.



Is the encoding of pixelvision digital or analog?  



Brent