Re: Which scanners REALLY provide 36 bit output? HP?

From: Marko Cebokli (
Date: Tue Dec 12 2000 - 08:29:49 PST

  • Next message: Ian Stirling: "Re: Which scanners REALLY provide 36 bit output? HP?"

    Bob Washburne wrote:
    > Stephen Williams wrote:
    > >
    > > Imagine if hearing could be similarly tricked using only three pitches:-)
    > >
    > I think it already has been.
    > There was a game (Barbie ?) for the old Commodoore 64 in which Ken calls
    > Barbie up for a date and she has to go shopping for a new outfit.
    > Anyway, Ken and Barbie both had nice digitised voices. Beachhead II
    > also had good voice digitization.
    > But the only sound available for the C64 was a simple synthesizer which
    > produced square, triangle, sawtooth and noise. These were combined very
    > nicely (the audio equivilent of RGB) to reproduce recorded speach.
    > That what you mean?
    > Bob Washburne


    That was done using PWM, a time-domain technique.
    You can't do it in frequency domain, because the ear is a several 1000
    channel analyzer versus 3 channels of the eye. (Yes, it's 3 - the
    luminance sensors (the 'rods') have the same sensitivity as the 'green'
    channel 'cones')

    Back to scanning - if you need to get all the info that is in a
    photograph ABOUT THE ORIGINAL SCENE, a three channel scanner is enough,
    because the original photo process has already reduced it to 3 chans.
    By using a multispectral scanner, you'll only get more info about the
    spectral shapes of the pigments (dyes) that make up the photo.

    But I suspect that those 19th century photos are single-channel anyway?

    Marko Cebokli

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