Re: [PLUG] which image transfer format?

[Bob Schwier <schwepes@netaxs.com>]

I could bore you with the math.  I have the book I used in college about a
meter away.  Anyway, Jeff is right, degregation is inevitable but until it
gets massive you will not notice.  In video, your eyes will fill in the
necessary information, in audio which is what I learned your ears will
fill in.  Consider that when you listen to an AM radio station, you only
hear one fourth of the sound because the rectification is only of what is
on the upswing of the positive side of the carrier wave.
Don't most compression formulations use the fact that there will be series
of ones or zeros that can then be said to be zero sixteen space instead of
writing 0000000000000000?  That should be replicatable as the short hand
does not remove any information until the dread bit error rate grabs you.
bs


On Fri, 18 Oct 2002, Jeff Abrahamson wrote:

> On Fri, Oct 18, 2002 at 08:13:39AM -0400, Kevin Brosius wrote:
> > Jeff Abrahamson wrote:
> > > 
> > > On Tue, Oct 15, 2002 at 03:41:18PM -0400, Jeff Weisberg wrote:
> > > > [2] the real world is not 24 bit color
> > > 
> > > Actually, neither is your digital camera, unless maybe it's extremely
> > > high end. Most digital cameras have eight bit CCD's with color masks
> > > over them, so, essentially, one pixel is 8 bit red, the next 8 bit
> > > green, the next 8 bit blue, repeat. (In practice, it may use a
> > > different color space, and so forth.)
> > 
> > Umm... In computer graphics, 24 bit color is considered 8 bits for each
> > of RGB, right?  What am I missing here?
> > 
> > Oh, I see, you're referring to the practice of only storing one color
> > plane _per_ pixel on digital cameras.  That doesn't really make them 8
> > bit color cameras though.  They still have 24 bits of color depth.  Just
> > 1/3 the resolution (width x height), right?
> 
> Well, the image you get from your camera has eight bit color depth
> because of the interpolation. (Try "identify" on one.)
> 
> I'm not sure if what you say is equivalent, I haven't studied enough
> information theory. But I think essentially that information is lost
> in the interpolation, so you can't actually recover a 24 bit image,
> even at 1/3 (1/9) resolution.
> 
> -- 
>  Jeff
> 
>  Jeff Abrahamson  <http://www.purple.com/jeff/>
> 
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