Re: [9fans] PNG and APE (cntd)

["Jack Johnson" <knapjack@gmail.com>]

On 4/27/06, Charles Forsyth <forsyth@terzarima.net> wrote:
> > And, BTW, PNG allows 16-bit per colour, a 48-bit depth per pixel.
> > Thanks to libpng, my "npng" can render these as 24-bit images.
>
> ``the human ear can't hear as high as that / still, it ought to please any passing bat''

I used to do some image fiddling a long time ago (image prep -> TGA
for television), and came across some info regarding medical x-ray
photographs being stored in a 12-bit grayscale format.  It's likely
that so fine a variation is either above or right on the edge of human
perception (given current working environments), but one
counterargument is that maybe it's not a human looking at the data.

Plus, I think 12 bits per color would be right around the limit of
film, something like a 4000:1 contrast ratio, so depending on the
scanner you'd likely be pushing the limits of the original medium
anyway, "lossless" transfer from analog to digital, whether or not
you're in a good position to make use of the data.

Archaeologists have the same problem all the time, looking at data
gathered by previous scientists and realizing the original gatherers
didn't save enough information for the current questions, so now they
tend to swing the opposite direction and record all the minutiae so
that years later someone can glean new information from an old dig.

One day, you may be a bat.

-Jack