hi Carl,

In the visual effects world (from which image magic is a spin-off of earlier
work) we talk in bits per  *channel*  meaning each channel or layer of
data.  in rgb images this means 8 bits * 3 channels (+ alpha if any) thus 24
or 32 bits per pixel.

the human eye can see more variations of darkness than light, so at 8 bits,
we see colour banding... this led to 12 bit displays (actual 12 bit DACS) ,
10 bit log space encoding (usually saved as cineon, with lookup table
support) and simpler but bigger sized 16 bits per channel images.

the 16 bits per channel means you can do a lot of math on the image pixels
which invariably adds artifacts, before image degradation is visible to the
human eye.

internally, image magic also does float images, where each pixel is encoded
in float values so can basically scale to order of magnitudes and thus
support HDRI images... but the stand alones do not support it IIRC... only
the DLL calls and libs themselves.

IIRC image magic can go up to 128 bits per channel (for each pixel) in float
space, but I see no real world application for this.  this means a video
image (NTSC) is over 7 MB in size, instead of ~1MB !


-MAx

On 7/6/07, Carl Read <[EMAIL PROTECTED]> wrote:
>
>
> Hmmm - thanks.  Though for the Windows versions they're talking about 8
> and 16 bits-per-pixel.  See...
>
> http://www.imagemagick.org/script/binary-releases.php#windows
>
> Surely they don't mean image depths!?  More likely processor speed,
> hopefully?
>
> -- Carl Read.
>
>
> On Friday, 6-July-2007 at 16:30:23 Maxim Olivier-Adlhoch wrote,
>
> >image magik. there even is a rebol integration on rebol.org.
> >
> >-MAx
> >
> >On 7/3/07, Carl Read <[EMAIL PROTECTED]> wrote:
> >>
> >>
> >> Many thanks - that's nice to know.
> >>
> >> And is it too much too hope for that there's a cross-platform solution
> to
> >> View's inability to save images as JPEGs?
> >>
> >> -- Carl Read.
> >>
> >>
> >> On Tuesday, 3-July-2007 at 9:12:18 =?ISO-8859-1?Q?fran=E7ois_jouen?=
> >> wrote,
> >>
> >> >Hi Carl
> >> >I'm using rebol/view on Mac Intel: no specific problem for this
> >> >plateform
> >> >Le 2 juil. 07 à 23:34, Carl Read a écrit :
> >> >
> >> >>
> >> >> The REBOL/View beta for the Mac is advertised as for PPC based
> >> >> Macs.  Does this mean it won't run on x86 based Macs?
> >> >>
> >> >> -- Carl Read.
>
> --
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