QTR-Quadtone RIP

Roy,

Just so I understand what's going on better, are you dithering when you go
from 16bit to 8bit?

Txs,

Mike

2008/12/28 Roy Harrington <roy@harrington.com>

> Hi Mike,
>
> I will probably do 16-bit as some point.  But I really don't think it will
> make much difference.  All the ICC internals are already 16-bit and if you
> have a 16-bit input file all the profile processing is already done in
> 16-bit.
> The downsizing to 8-bit is done as the last step and its basically just
> dithering the output in two stages -- 16 to 8 bit and then 8 to printer
> data.
>
> Roy
>
> On Sun, Dec 28, 2008 at 9:35 AM, mrmrking <drmrking@...> wrote:
> > Hi Roy,
> >
> > Do you plan to support 16 bit printing with QTR?
> >
> > 16 bit printing will allow us to use an ICC profile based workflow
> > without losing maybe 5 - 10% of 8 bit tonal values in the conversion
> > to print profile.
> >
> > What I mean by this is that currently when you print with an ICC
> > profile the conversion of a 16 bit image in working profile space to
> > 8 bit image in print profile space, rounds up or down about 5 - 10%
> > of the values, so you lose about 5 � 10% of 8 bit tonal values in the
> > conversion. You can see this by just taking an 8 bit target (0-255)
> > and converting it to the print profile and seeing what values from 0 �
> >  255 you have left after conversion.
> >
> > If we could print the 16bit image this rounding up or down would
> > happen at much higher tonal values, beyond anything that is possibly
> > visible.
> >
> > Epson has released 16 bit drivers on Leopard 10.5  for most of its
> > printers. Windows also now has a 16 bit printing path on XP and Vista
> > (no Epson drivers as yet).
> >
> > I hope we can have 16bit printing support in QTR.
> >
> > Txs,
> >
> > Mike
> >
> >
> >
> >
> >
> >
> >
> >
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