QTR-Quadtone RIP

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

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@gmail.com> 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
>
>
>
>
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

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
> >
> >
> >
> >
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>


[Non-text portions of this message have been removed]

On the Mac its done by Photoshop (or the print system), on the PC yes I
dither in the conversion of 16bit tiff files.

Roy

On Sun, Dec 28, 2008 at 10:18 AM, Michael King <drmrking@...> wrote:
> 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@...>
>
>> 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
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > ------------------------------------
>> >
>> > Yahoo! Groups Links
>> >
>> >
>> >
>> >
>>
>> ------------------------------------
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>
>
> [Non-text portions of this message have been removed]
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>