QTR-Quadtone RIP

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
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
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