[argyllcms] Re: [argyllcms] Re: Printtarg dithering for TIFF output request
- From: Nikolay Pokhilchenko <nikolay_po@xxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Sat, 07 Apr 2012 15:26:14 +0400
Graeme Gill wrote:
Nikolay Pokhilchenko wrote:
> 1) generating the target data with preliminary (from similar device)
> ICC-profile; 2) generating
> 16-bit TIFF target images; 3) changing the "color depth" of images from
> 16-bit to 8-bit in Adobe
> Photoshop Elements (the dithering is applying in Photoshop by default); 4)
> saving 8 bit per
> channel targets.
Hi Nikolay,
such a thing is certainly possible, and I have some well developed stochastic
fixed
pattern dither code that could be applied to the task, but I guess I'm a little
puzzled
by the work flow :- normally in color management you strive to keep the
profiling and
final used workflows as close as possible, so the question is why the profiling
workflow
is 8 bit, while the printing workflow is 8 bit dithered ? What is doing the
dithering
for the normal printing workflow ? Why can't the 16 bit test chart be printed
via
that workflow ?
Well, it's a good question. I didn't want to explain to the end users why I ask
them to print 16-bit targets when they prints 8-bit images in general. I want
building a good profiles with the user's habitual image bit-depth. The end user
can disable dithering by mistake. And if I send him 16-bit target files, it
would be impossible to characterize ink mixtures between quantization levels.
On the contrary, while printing at high printer resolutions with dithering, the
intermittent ink quantities can be characterized easily without 16-bit test
charts and without dithering at the user side.
It will be simpler to ask the user to enable dithering if the problem will
arise after profiling nor explain them how to print 16-bit targets correctly
and where to check the dithering settings in his application before target
printing.
So, I'm preferring to keep the dithering under my control, not at the user
side. It saves the time both mine and the client.
Other related posts:
- » [argyllcms] Re: [argyllcms] Re: Printtarg dithering for TIFF output request - Nikolay Pokhilchenko
