Re: [Gimp-print-devel] Calculating actual Ink amounts from CMYK pipeline

[Walker B. <fo...@wa...>]

Thanks, 

I will twiddle knobs when I have the time and see if I can back myself into clarity.

warmest
-Walker



> On Jul 9, 2024, at 8:41 PM, Solomon Peachy <pi...@sh...> wrote:
> 
> On Mon, Jul 01, 2024 at 03:00:49PM -0400, Walker Blackwell wrote:
>> I can follow 60% of this . . .
> 
> When it comes to this stuff, I feel like the one-eyed king leading the 
> blind.  :(
> 
>> If I were to force it to print the basic CMYK percentages (basically 
>> nix all the GCR combo stuff and print 40% black if that is what the 
>> pixel has for its K value no matter what)
>> 
>> I see that I can just say output[0] = k;
>> 
>> But I don’t follow the logic of ck * cg.
> 
> I _think_ what happens here is that it works out the common K between 
> the channels, then uses a (non-linear) lookup table (and the color 
> balance knobs) to figure the corresponding amount to reduce each channel 
> by.
> 
>> Maybe ideally I’m simply saying for the color outputs that it’s 1 * 
>> cg->color_balance. ?
> 
> That sounds logical, but I've never sufficiently immersed myself in 
> gutenprint's core color channel stuff to truly understand it, and I'm 
> embarassed to say I've probably forogotten 89.3% of what I managed to 
> absorb the last time around.
> 
> - Solomon
> -- 
> Solomon Peachy			      pizza at shaftnet dot org (email&xmpp)
>                                      @pizza:shaftnet dot org   (matrix)
> Dowling Park, FL                      speachy (libera.chat)