livecode changes image colors without being asked to do it

[Bob Sneidar]

Not only that, but a PDF can have embedded objects, each with their own ICC profile. For instance, a logo should be using a saturation intent and absolute colorimetric profile to make sure the color remains constant. Think Home Depot Orange. A photograph however might need perceptual intent with relative colorimetric. 

A high end print controller like a Fiery or Creo can honor these embedded profiles to give you just the right output that you expect. Livecode should be able to print these kinds of PDFs because it's the pint controller that handles the RIP. I would not expect LC to be able to CREATE these PDFs however. 

Bob S


> On Aug 31, 2017, at 04:36 , Keith Martin via use-livecode <use-livecode at lists.runrev.com> wrote:
> 
> On 30 Aug 2017, at 15:31, Robert Brenstein via use-livecode wrote:
> 
>> The stack is used to produce a PDF file and the printing shop requested CMYK
> 
> A slight aside – please forgive me.
> 
> I teach publishing and have worked in the print industry (among others) since the 1980s. It's now the norm for printers to accept PDFs with embedded RGB images and do the colour conversion to CMYK in the final RIP stage as it's printed. This means that the actual conversion is done with settings that are most appropriate to the actual print method and device, not a generic 'make it CMYK' process. I've seen print projects go expensively wrong because of inappropriate CMYK conversion settings.
> 
> This is often known as an RGB workflow – although 'Hybrid workflow' is more accurate, as it's just imported images that are left in their native colour model; colour swatches should still be specified using the colour model of the intended output process.
> 
> Having said this, the bottom line is always "ask your printer and follow their advice," not least because if something goes wrong with the colour repro they can't blame you. ;)
> 
> k
> 
> ---
> 
> Keith Martin
> Senior Lecturer, LCC (University of the Arts London)
> President, http://IVRPA.org
> http://PanoramaPhotographer.com
> http://thatkeith.com
> +44 (0)7909541365