Re: [Lcms-user] Confused about cmsCreateMultiprofileTransform error

[Steve M. <sm...@mu...>]

On May 8, 2008, at 19:15:12, Alastair M. Robinson wrote:

> Well, reading the API documentation for
> cmsCreateMultiprofileTransform(), I see:
>     - Colorspaces must be paired with the exception of
>       Lab/XYZ, that can be interchanged.
> So I guess that means you can't directly create an RGB -> CMYK (- 
> >CMYK)
> -> RGB transform with this function.

The api comment didn't make any sense to me. Paired how? (rhetorical)

> What you probably could do is create the individual stages of your
> transform with cmsCreateTransform(), convert these transforms to
> DeviceLinks with cmsTransform2DeviceLink(), and then chain the
> devicelinks together using cmsCreateMultiprofileTransform().
>
> In practice, you're prebably better off using this only for the case
> where you need four profiles - and using cmsCreateTransform when you
> have two, and cmsCreateProofingTransform() when you have three.


I'll give that a shot. Seems like a lot of work and a lot of extra  
objects to keep track of and delete. ColorSync's CWConcatColorWorld is  
a much more elegant model. I'll submit a suggestion that lcms also get  
similar functionality added.

_________________________________________________________
Steve Mills                              Me: 952-401-6255
Senior Software Architect                         MultiAd
sm...@mu...                       www.multi-ad.com