Re: [Lcms-user] ICC Monochrome Input Profile and alpha

[Aaron B. <bo...@gm...>]

Noel,Marco,

Thanks! I understand - no gamma applied to alpha channel.

Cheers,
Aaron


On Mon, Feb 27, 2017 at 10:01 AM, Noel Carboni <
NCa...@pr...> wrote:

> Hi Aaron,
>
>
>
> As far as I know, an alpha channel (transparency) is considered linear and
> not subject to profile-based transformation.  That says it should be
> perfectly valid to have one - or not - in a profile-tagged image.
>
>
>
> Not long ago Marti added the ability for LittleCMS to preserve extra
> channel values as a transform is done by Little CMS (e.g. for passing alpha
> channel data through unchanged).  That reduced the application code needed
> to handle RGBA and GA data if transforms are not done in place (i.e., from
> one buffer to another).
>
>
>
> -Noel
>
>
>
> *From:* Aaron Boxer [mailto:bo...@gm...]
> *Sent:* Mon, February 27, 2017 9:33 AM
> *To:* lcm...@li...
> *Subject:* [Lcms-user] ICC Monochrome Input Profile and alpha
>
>
>
> Not directly related to lcms, but I have a question about the Monochrome
> Input Profile:
>
> is it valid to have an image with this profile, and to also have an alpha
> channel ?
>
> Thanks,
>
> Aaron
>
>
>