[Lcms-user] Re: TIFFICC

[<ma...@li...>]

Hi,

>   How difficult would it be to adapt this to Greyscale images using a
> "grey-only" colorspace ICC profile?

Grayscale on input is already supported, just use /i<grayprofile>.
However, only PHOTOMETRIC_MINISBLACK files will
be correctly translated.PHOTOMETRIC_MINISWHITE will
be reversed.

On output, unfortunately, TIFFICC doesn't work. This is
because lcms (at least in its 1.07 incarnation) doesn't support
gray profiles for output.

The difficulty resides in the way the CMM should interpret a
transform between RGB (or CMYK) and a gray profile...
Should give Y? Luminance? and how relates this with
white/black points?

We are working on this, and expect rev 1.08 will support
output grayscale profiles, and reversed components as well.

If you only need gray to gray, I can send preliminar sources that
does this translation. If you want to extract grayscale information
of a color image ... well, this will take a couple of months.

Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...


----- Original Message -----
From: "Borden, Brian" <bri...@ve...>
To: <in...@li...>
Sent: Thursday, June 21, 2001 1:24 PM
Subject: TIFFICC


>
>   This is an excellent piece of work.   This will save me many hours of
> manual CMYK TIFF conversions.
>
>   We noticed that TIFFICC accepts only RGB, CMY, CMYK, and Lab.  This
raises
> a new question:
>
>   How difficult would it be to adapt this to Greyscale images using a
> "grey-only" colorspace ICC profile?
>
>
> Brian Borden
> Verizon Directories Corp.
> Verizon Place
> DFW Airport, TX 75261
> (972) 453-7628
>
>