[Lcms-user] Re: lcms

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

Hi,

> I think what I would like to do is build some type of profile that=20
> describes the BBitmap class.  Mabey just assume the Gamma and white=20
> point values (educated gess :P)

Yep. Then, virtual profile is just what you need. You still need =
primaries,=20
so Rec709 would be fine as default.

> My main goal is monitor profile (which I assume can be made similar to =

> the Create_sRGB_Profile() but use a User Set Gamma and whitePoint)

Yes, you can also use virtual profile for this. And with Rev 1.07  you =
can also
save this into an .icm file. Using virtual profiles on both sides of =
transform does
speed up a lot the transform times.=20

For saving a virtual profile into a .icm file, just use=20

  _cmsSaveProfile(cmsHPROFILE hProfile, const char* FileName)

You can also use that ones for adding information before saving

       _cmsAddTextTag(hProfile, icSigProfileDescriptionTag, =
Description);
       _cmsAddTextTag(hProfile, icSigCopyrightTag, Copyright);
       _cmsAddTextTag(hProfile, icSigDeviceMfgDescTag, Manufacturer);
       _cmsAddTextTag(hProfile, icSigDeviceModelDescTag, Model);

The hProfile is the handle you have created with cmsCreateRGBProfile()
Those funtions are new in 1.07, and experimental. Hence the "_" at =
begining.
But are working fine to me right now.=20

> How do I tell the profile about the bit ordering.

You have predefined descriptors for specify the type. For example

TYPE_RGB_8 : This is RGB of 8 bits per component
TYPE_RGBA_8: This is RGB of 8 bits per component, plus alpha

Note that the transform can be used to convert between formats, i.e., I =
can give
TYPE_BGR_16 (48 bits, swapped B, R) on input and TYPE_RGB_8 on output,
and the CMM will translate between formats as well. There are a LOT of =
formats, see
the tutorial for a list of supported ones.

About the file endianess, don't worry, lcms does handle it =
transparently. All=20
icc profiles are stored in big endian notation. Here your swab() is =
important ;)


> Oh, and no problem posting to the list .. .I was thinking about =
joining=20
> it.   Still looking at differant CMSs though someone droped me a link =
to=20
> Argyll today .. gess I should at least check it out :)

Yep, the nice thing is you can use icc profiles generated by Argyll with
lcms, Graeme's code is more on profile generation side, while lcms is=20
more on transformation speed.

Regards,
Mart=ED.

----- Original Message -----=20
From: "YNOP" <jt...@en...>
To: <ma...@li...>
Sent: Friday, May 18, 2001 9:13 PM
Subject: Re: lcms=20


> I think what I would like to do is build some type of profile that=20
> describes the BBitmap class.  Mabey just assume the Gamma and white=20
> point values (educated gess :P)
>=20
> My main goal is monitor profile (which I assume can be made similar to =

> the Create_sRGB_Profile() but use a User Set Gamma and whitePoint)
>=20
>  /* linear color space (little endian is the default) */=20
>         B_RGB32 =3D                       0x0008, /* B[7:0]  G[7:0] =20
> R[7:0]  -[7:0]                                       */=20
>         B_RGBA32 =3D                      0x2008, /* B[7:0]  G[7:0] =20
> R[7:0]  A[7:0] =20
>=20
> Here is the dev for the color space that BBitmap class uses.  How =
would=20
> i go about building a Profile now that I have this data.  How do I =
tell=20
> the profile about the bit ordering.
>=20
> Oh, and no problem posting to the list .. .I was thinking about =
joining=20
> it.   Still looking at differant CMSs though someone droped me a link =
to=20
> Argyll today .. gess I should at least check it out :)
>=20
> Thanks again for all your help and takeing time out to answer =
questions
>=20
>=20
> YNOP=20
> yn...@ac...
> http://www.?.com
> ----------------------------------------------------------
> Too much, too easy, it's lethal.  Some, not too easy, the parasite is=20
> tolerated.
> -  Jean-Louis Gassee, Be, Inc.=20
>=20
>=20
> -----------------------------------
> This message was sent with the demo version of Postmaster, a BeOS mail =
client.
> For more information, please visit http://kennyc.com/postmaster
>=20
>=20
>=20