Re: RIMM/ROMM and ProPhoto
Re: RIMM/ROMM and ProPhoto
- Subject: Re: RIMM/ROMM and ProPhoto
- From: Chris Cox <email@hidden>
- Date: Sat, 04 Nov 2006 16:03:16 -0800
- Thread-topic: RIMM/ROMM and ProPhoto
The version 4 versus version 2 explains the differences you're seeing.
The ProPhoto profile was created earlier because the version 4 specification
did not exist when ROMM was renamed ProPhoto for mass consumption. ROMM and
ProPhoto are still the same, but the interpretation of the profile versions
differs slightly.
Actually, Adobe uses the ProPhoto V2 profile internally in ACR.
ProPhoto is not outdated, it's just a V2 profile.
You're making a big mountain out of a rather tiny molehill here.
Chris
On 11/4/06 2:21 PM, "Richard Wagner" <email@hidden> wrote:
>
> On Nov 4, 2006, Chris Cox wrote:
>
>>> I've had trouble tracking down the significance of the differences
>>> between ROMM RGB and ProPhoto RGB.
>>>
>>
>> I don't know which specific profiles you're looking at - but
>> ProPhoto really
>> is ROMM with a more user friendly name. And ROMM is normally just a
>> matrix/TRC profile (that was part of their design goals), so I
>> don't know
>> how it could have all 3 rendering intents.
>>
>> Chris
>
> Chris,
>
> In Photoshop, make a new document, using ROMM-RGB as the profile.
> Save it, embedding the profile. Extract the profile with the utility
> of your choice. It is not the same as a ProPhoto profile extracted
> in the same manner, as output from ACR - and it is not just the name
> that's different. Some of this (e.g., the media white point and
> black point differences) was confirmed earlier on this List. Plot
> them both (esp. in Luv or Yxy) and these differences are apparent.
>
> The ROMM-RGB profile is "Copyright 2002 Adobe
> Systems Incorporated"
> The ProPhoto profile is Copyright (c) Eastman Kodak Company, 1999,
> all rights reserved.desc
>
> ROMM-RGB has a device type of "Print," whereas ProPhoto has a device
> type of "Monitor."
> ROMM-RGB has a creation date of 2002/10/15, compared to 1998/12/1 in
> ProPhoto.
>
> ROMM-RGB is an ICC Version 4.0.0 profile.
> ProPhoto is an ICC Version 2.1.0 profile.
>
> There are A2B0, A2B1, A2B2, B2A0, B2A1, and B2A2 tags corresponding
> to RGB->XYZ LUTs for Perceptual, Colorimetric, and Saturation in ROMM-
> RGB. This is very much unlike ProPhoto, which has r, g, b TRC's and
> XYZ colorant values. The curves for AbsCol, RelCol, and Perceptual
> are different from each other in ROMM-RGB, unlike ProPhoto.
>
> If ProPhoto simply has a "more user friendly" name, why all the
> differences? And why the creation date years before ROMM-RGB? And why
> different ICC versions? And why does Adobe bother to install ROMM-RGB
> internally with Photoshop?
>
> As Adobe apparently uses ROMM-RGB internally in Photoshop/ACR (that's
> where the profile is installed), I'm wondering why Adobe chose to use
> the seemingly outdated ProPhoto profile as output from ACR, rather
> than what appears to be a more modern, and more useful, and more
> appropriate ROMM-RGB. Surely photographers and others could adapt to
> a name change...
>
> Thanks,
>
> -Rich Wagner
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