Pages: 1 2 [3] 4 5 ... 35   Go Down

### AuthorTopic: attention color whizes: non-typical sRGB/RGB/ProPhoto question  (Read 239405 times)

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #40 on: January 02, 2011, 10:31:18 am »

Right, and you can select the blue primary independently from the red. When you do that you create a new colorspace.

No new color space at all. Repeat: no new color space at all. Just a new co-ordinate system in the same space. I don't think you have looked at my diagram where I show Adobe RGB and ProPhoto RGB primaries. There are two cooridanate systems shown there, viz., Adobe and Prophoto, but the space is the same.

Quote
If they are two different coordinate systems, they are two different color spaces.

Again you are repeating what I just answered above. Color space is the same. There are more than one coordinates systems in the same space. Oh come on, in computer graphics they do it all of time with rotation of the axis. Does that give a different space. Not at all. Just a different frame of reference for coordinate system. If you don't understand this fundamental fact then you are not following the inherent principles of colorimetry.

Quote
Another thing, in all this discussion we have not seen a transformation matrix from joofaSpace to XYZ. The matrix you would like to use—the D50 matrix we've been using above, does not actually share the primaries from AdobeRGB. You can very easily calculate the chromaticity coordinate of the primaries from the matrix. If you do this for the AdobeRGB D65 matrix you get these coordinates (exactly what they should be):
Red:  0.6400 0.3300
Green:  0.2100 0.7100
Blue:  0.1500 0.0600

If you do it for the D50 matrix you get:
Red:  0.6484 0.3309
Green:  0.2301 0.7016
Blue:  0.1559 0.0660

They're significantly different. So if your goal is to use a transformation matrix with the same primaries as AdobeRGB but with a different white point, you're using the wrong one. Like I posted above, that isn't what that matrix does.

Remember, didn't I inform you that you are using an approximate matrix for transformation in an Adobe RGB (D50), because you multiplied a Adobe RGB (D65) matrix with Bradform transform, which is not exact. You can calculate the exact matrix directly. I will give you the coordinates of the blue primary in Adobe RGB (D50), and they are [0.137826   0.055130   0.725885] (compare to yours of [0.14922403  0.06321976  0.74483862]), where as the coordinates of the Adobe RGB (D65) blue primary are [0.188185   0.075274   0.991108]. And see below:

x,y chromacity coordinates for Adobe RGB (D65) blue primary
[0.188185   0.075274   0.991108]/sum([[0.188185   0.075274   0.991108]] = [0.150000   0.060000   0.790000]

x,y chromacity coordinates for Adobe RGB (D50) blue primary
[0.137826   0.055130   0.725885]/sum([0.137826   0.055130   0.725885]) = [0.150000   0.059999   0.790001]

They look the same to me!

Quote
Just don't call it AdobeRGB 1998.

I don't think that you are reading carefully. I have tried not to use the words "Adobe RGB" alone. I  have always tried to use with a white point, say "Adobe RGB (D65)" or "Adobe RGB (D50)" to emphasize that both use the same primaries but the white points are different. I hope you understand it now. Incidently, Adobe RGB (D65) is the standardized notion, but it is no different in conception than Adobe RGB (D50).

Sincerely,

Joofa
Logged
Joofa
http://www.djjoofa.com

#### digitaldog

• Sr. Member
• Offline
• Posts: 20708
• Andrew Rodney
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #41 on: January 02, 2011, 11:43:56 am »

It is perfectly feasible to conceive an Adobe RGB space with D50 white point instead of the standarized D65 and Prophoto RGB space with a white point of D65 instead of standarized D50.

Look, you can conceive it anyway you wish, but altering the white point changes the color space definition and as I said earlier, call it JoffaRGB. You seem to want to imply that the color space known as Adobe RGB (1998), a space that is defined using three sets of values can be larger than the space we call ProPhoto RGB, again specified with existing, known and specific values. You do this by altering one set of its definitions to prove your point. But doing so changes the definition. Its no longer Adobe RGB (1998). If you want to alter values to produce a new working space that is bigger or smaller, fine. But don’t try passing it off as Adobe RGB (1998), cause its not that color space any longer.

I have two color spaces represented as Adobe RGB (1998) and ProPhoto RGB as ICC profiles. I load them in ColorThink and view the in 3D. ProPhoto RGB fully exceeds Adobe RGB (1998) in every direction and by a large margin. Further, ColorThink reports the Gamut Volume of Adobe RGB (1998) as 1,207,520 and ProPhoto RGB as 2,548,220. These are the very ICC working space profiles installed by Photoshop. Are you suggesting that ColorThink is incorrectly providing either the 3D gamut maps, the gamut volume numbers or that Adobe has provided us two profiles that don’t represent what their WP, chromaticity values and TRC Gamma, shown within Photoshop and other utilities are incorrect?
Logged
http://www.digitaldog.net/
Author "Color Management for Photographers".

#### digitaldog

• Sr. Member
• Offline
• Posts: 20708
• Andrew Rodney
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #42 on: January 02, 2011, 11:48:15 am »

This discussion is the color space equivalent of "if my aunt was a man, she'd be my uncle".

That’s wonderful and I just have to paste that into my collection of great quotes. OT but I heard one the other day on a forum which is similar:
Quote
Keke Rosberg (a Finnish Formula 1 race driver) had a great quote regarding such things: "if mother had balls she'd be the dad."
Logged
http://www.digitaldog.net/
Author "Color Management for Photographers".

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #43 on: January 02, 2011, 11:55:15 am »

Look, you can conceive it anyway you wish, but altering the white point changes the color space definition and as I said earlier, call it JoffaRGB. You seem to want to imply that the color space known as Adobe RGB (1998), a space that is defined using three sets of values can be larger than the space we call ProPhoto RGB, again specified with existing, known and specific values. You do this by altering one set of its definitions to prove your point. But doing so changes the definition. Its no longer Adobe RGB (1998). If you want to alter values to produce a new working space that is bigger or smaller, fine. But don’t try passing it off as Adobe RGB (1998), cause its not that color space any longer.

Do you have reading comprehension problem? No I am not joking. Seriously? Have you not understood that the basic premise of my argument is to find color(s) that are represented in standardized Adobe RGB (D65) but not in standardized Prophoto (D50). Where is JoofaSpace coming in these? Are these not the standard color specification of these color spaces. I only ventured into using Adobe RGB primaries with non-standard D50 to illustrate what is the notion of a "unit vector" associated with a color space. Apparently it is lost on you.

Quote
I have two color spaces represented as Adobe RGB (1998) and ProPhoto RGB as ICC profiles. I load them in ColorThink and view the in 3D. ProPhoto RGB fully exceeds Adobe RGB (1998) in every direction and by a large margin. Further, ColorThink reports the Gamut Volume of Adobe RGB (1998) as 1,207,520 and ProPhoto RGB as 2,548,220. These are the very ICC working space profiles installed by Photoshop. Are you suggesting that ColorThink is incorrectly providing either the 3D gamut maps, the gamut volume numbers or that Adobe has provided us two profiles that don’t represent what their WP, chromaticity values and TRC Gamma, shown within Photoshop and other utilities are incorrect?

I have already given you an example of color that is representable in standard (if that makes you happy) Adobe RGB (D65) but not in standard Prophoto RGB (D50). Please read the following:

http://www.luminous-landscape.com/forum/index.php?topic=49940.msg412251#msg412251

Sincerely,

Joofa
Logged
Joofa
http://www.djjoofa.com

#### digitaldog

• Sr. Member
• Offline
• Posts: 20708
• Andrew Rodney
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #44 on: January 02, 2011, 12:12:25 pm »

Do you have reading comprehension problem? No I am not joking. Seriously? Have you not understood that the basic premise of my argument is to find color(s) that are represented in standardized Adobe RGB (D65) but not in standardized Prophoto (D50).

It is you sir that has a reading comprehension problem. I’m sorry you feel that by altering a specific color space’s metrics, that you don’t understand its no longer that color space. Or that others have told you, as I have this is the case (see: But in all seriousness, Andrew is entirely correct. This discussion is the color space equivalent of "if my aunt was a man, she'd be my uncle". ProPhoto is a D50 color space.).

Quote
Where is JoofaSpace coming in these? Are these not the standard color specification of these color spaces.

Again, for the 3rd time, they are standard until you alter their DNA (their three specific sets of metrics that define them). In a quest to prove that Adobe RGB (1998) has a larger gamut than ProPhoto RGB, you resort to altering one of those specifications. Go ahead and do this using the Photoshop Custom RGB dialog after selecting Adobe RGB (1998). Change the WP. Do you see the new name? Its no longer Adobe RGB (1998). Do you wish to call it JoofaRGB? By all means do so. But you can’t call it Adobe RGB (1998) because its not Adobe RGB (1998) any more. I’m not sure why this simple point is lost on you.

Quote
I only ventured into using Adobe RGB primaries with non-standard D50 to illustrate what is the notion of a "unit vector" associated with a color space. Apparently it is lost on you.

What’s lost on you is, its no longer Adobe RGB (1998)! Call it JoffaRGB and then tell people its bigger than ProPhoto RGB if you wish.

Further, you seem to refuse to look at what every 2D and 3D gamut mapping utility proves in terms of the gamut of the two, known, standard, specifically defined working spaces represent. If you want to argue one can edit an existing color space (working space) and make its gamut larger, no one here is disagreeing with you. If you want to call this edited space the same name as the original, big argument. Its this simple fact you don’t seem to expect which is fine. There’s no reason to continue, especially if you continue to get so pissy about it.

Bruce has made this easy for you! Go here:
http://www.brucelindbloom.com/index.html?WorkingSpaceInfo.html

Go to the Gamut Viewer. Load the Adobe RGB (1998) and ProPhoto RGB. Click Update the View. Spin them. Where do you see Adobe RGB (1998) exceed ProPhoto? Note too that no where does Bruce allow you to screw around with the specifics that define these two spaces (because again, if you do, they are no longer those color spaces). Email Bruce. Ask him why he doesn’t allow you to alter Adobe RGB to make it look bigger than ProPhoto RGB. Answer, because you can’t.
« Last Edit: January 02, 2011, 12:18:33 pm by digitaldog »
Logged
http://www.digitaldog.net/
Author "Color Management for Photographers".

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #45 on: January 02, 2011, 12:20:06 pm »

What’s lost on you is, its no longer Adobe RGB (1998)! Call it JoffaRGB and then tell people its bigger than ProPhoto RGB if you wish.

Digitaldog,

Are you trying to joke? How many times I have told you that I am giving you an example of color(s) that are representable in STANDARD Adobe RGB (D65) but not in STANDARD Prophoto RGB (D50). Can I get any clearer than that. Go back and read the link I provided above.

Quote
Further, you seem to refuse to look at what every 2D and 3D gamut mapping utility proves in terms of the gamut of the two, known, standard, specifically defined working spaces represent. If you want to argue one can edit an existing color space (working space) and make its gamut larger, no one here is disagreeing with you. If you want to call this edited space the same name as the original, big argument. Its this simple fact you don’t seem to expect which is fine. There’s no reason to continue, especially if you continue to get so pissy about it.

It is pretty ironic that you don't understand some basic concepts. I am not claiming that the volume of Adobe RGB is bigger than Propphoto RGB. Just that Adobe RGB does not seem to be fully contained in Prophoto, while still apparently being smaller than ProPhoto RGB in volume.

Hope you understand that.

Joofa
Logged
Joofa
http://www.djjoofa.com

#### digitaldog

• Sr. Member
• Offline
• Posts: 20708
• Andrew Rodney
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #46 on: January 02, 2011, 12:28:52 pm »

I am not claiming that the volume of Adobe RGB is bigger than Propphoto RGB. Just that Adobe RGB does not seem to be fully contained in Prophoto, while still apparently being smaller than ProPhoto RGB in volume.

Where do you see that fact within the 3D gamut map that Bruce plots on his page?
Logged
http://www.digitaldog.net/
Author "Color Management for Photographers".

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #47 on: January 02, 2011, 12:35:39 pm »

Where do you see that fact within the 3D gamut map that Bruce plots on his page?

I shall check out what Bruce is doing? But, he is not here. So lets stick to this question that I ask you directly:

What is the representation of the color XYZ=[0.188185   0.075274   0.991108] in standard Prophoto (D50) color space?

I shall wait for an answer from you.

Joofa
Logged
Joofa
http://www.djjoofa.com

#### sandymc

• Sr. Member
• Offline
• Posts: 350
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #48 on: January 02, 2011, 12:43:45 pm »

That’s wonderful and I just have to paste that into my collection of great quotes. OT but I heard one the other day on a forum which is similar:

Keke Rosberg (a Finnish Formula 1 race driver) had a great quote regarding such things: "if mother had balls she'd be the dad."

Andrew,

Actually, that's exactly the one I was thinking of - I decided to use the "family friendly" version!!!

Regards,

Sandy
Logged

#### digitaldog

• Sr. Member
• Offline
• Posts: 20708
• Andrew Rodney
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #49 on: January 02, 2011, 12:45:08 pm »

Representation of what, calculated how? Standard Prophoto (D50) color space?
Logged
http://www.digitaldog.net/
Author "Color Management for Photographers".

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #50 on: January 02, 2011, 12:48:48 pm »

Representation of what,

Tristimulus values.

Quote
calculated how?

Ha ha, you asking me? I thought you were the color expert. You have full information available to work out this problem. Clock is ticking.

Quote
Standard Prophoto (D50) color space?

Yes, standard Prophoto (D50) color space, and not JoofaSpace

Sincerely,

Joofa
Logged
Joofa
http://www.djjoofa.com

#### tho_mas

• Sr. Member
• Offline
• Posts: 1799
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #51 on: January 02, 2011, 12:57:26 pm »

What is the representation of the color XYZ=[0.188185   0.075274   0.991108] in standard Prophoto (D50) color space?
the question is: where or when is the absolute chromaticity relevant?
Is there any real world application where the highest saturated blue of AdobeRGB doesn't fit into ProPhotoRGB?
Hey, you could create 2 color spaces, one in "D01" and one in "D95" so that there is no overlapping of the 2 gamuts in absolute terms. But integrated in a color mangement workflow the different white points would be mapped to each other anyway.
So, your high saturated blue of AdobeRGB is not covered by ProPhotoRGB due to the specs. But in a color management workflow ProPhotoRGB will always include all colors of AdobeRGB.
So what's the hassle about? It really doesn't help anyone...
Logged

#### digitaldog

• Sr. Member
• Offline
• Posts: 20708
• Andrew Rodney
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #52 on: January 02, 2011, 12:58:43 pm »

Quote
Ha ha, you asking me? I thought you were the color expert. You have full information available to work out this problem. Clock is ticking.

Let it tick, I have zero idea where you are going with this, we’ve been through far too many posts where you’ve been vague, insulting and dismissive. How about this, the clock is ticking on you getting clarification from Bruce about all this. Or to show us where Adobe RGB (1998) falls outside ProPhoto RGB gamut. This isn’t a problem in search of a solution, its not even a solution in search of a problem.

Quote
Yes, standard Prophoto (D50) color space, and not JoofaSpace

JoofaSpace is (was, is supposed to be) based on Adobe RGB primaries with some update you feel is necessary to alter its white point. Now you bring ProPhoto RGB into the mix and using the term “standard” when for the last time, there is no non standard ProPhoto RGB, there is only one ProPhoto RGB. And the fact you can’t show us using simple 2D or 3D graphing tools, one that is available to you on Bruce’s web site, how and where Adobe RGB exceeds ProPhoto anywhere in color space, makes me think you are simply here to waste our time.

Is there a reason you can’t or will not show us visually using either Bruce’s gamut mapping on his site, or using tools already mentioned, where Adobe RGB falls outside ProPhoto gamut? The tools are broken, the profiles are invalid, the graph on Bruce’s site is faulty?
Logged
http://www.digitaldog.net/
Author "Color Management for Photographers".

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #53 on: January 02, 2011, 01:08:43 pm »

the question is: where or when is the absolute chromaticity relevant?
Is there any real world application where the highest saturated blue of AdobeRGB doesn't fit into ProPhotoRGB?
Hey, you could create 2 color spaces, one in "D01" and one in "D95" so that there is no overlapping of the 2 gamuts in absolute terms. But integrated in a color mangement workflow the different white points would be mapped to each other anyway.
So, your high saturated blue of AdobeRGB is not covered by ProPhotoRGB due to the specs. But in a color management workflow ProPhotoRGB will always include all colors of AdobeRGB.
So what's the hassle about? It really doesn't help anyone...

Hi tho_mas, Nice to see you here. You are right there is some unnecessary arguing on. But that is the silly nature of online debates. However, we need your help. Can you please help us and identify how you drew the following graph:

verify what? These things are also available as real profiles in real applications.
This is the shape of the profiles (abscol to D50; Adobe = white)... but this is just the shape of the profiles, totally independed from any real application:

Sincerely,

Joofa
Logged
Joofa
http://www.djjoofa.com

#### tho_mas

• Sr. Member
• Offline
• Posts: 1799
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #54 on: January 02, 2011, 01:16:01 pm »

as said in the respective post: ProPhoto (wireframe) and AdobeRGB white - both unaltered - in relation to D50.
That's the grapher of Chromix Color Think ...
So in absolute terms this is the correct visual representation. But it's useless... as it shows something that will never happen.
In a (real) color managed workflow the above mentioned visual representation of Bruce Lindbloom's grapher is relevant.
That's why I don't understand what you try to achieve.
Andrew is right.
IMO.
IMHO ...
Logged

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #55 on: January 02, 2011, 01:18:14 pm »

Let it tick, I have zero idea where you are going with this,

I knew that. BTW, this is a color that is not representable in Prophoto (D50) (yes your standard space) without unity stimulus from the blue primary. If you read the link to my message that I provided above you would have known that.

Quote
we’ve been through far too many posts where you’ve been vague, insulting and dismissive.

Oh come on. I have provided graphs that I drew showing the Adobe and Prophoto primaries, written detailed and long messages on how to interpret white points, how to generate other coordinate systems in the same 3D color space. I don't think you are being fair here.

Quote

We can keep it between you and me.

Quote
Or to show us where Adobe RGB (1998) falls outside ProPhoto RGB gamut.

For the nth time see the image below and let me know if you can interpret it:

Quote
Is there a reason you can’t or will not show us visually using either Bruce’s gamut mapping on his site, or using tools already mentioned, where Adobe RGB falls outside ProPhoto gamut? The tools are broken, the profiles are invalid, the graph on Bruce’s site is faulty?

I have not seen what Bruce's gamut is showing. I tried it on my Mac but it was not loading with my firefox browser. I don't know why.

Listen: I don't think you are in a mood to learn this stuff. I can make an error and everybody including Bruce also can make a mistake. So making a mistake is not the point. The point is that you are not showing any indication to learn what I have been trying to tell you. I can only do so much effort. I don't think it is going forward. It is up to you if you want to take it forward.

Best regards,

Joofa
Logged
Joofa
http://www.djjoofa.com

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #56 on: January 02, 2011, 01:26:33 pm »

as said in the respective post: ProPhoto (wireframe) and AdobeRGB white - both unaltered - in relation to D50.
That's the grapher of Chromix Color Think ...
So in absolute terms this is the correct visual representation. But it's useless...

Hi,

I don't think it is useless. I think it shows what I am trying to say that the Adobe RGB (D65) blue region is not representable in Prophoto (D50).

Quote
as it shows something that will never happen.

Why not. I just gave an example of a color of XYZ=[0.188185   0.075274   0.991108]

Quote
In a (real) color managed workflow the above mentioned visual representation of Bruce Lindbloom's grapher is relevant.
That's why I don't understand what you try to achieve.
Andrew is right.
IMO.
IMHO ...

I think that is the basic error. Of course, I could be wrong. But I see that as an error. Repeat: After Bradford transformation the representation of [0,0,1] changes because one has changed the coordinate system.

EDIT: One can still apply the Bradford, but since the representation of [0,0,1] has changed, one has to figure out what is the right representation of that in the new coordinate system after the application of Bradford. I suspect that is what is going on here and perhaps in Bruce Lindbloom's graph (though I have yet to see them.)

Thanks,

Sincerely,

Joofa
« Last Edit: January 02, 2011, 01:41:32 pm by joofa »
Logged
Joofa
http://www.djjoofa.com

#### tho_mas

• Sr. Member
• Offline
• Posts: 1799
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #57 on: January 02, 2011, 01:41:15 pm »

I don't think it is useless. I think it shows what I am trying to say that the Adobe RGB (D65) blue region is not representable Prophoto (D50).
(...)
I just gave an example of a color of XYZ=[0.188185   0.075274   0.991108]
A real workflow example: under which conditions (which tools?) is the highest saturated blue of AdobeRGB not represented in ProPhoto?
Why don't you see any color shift when you convert a pure white from ProPhotoRGB to AdobeRGB and vice versa?
Logged

#### joofa

• Sr. Member
• Offline
• Posts: 544
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #58 on: January 02, 2011, 02:07:43 pm »

A real workflow example: under which conditions (which tools?) is the highest saturated blue of AdobeRGB not represented in ProPhoto?
Why don't you see any color shift when you convert a pure white from ProPhotoRGB to AdobeRGB and vice versa?

Tho_mas, XYZ=[0.188185   0.075274   0.991108] is the highest saturated blue of Adobe RGB (D65).

Sincerely,

Joofa
Logged
Joofa
http://www.djjoofa.com

#### tho_mas

• Sr. Member
• Offline
• Posts: 1799
##### Re: attention color whizes: non-typical sRGB/RGB/ProPhoto question
« Reply #59 on: January 02, 2011, 02:15:42 pm »

Tho_mas, XYZ=[0.188185   0.075274   0.991108] is the highest saturated blue of Adobe RGB (D65).
Lab 30|69|-114 is also the highest saturated blue of AdobeRGB.
Logged
Pages: 1 2 [3] 4 5 ... 35   Go Up