Blackmagic Forum

I would love to see a proper naming scheme for all the color spaces.
Preferably all the commonly used combined ones with a '/' to divide like most of them are.
For me the 'dummy proof' naming schemes create more confusion than clarity.

Project Settings Color Space List:
ACES -> AP0/Linear or ACES2065-1
ACEScc -> AP1/ACEScc
ACEScct -> AP1/ACEScct
ARRI LogC -> ARRI Wide Gamut/LogC or AWG/LogC

CST Color Space:
ACES -> ACES (AP0)
ARRI Alexa -> ARRI Wide Gamut

ACES Transform:
Alexa -> ARRI Wide Gamut/LogC or AWG/LogC
Add missing color space -> ACES2065-1

Remove all CSC labels on those color spaces and remove any duplicates.
RWG/Log3G10 is the same as RED Log3G10 REDWideGamutRGB - CSC
Initially the idea in the node was to only have Display targets as output spaces but in practice this is not the only task an ACES transform should do so CSC versions were added to both input and output lists but we really just need the actual to be the same on both sides. Make the input list equal to the output list!
This should also fix the sorting in alphabetical order so non display transforms (with - CSC at the end) are easily reachable like ACEScct which is probably used more often than the huge display list.

Alternatively you could split out these to ACES Display Transform and ACES Color Space Transform by having a setting inside the node to tell whether you want to go to display or not and thus changing the list accordingly to clean it up.

Curious how others feel about this.

+1

Current namings are ambiguous and don’t properly define colorspaces.

+1 for cleanup

+1

+1

+1

Hello
I'm french and I teach Resolve
I use the word "ColorSpace/Espace Colorimétrique" only for referring a 3 dimensions "space" ...like ACES2065-1
I use the word "Gamut" only for referring a 2 dimensions ... like AP1 or AP0
I use the word "Gamma" only for referring a 1 dimensions ... like Linear
It's very simple for the the trainees to understand colorspace that way

But the OFX ColorSpaceTransform and other places in Resolve use the word ColorSpace" either for 3 & 2 dimensions .... witch is very confusing don't you think so ?

Olivier MATHIEU wrote:Hello
I'm french and I teach Resolve
I use the word "ColorSpace/Espace Colorimétrique" only for referring a 3 dimensions "space" ...like ACES2065-1
I use the word "Gamut" only for referring a 2 dimensions ... like AP1 or AP0
I use the word "Gamma" only for referring a 1 dimensions ... like Linear
It's very simple for the the trainees to understand colorspace that way

But the OFX ColorSpaceTransform and other places in Resolve use the word ColorSpace" either for 3 & 2 dimensions .... witch is very confusing don't you think so ?

... AP1 and AP0 still refer to a three primaries color space....

are you doing the distinction:
1) ACES2065-1 - that define both the volumetric primaries AND tonal range
2) AP1 - that only define primaries
3) "linear light" - that only define tonal range?

waltervolpatto wrote:... AP1 and AP0 still refer to a three primaries color space....

For me AP1 & AP0 are "Gamuts". A gamut is defined by 3 primaries and a White point
Those 4 points are defined by only 2 coordinates each ➧ it is not 3 dimension

waltervolpatto wrote:are you doing the distinction:
1) ACES2065-1 - that define both the volumetric primaries AND tonal range
2) AP1 - that only define primaries
3) "linear light" - that only define tonal range?

Yes, exactly
For me
1) is a Color Space
2) is a Gamut
3) is a Gamma or "gradation" (in french" ) ... it's more like tonal range as you mentioned

e.g : The new resolve "ColorSpace" in Resolve 17 is made of
1) a Gamut called "Davinci wide Gamut"
2) a Tonal range called "Davinci intermediate"

Neither of "Davinci Wide Gamut" OR "Davinci Intermediate" IS a ColorSpace (3 dimensions)

it seems to me clearer. no ?

I think OFX ColorSpaceTransform confusing ... and may be to all people who want to learn more ....
EDIT

Look : about the mapping it's "Gamut mapping" (Correct for me) and not "ColorSpace Mapping"

Olivier MATHIEU wrote:For me AP1 & AP0 are "Gamuts". A gamut is defined by 3 primaries and a White point
Those 4 points are defined by only 2 coordinates each ➧ it is not 3 dimension

Gamut is three-dimensional as Walter wrote. The fact that it is defined by tuples in xy space doesn't change that, because they are actually xyY values with Y == 1.0, so three dimensions with one conveyed implicitly.

Otherwise I agree, what needs clear separation in Resolve is gamut and transfer function (tonal range). Transfer function is more widely used term than tonal range I believe, because "range" means definition of endpoints, but we are also interested in what happens inbetween, the function of how input values are mapped to output values. Gamut and transfer function together form a colorspace. Neither of them separately does because one or another must be deduced somehow and it produces most of the current ambiguity.

Hendrik Proosa wrote:Gamut is three-dimensional as Walter wrote. The fact that it is defined by tuples in xy space doesn't change that, because they are actually xyY values with Y == 1.0, so three dimensions with one conveyed implicitly.

I'm confused : in xyY is Y the the "tonal range" ?
Is xyY a ColorSpace ?
Where Can I read more about that ?

Hendrik Proosa wrote:Otherwise I agree, what needs clear separation in Resolve is gamut and transfer function (tonal range). Transfer function is more widely used term than tonal range I believe, because "range" means definition of endpoints, but we are also interested in what happens inbetween, the function of how input values are mapped to output values. Gamut and transfer function together form a colorspace. Neither of them separately does because one or another must be deduced somehow and it produces most of the current ambiguity.

Agreed

Olivier MATHIEU wrote:I'm confused : in xyY is Y the the "tonal range" ?
Is xyY a ColorSpace ?
Where Can I read more about that ?

xyY is a derivate of XYZ colorspace, xy gamut plot is in essence a projection of xyY space which removes the third axis. Big Y component is the Y from XYZ and directly expresses luminance. Since x and y coordinates don’t depend on the absolute values of XYZ (XYZ values can be scaled with a scalar and derived xy won’t change), this projection is normalized by luminance. This stability of xy coords in relation to absolute power is also the reason why one can’t go out of gamut by simply changing the magnitude of values in linear RGB based colorspaces. Only way to go out of gamut (in its color science meaning) is to set one or more primaries negative.

It is covered a bit in wikipedia: https://en.wikipedia.org/wiki/CIE_1931_color_space

+1

Thanks

Hendrik Proosa wrote:xyY is a derivate of XYZ colorspace, xy gamut plot is in essence a projection of xyY space which removes the third axis.

So the gamut is 2D
I think we are agree but we express it with different way

Hendrik Proosa wrote:Big Y component is the Y from XYZ and directly expresses luminance. Since x and y coordinates don’t depend on the absolute values of XYZ (XYZ values can be scaled with a scalar and derived xy won’t change), this projection is normalized by luminance.

I learn something

Hendrik Proosa wrote:This stability of xy coords in relation to absolute power is also the reason why one can’t go out of gamut by simply changing the magnitude of values in linear RGB based colorspaces. Only way to go out of gamut (in its color science meaning) is to set one or more primaries negative.

It is covered a bit in wikipedia: https://en.wikipedia.org/wiki/CIE_1931_color_space

In this webpage it says "CIE xy chromaticity diagram". Xy is 2D and Gamuts are shown on chromaticity diagram....

Please enlighten me if I'm wrong ..

+1
Technically accurate naming is always preferable in professional environments.

Olivier MATHIEU wrote:In this webpage it says "CIE xy chromaticity diagram". Xy is 2D and Gamuts are shown on chromaticity diagram....

xy diagram is a 2d view of 3d space, thus it is a projection. To tell how long and wide a car is you need just the top view of it, but it doesn’t mean that car is flat