Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: supercurio on September 13, 2014, 03:14:39 pm

Title: DNG color profile Color Tables generation from any target
Post by: supercurio on September 13, 2014, 03:14:39 pm
I'm about to start writing code for a brand new tool to generate DNG/DCP HueSatMap.

Neither X-Rite nor Adobe tool provide satisfying and consistent results in my experience, and both are also limited as their input is only 18 hard-coded colors.

Specific issues encountered with

Adobe DNG Profile Editor:
X-Rite ColorChecker Passport software:

The software I'll write will accept XYZ for various illuminants or maybe spectral data directly as input for the patches, and charts of any dimensions.
Typically, first ones I'll use are the X-Rite Digital SG (140 patches, 14x10) and for comparison the CMP Digital Target 4 (570 patches, 30x19)

Do you know if any existing program already does that?
This is a tool I'll use as differentiator in my next product, the goal is get the calibration as good and consistent as it gets :)
Title: Re: DNG color profile Color Tables generation from any target
Post by: supercurio on September 18, 2014, 09:24:52 pm
Okay I started writing the software described :)

After some initial experimentats, I'm a bit puzzled by the usage of HSV as color space for the profiles.
Typically, reducing saturation in HSV makes some colors a lot brighter as it is not perceptual.
I made those experiments on gamma-encoded RGB values tho so probably this won't be as much of an issue in DNG color profiles: they're applied on linear RGB data.

In practice, one example you'll encounter often because of that when you use Adobe DNG Profile Editor is blue or sky colors ending up too light.
I believe it doesn't have to if using more of what's the DNG spec, but this free tool does not and end up too limited.

Let me know if you have remarks or questions on this DNG calibration project. I can't wait to make my own profiles with it!
Title: Re: DNG color profile Color Tables generation from any target
Post by: ricgal on October 08, 2015, 10:03:27 am
Hi
I realise you started this post was started a while ago
I wondered if there is any software about for making DNG profiles for CMP or colorchecker SG targets?
thank you for your help
Title: Re: DNG color profile Color Tables generation from any target
Post by: Alexey.Danilchenko on October 08, 2015, 10:10:03 am
Quote from: ricgal on October 08, 2015, 10:03:27 am
I wondered if there is any software about for making DNG profiles for CMP or colorchecker SG targets?

What's wrong with dcamprof (http://forum.luminous-landscape.com/index.php?topic=100015.0) which lives just here in a neighbouring thread and does exactly that?
Title: Re: DNG color profile Color Tables generation from any target
Post by: supercurio on October 08, 2015, 10:13:25 am
Hi ricgal!

I worked on other projects since and didn't make progress on that one yet.
It's perfectly possible to make profiles from any target indeed, sorry I didn't look into existing software however.

- And while I'm writing this, Alexey just gave a better answer :)
Title: Re: DNG color profile Color Tables generation from any target
Post by: xpatUSA on October 15, 2015, 09:42:44 pm
Quote from: ricgal on October 08, 2015, 10:03:27 am
I wondered if there is any software about for making DNG profiles for CMP or colorchecker SG targets?

Have you looked at this?

http://muscallidus.com/coca/

Ted
Title: Re: DNG color profile Color Tables generation from any target
Post by: AlterEgo on October 16, 2015, 12:08:16 am
Quote from: xpatUSA on October 15, 2015, 09:42:44 pm
Have you looked at this?

http://muscallidus.com/coca/

Ted

and did you ?  it is for ICC/ICM containers... not DCP (aka DNG profiles).