PL7 color management next steps

DxO PhotoLab
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Away from the forum for a long time I skipped the last BetaTest campaign. However I was pleasantly surprised to see that FINALLY after 12 or more years of asking, the color engine of DPL was retrofited deeply to accomodate a “ProPhotoRGB lookalike” working space. As previous “legacy” color space was close to AdobeRGB, this new working space unlocks the true potential of raw files in terms of color depths and tonality. More than anything, you do not loose colors anymore when you work in DPL. A big Kudos to that.

The softproofing tool was long overdue also, but it does most of the job but could do better.
With the automatic image analysis that DPL is capable of now, I would like DPL to provide an automated setting to propose a global compensation on contrast, vibrance/saturation, and local boosts of selected colors in the rendered copy of a picture, in case the gamut of the couple printer/paper is inducing a desaturation in an area. The basic work of softproofing is to compensate the desaturation and the changes in levels/contrasts, when you simulate the rendering of a paper. DPL could automatically create a virtual copy, analyse the settings and values of an image, match it with the destination gamut and then propose several auto settings with different priorities : priority given to keeping iso luminance, priority on saturation. It would bring a real breakthrough in color management. We have the rendering intent when we want to convert an image from a given gamut to another, we could have the “proofing intent” in response, in order to match color intent from end to end. both would be automatically done (or proposed) by DPL.

My final suggestion is when you process and export files. You get to choose the color profile of your jpg, but not the rendering intent of this conversion. In Photoshop, I always do “convert to profile” before saving a picture as jpg. During this, I can choose the engine ACE for exemple, which is the work of Thomas Knoll and is optimal), and most importantly I can choose the rendering intent of this conversion. Half doing the job is not good guys. DPL has to propose the rendering intent when we export as jpg (with sRGB most of the time).
My wife is a big fan of Rosemood photobooks. While the finishing is very nice (although rather small, I like big books when I print), I have no idea what paper they use, and I don’t know if I can share at least AdobeRGB files which is still better that sRGB. So recently my exports are done in sRGB “just in case”, and because you take no risks in the printing. As a consequence I to have to correct after the export because I cannot check the rendering intent during export.

The printing module did not change in 10 years…it needs to update as well. Preview the rendering intent, warnings in case of non supported colors dedending the rendering intent and the paper gamut. It would be nice also to print multiple image in the same sheet, with their individual settings.

Conclusion :

  • Auto settings for softproofing matching original image with the rendered virtual copy
  • Updated printing module
  • Getting to choose rendering intent during export to jpg with sRGB or AdobeRGB profiles.
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instead of exporting to a file, you can export to an app ( select color profile = DxO’s WGCS ) which is a script using for example ImageMagick that will do conversion (from WGCS to whatever you want) using your intent of choice … this is a workaround

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Ok, I didn’t know thanks. Good to know. I noticed that when I process to export 16-bit tiff files with prophotoRGB profile, when I open photoshop, it doesn’t recognize ProPhotoRGB but another unknown profile (that Photoshop happens to know and interpret well).

I have to test if DNG export could allow to retain the full gamut of my raw file but with the retouching done with DPL. I don’t think so but we’ll see.

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  1. default Soft Proofing settings
    Screen Shot 12-04-23 at 11.35 AM

  2. open the Advanced settings to check …
    Screen Shot 12-04-23 at 11.36 AM

  3. export with Same as Soft Proofing

    Screen Shot 12-04-23 at 11.36 AM 001
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rendering intent is ( not all icc profiles are compatible, but in general )

Absolute Colorimetric

Relative Colorimetric

Perceptual

Saturation

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RI … of which 2 are available … w/ printing
grafik

note
the bug in the GUI has been reported since long

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and may be he wants something else when he outputs the image to JPG file … in any case a proper software offers classic intents explicitly for that purpose and as I noted the solution ( absent effort from DxO to facilitate the matter ) is to output to a script ( instead of saving to file ) that does it ( you can have a script for each intent, again not all color profiles are suitable for all intents ) and saves to a file … DxO is using LittleCMS, so does ImageMagick, so quality of conversion will be on par between both

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With PhotoLab, Rendering Intent applies to files exported for printing.

When the export target is a digital image file (ICC Profile = sRGB, Adobe RGB, etc) then the Rendering Intent selection in Soft Proofing is ignored.

  • As noted above by Wolfgang, enabling of Rendering Intent when the ICC Profile is a digital image file is a mistake - aka a bug ! - - This was pointed out to DxO long ago, during PLv6 beta testing … but it’s another of those UI glitches that has never been fixed … Sigh !!

Instead, when the ICC Profile is a digital image file, PL applies its proprietary “Preserve Color Details” algorithm … For a LOT more info on the PCD algorithm, see here.

image

  • During beta testing, the PCD algorithm was described to us as “An algorithm developed by DxO. It’s neither the same as Perceptual or Relative Intent - it’s something in between”.

  • In my experience, the PCDA does an excellent job - and it saves us from having to make a choice between Relative and Perceptual Intent … as it’s a combination of both, tweaked for the specific requirements of each individual image :ok_hand:

1 Like
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may be yes, may be no – as you clearly can’t quantify your experience beyond subjective adjectives - but sometimes people want what is known and NOT some “marketing” stuff “in between”

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this phrase makes me wonder what do you mean here in a proper English … the matter is a conversion between 2 color spaces , a normal practice is to be able to specify a rendering intent clearly calling it that name, even if it is a home-brew contraption called “Preserve Color Details”

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I agree. DXO has done more for color management in photography than most other big name companies in the last few years.

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DXO does a great job at color management and improves on area that should have been improved on by others , long ago. “Preserve Color Details” does something the other color rendering intents have a hard time doing.

“Preserve color detail: this slider applies only to matrix based ICC profiles, so only display profiles – not printer profiles. Set at 50 by default, the slider lets you alter saturation and details in saturated portions. By reducing the value (to the left), the slider maintains saturation to the detriment of the details and, To the right, the details are preserved to the detriment of the vivacity of the colors. Note that the Export menu has a Preserve color detail checkbox which gives you the option to apply the slider’s effect to the exported images.”

That is a lot more control than standardized and outdated rendering intents that were limited when they were implemented for the first time and were never updated.

DXO PhotoLab is first and foremost a RAW processing application. Meaning it takes the raw data from an image file and provides tools to develop it to your liking and tries to preserve that on export. Color rendering intent has been replaced by a better system, which does this job better.

If you are working with non raw files than having standardized rending intents as an option might be reasonable, but not for raw files. However, rendering intent is only there to provide a compromise between working profile and output profile and nothing more. Therefore the is no real advantage to use; Absolute Colorimetric, Relative Colorimetric, Perceptual, Saturation other than dealing with this compromise. And DXO offers its own solution that is better.

If you really want for some strange reason to keep standardized rendering intents in DXO it might be convenient to have them in DXO, but it should not be a big deal for anyone who is into this kind of stuff. You can export a file with largest color space, like ProPhoto RGB and use any other app that supports these rendering intents to do the conversion. I don’t see any inherent advantage to that , but it is possible.

That being said you do have two options for rendering intent: Relative Colorimetric and Perceptual in the soft proof panel. As Wolfgang has pointed out.

You can carry over this when exporting an image, including the preserve details, DXO proprietary mode.

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I don’t see where the problem is. It works and it works well.

I think that is already implemented.

I don’t know if people want to print from DXO or just soft proof, since there seems to be better more dedicated solutions for printing including specialized software from the printers and off course many do in fact send their files to be printed by printing labs. But I guess it could always be improved.

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such as what ?! marketing claims excluded ? did they design an industrial grade CMM/CMS ? or licensed LittleCMS from a one man outfit like Marti Maria ?

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Are you being a contrarian on purpose, as per usual, because you must know what they have done. By the way, its time you find a name for yourself. Its impolite to pretend you don’t have one.

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you simply parroting a lot of adjectives from marketing materials

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You are simply trolling Mr. straw man. go fetch a better argument, and find a name, than come back.

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reminding what DxO said on record upon v7 release : “create your own calibrated color profiles from within PhotoLab for scientifically accurate colors.”

yes, that was a great contribution to the color management… a simple matrix profile DCP profile of a target with a just one “cyan” patch barely outside of sRGB gamut… scientifically accurate colors my proverbial body part :slight_smile:

next claim was there nearby = “For the first time within a RAW image editor, DxO PhotoLab 7 lets photographers calibrate images directly within the interface.”… this is NOT true, others did way earlier and better ( Phocus raw converter from Hasselblad for example )

Did they remove all that ?

Great unrecognized contributors … ICC stands ashamed

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Oh just save some time and do everything with DPL instead of needing to open Photoshop to know what you are doing and have a consistend colorfeedback when you softproof. if PCD is a homebrew version of ACE from Photoshop ok, but you could/should choose because depending of the image you have, different rendering intent could be of use to optimize the output gamut (be it a paper, a screen, or your book printing service online).
Yes when I print, I export with ProPhotoRGB which is, by the way, no fully detected all the time by Photoshop (instead another profile close, but it’s ok), and need to go to Photoshop to softproof, simulate and then print from it.

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Where? Maybe I am not clear : I mean auto softproof. Auto compensation on various metrics of the image, for the simulation of a rendered proof copy to match the original copy of an image (or get as close as possible to the human eye). That is not done IMO.