I am advocating for years for a decent printing module for end-to end color management system within DxO, but I also know this a lot of work.
Soft proofing being the most obvious feature.
For high resolution fine art printing and signature work, there is an un-clarified topic about the internal working colorspace of DxO. Years ago (before PhotoLab, back in the DxO days) I was told by an engineer that it was close to AdobeRGB but couldn’t give proper documentation about it because it was a sensitive matter. This colorspace was used by the root algorithms for handling demoisaicing/denoizing/ raw processing at the same time (the strenght of DxO), and was nearly impossible to change without heavy investment and research.
Ever since we have seen updates in the raw processing (with spectacular results), but nothing on the color management topic.
I think the DxO guys’ rationale is that if you want to have serious printing workflow, you’ll either invest in a RIP, or use Photoshop. Luminous-landscape made several videos on how to use Softproofing when going from camera to print. This process is/was still “state of the art” for printing serious work, without using costly RIP softwares.
That would make sense if and only if this colorspace issue was clearly documented and clarified. If working with DPL make it hidden and mandatory to go through a hardcoded AdobeRGB-lookalike color space, you simply clip your colors and tonalities since the GAMUT of your camera, and most importantly, the GAMUT of your printer (given you use serious printers with large gamut, like ultrachrome HDR inks from Epson) is larger than AdobeRGB. In photoshop and Camera RAW your can process your raw with the color workspace set to ProphotoRGB, which is the proper workspace if you want to cover all the gamuts and not clip anything (though using it require a fair dose of care. Serious use only).
When you go from a colorspace to another you’ll have to use a rendering intent, ie choose the methods for handling the colors that are outside the destination colorspace…do you clip? do you shrink? All these settings are hidden and we simply don’t know how DxO process it.
I also think the foundation work of Thomas Knoll, the Father of Photoshop laid tons of patents that are difficult to avoid when you want to address the issue. Thomas has made amazing work to colorspace conversion, it took him years.
Long story short => two topics :
If your finality is everything but printing…DPL is very good (viewing pictures on screens, on the web…requires sRGB only, and seldom require adobeRGB which is large).
If you want to print…unless DxO clarifies which colorspace they are using, and make it so the user can choose ProPhoto from the very start…well you’ll loose colors and data from your camera, that your printer could have made use of. And THEN softproofing would make sense (and would be mandatory).