Re: Softimage and CMYK

[Jason S]

I found out when wanting to copy the lightness channel from the CMYK image converted to lab to paste it in an RGB ver, and saw that just converting all of it from there to RGB seemed to do the trick. Maybe because as lab works with a lightness channel, it doesnt need to do any specific curve manipulations to recreate levels in another space    but go figure. nevertheless, hope that can work! J On 02/12/16 10:13, Jason S wrote: You can have CMYK images in 16 or 32 too, but if your sources are 8 bit, it can be fine if there aren't too wide gradients or making wild corrects. But here's what seems to work, converting from CMYK -> Lab Color  seems to keep all levels as they were, and then from Lab Color -> to RGB  ... also seems to keep all levels as they were! (It might be best to convert to 16bit (if they were in 8) before doing so.) Cheers, J On 02/12/16 10:08, Sebastien Sterling wrote: I think it has to do with RGB being additive; adding all colors leads to white and CMYK being subtractive. adding all colors leads to black RGB has so many more colors, it must be like clamping the bit depth but not quite. at any rate you loose something going one way, so it is a destructive workflow. On 12 February 2016 at 14:55, Jason S <jasonsta...@gmail.com> wrote: It weird because if you take screenshot while in CMYK colorspace and paste in an RGB image, there you go, same blacklevels and everything as in CMYK but in RGB space. So would there be a way to "bake" color info from one colorspace to another? (assuming it's for hirez images, otherwise you could just take screenshots :P ) I find it surprising that something like photoshop cant manage to make a 1:1 conversion. On 02/11/16 18:19, Sebastien Sterling wrote: Have been doing variants of this, to no great success, it doesn't seem to want to change anything, haven't tried absolute colometric though, maybe i will try that. The Web converter actually does have an effect, but not perfect, it does bring the ultramarines back towards black. On 11 February 2016 at 23:02, Sven Constable <sixsi_l...@imagefront.de> wrote: Photoshop Edit->Convert To Profile You will see the source color space embedded in the original (if there is any) and the target color space. Choose  one of the RGB spaces (eg. sRGB). Check blackpoint compensation and Relative Colometric. Tick Preview to see the result. Ideally you should see no to minimal color shifting, but this depends on the original color profile within the CMYK file.   I'm pretty sure this what you'll get with that web based converter. However, your problem is not to get a close color match but to change colors (ultramarine blue to black). Not sure if this is possible without manual grading but you can try unchecking black point compensation and switch to Absolute Colometric. Then switch through the different color profiles and see if any of it will change the ultramarine blue back to black. If this worked somehow, do a second conversion to sRGB with blackpoint compensation ON and relative colometric.   If this won't work, I think there is only manual color grading or have the client send you "correct" files.   sven