I was going to say, make sure you assign the same ICC profile to the image in Photoshop that you use to make the conversion in Lcms. Otherwise, you are comparing apples with oranges.
/ Roger -----Original Message----- From: lcms-user-requ...@lists.sourceforge.net [mailto:lcms-user-requ...@lists.sourceforge.net] Sent: Thursday, September 1, 2016 8:06 AM To: lcms-user@lists.sourceforge.net Subject: Lcms-user Digest, Vol 112, Issue 1 Send Lcms-user mailing list submissions to lcms-user@lists.sourceforge.net To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/lcms-user or, via email, send a message with subject or body 'help' to lcms-user-requ...@lists.sourceforge.net You can reach the person managing the list at lcms-user-ow...@lists.sourceforge.net When replying, please edit your Subject line so it is more specific than "Re: Contents of Lcms-user digest..." Today's Topics: 1. Conversion issues (Christopher Polewczuk) 2. Re: Conversion issues (Christopher Polewczuk) 3. Re: Conversion issues (Marti Maria) ---------------------------------------------------------------------- Message: 1 Date: Wed, 31 Aug 2016 13:30:50 +0000 From: Christopher Polewczuk <cpolewc...@globalvisioninc.com> Subject: [Lcms-user] Conversion issues To: "lcms-user@lists.sourceforge.net" <lcms-user@lists.sourceforge.net> Message-ID: <yqbpr01mb02098da7d442eb73cffed886db...@yqbpr01mb0209.canprd01.prod.OUTLOOK. COM> Content-Type: text/plain; charset="us-ascii" I have a rgb tiff with an embedded profile from a calibrated scanner. I am using that profile and an output sRGB profile, but the results do not match photoshop's results, when opening the same file and converting with the inbuilt profile. The results do match gimp though, but our color calibration tool matches photoshop. -------------- next part -------------- An HTML attachment was scrubbed... ------------------------------ Message: 2 Date: Wed, 31 Aug 2016 17:16:25 +0000 From: Christopher Polewczuk <cpolewc...@globalvisioninc.com> Subject: Re: [Lcms-user] Conversion issues To: "lcms-user@lists.sourceforge.net" <lcms-user@lists.sourceforge.net> Message-ID: <yqbpr01mb02099b6a7eb426a9e9ab4a46db...@yqbpr01mb0209.canprd01.prod.OUTLOOK. COM> Content-Type: text/plain; charset="us-ascii" For my input profile, Color Space : Rgb Pcs: Lab I do a transform from the embedded profile to lab using cmsCreateLab4Profile,Then I convert from lab to rgb using cmsCreateLab4Profile & cmsCreate_sRGBProfile. No flags and using perceptual from the icc The resulting image is darker than the one generated in photoshop or gimp. -------------- next part -------------- An HTML attachment was scrubbed... ------------------------------ Message: 3 Date: Wed, 31 Aug 2016 20:28:07 +0200 From: Marti Maria <marti.ma...@littlecms.com> Subject: Re: [Lcms-user] Conversion issues To: Christopher <cpolewc...@globalvisioninc.com>, lcms-user <lcms-user@lists.sourceforge.net> Message-ID: <fkd82sobsgs8b7rroeghonmg.1472668087...@email.android.com> Content-Type: text/plain; charset="utf-8" Hi, In general, lcms matches quite well photoshop. But to get same results you have to use same profiles and same settings. For example, if PS is using the file based sRGB v2, you should use this file instead of the built-in sRGB, which is v4. In perceptual and converting to lab there is a difference between v2 and v4. You could also use a direct transform, from the embedded profile to v2 sRGB. Tifficc may be handy here. If the direct transform fails, send me the embedded profile and a the numbers of a couple of rgb values (please, don't send the whole tiff!) And i will take a look. Regards Marti On Aug 31, 2016 7:16 PM, Christopher Polewczuk <cpolewc...@globalvisioninc.com> wrote: -------------- next part -------------- An HTML attachment was scrubbed... ------------------------------ ---------------------------------------------------------------------------- -- ------------------------------ _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user End of Lcms-user Digest, Vol 112, Issue 1 ***************************************** ------------------------------------------------------------------------------ _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
