Timeline for What Conversion Engine works best in Photoshop? ACE or ICM
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
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| Apr 7, 2021 at 19:22 | comment | added | doug | @Tetsujin Thanks. I incorporated the results. Turned out the 8 bit stuff was useful in demonstrating the effects of using 8 bit images when converting. Not as bad as I expected. | |
| Apr 7, 2021 at 19:20 | history | edited | doug | CC BY-SA 4.0 |
new data on 16 bit colorspace conversions with both Apple and Windows OS
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| Apr 7, 2021 at 9:40 | comment | added | Tetsujin | Darnit - I never even thought of that, sorry. I'd assumed the ones from the site were 'correct':\ I redid them after 16-bit conversion. dropbox.com/sh/316ctx3a6xlrl77/AABQ6F2itP5CMaUH5bGj-LoOa?dl=0 Link looks the same, contents are now 16-bit. | |
| Apr 7, 2021 at 5:03 | history | edited | doug | CC BY-SA 4.0 |
added 615 characters in body
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| Apr 6, 2021 at 20:31 | comment | added | doug | @Tetsujin I'm assuming you didn't first convert to 16 bit tiffs. My measurements were made with 16 bit tiffs. | |
| Apr 6, 2021 at 20:28 | comment | added | doug | @Tetsujin Both Apple and Adobe's CMM produced similar results. The maximum deltaE error was 2.5 for both and looks like just the effect of using 8 bit RGB which results in rounding errors. The maximum deltaE error occurred for Apple CMM RGB(10,31,40) > RGB(13,29,40) while Adobe ACE's max was RGB(18,26,28) > RGB(20,24,28). I get different results with 8 bit images on Windows Adobe ACE so it looks like the math differs a bit. Wouldn't surprise me as there is a lot of handwritten, low level code and the hardware historically differed too. | |
| Apr 6, 2021 at 8:51 | comment | added | Tetsujin | Conversions done as per your method, using image source from Bruce Lindbloom. Shared on DropBox - dropbox.com/sh/316ctx3a6xlrl77/AABQ6F2itP5CMaUH5bGj-LoOa?dl=0 - Hope I got it right ;) I can't tell the difference visually, but I guess that would be expected. | |
| Apr 5, 2021 at 20:37 | comment | added | doug | @Tetsujin I just used Matlab to create a 4096x4096 tiff image with all possible RGB values. Then did the conversions in Photoshop and compared the result for the largest error. Very easy in Matlab and probably in Python as well. BruceLindbloom's site has an image with all possible RGB values as well. If you try that one and post a link to the converted image I'll take a look. | |
| Apr 5, 2021 at 6:36 | comment | added | Tetsujin | It might be interesting to get Apple CMM measurements to go alongside these. I you could post your original somewhere, I could do the test conversions if you could measure the results [I've no clue how to do that;) tbh, I've always just used Adobe ACE because it's the default. | |
| Apr 4, 2021 at 22:20 | history | answered | doug | CC BY-SA 4.0 |