Timeline for How to display hue or saturation information as a greyscale bitmap?
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
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| Sep 12, 2018 at 6:45 | comment | added | meh | Thanks for mentioning LAB, I'll give it a look and see if it is suitable for non destructive adjustments. | |
| Sep 11, 2018 at 22:40 | history | edited | user82991 | CC BY-SA 4.0 |
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| Sep 11, 2018 at 22:35 | comment | added | user82991 | @joojaa the thing "detecting and classifying skin color variations" should be worked in CIELab (=Lab in Photoshop), but the questioner didn't ask it. | |
| Sep 11, 2018 at 22:32 | comment | added | user82991 | @meh I must admit that this case has revealed a hole in my knowledge. I had different calculation for the saturation than the generally used. The lightness (=the average of brightest and dimmest RGB channel has been replaced with a BW mix of the RGB channels. The resulted quantity isn't the usual RGB saturation altough it presents the same visible thing. These are the usual formulas rapidtables.com/convert/color/rgb-to-hsl.html. I must remove the claim the saturation can be presented as BW with blending modes and adjustments in Photoshop. | |
| Sep 11, 2018 at 18:25 | comment | added | joojaa | Might also be worth working in lab mode. | |
| Sep 11, 2018 at 13:38 | comment | added | meh | Yes, it's always nice to know and experiment with new workflow tools, may give me good ideas even if I end up not using it right away! | |
| Sep 11, 2018 at 7:25 | vote | accept | meh | ||
| Sep 11, 2018 at 7:25 | comment | added | meh | First of all thank you for a solution to my problem and a clear explanation of the hue caveat. Obvious once you think about it. One would have to write a filter that, say, will shift the discontinuity to a hue that is of no matter, for example green when looking for skin imperfections. The example image is just that: something random used to show what I meant, it is by no means a picture that represents what I would call a good shot. :) Could you add to your answer the way to display saturation with layer blending modes? | |
| Sep 10, 2018 at 10:52 | history | edited | user82991 | CC BY-SA 4.0 |
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| Sep 10, 2018 at 10:14 | history | edited | user82991 | CC BY-SA 4.0 |
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| Sep 10, 2018 at 9:25 | history | edited | user82991 | CC BY-SA 4.0 |
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| Sep 10, 2018 at 8:46 | history | edited | user82991 | CC BY-SA 4.0 |
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| Sep 10, 2018 at 2:35 | history | answered | user82991 | CC BY-SA 4.0 |