Author Topic: Working in LAB colorspace would be nice  (Read 291 times)

MikeMoyle

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Working in LAB colorspace would be nice
on: January 23, 2022, 12:10:13 AM
Hi, I had originally posted in the Help forum but no one seemed to have any suggestions on how to do this, so I thought that maybe it's a request for a later release. If this sort of crossposting is inappropriate the,Mods, please delete this thread.

What I would like to be able to do is to work in LAB color pace and, more specifically, in individual channels in that space. LAB has three channels: L = Lightness - essentially the black/white values, A = Red/Green Values, and B = Blue/Yellow Values. The catch is that the L channel is where we see the bulk of the fine detail in an image. Being able to separate that from the underlying color distributions means you can fiddle with your colors and leave the light/dark values intact, or vice versa.

As an example, I have some printed artwork that was scanned in such a way that the halftone dots of the 4-color printed page and the scan resolution create a moire effect. Back when I was working in PShop, I could set the colorspace to LAB and put a slight blur filter onto JUST the A or B (color) channels, without blurring the L (lightness) channel. This would fuzz the colors to smooth out the moire effect, but leave light/dark values (the fine detail) unchanged. It's an incredibly useful hack - in fact, working in LAB space is useful for a LOT of purposes and it would be great to, somehow, be able to work in it. (Hint : It's also MUCH better for color-shifting an object - Like if you have a picture of a blue sportscar and the client decides that they want it to match the red in the corporate logo!)

Seriously, if this isn't available in ASP right now, it really should be.

Thanks!

Pikachu

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Re: Working in LAB colorspace would be nice
Reply #1 on: January 23, 2022, 06:54:51 PM
it's there for me...

Lucky Clan

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Re: Working in LAB colorspace would be nice
Reply #2 on: January 25, 2022, 03:38:28 AM
Yes, i agree Lab is often very helpful to do some tuning.

Implementing Lab color model is a bit too complex and time consuming.
But adding option to add 3 layer (L,a,b) from current layer, and another option to merge them can be considered.

Or maybe this way Edit > Copy/Paste Channel > r|g|b|L|a|b...

Or just adding Channel selection (L,a,b,r,g,b) to some selected (or all) filters
Last Edit: January 25, 2022, 03:46:43 AM by Lucky Clan

Pikachu

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Re: Working in LAB colorspace would be nice
Reply #3 on: January 26, 2022, 03:32:29 AM
oh woops i misunderstood, yeah +1 to this, it would be really helpful with values