It would be useful indeed to have the proper labels, but one does not need to be a genius to know wich is wich… (besides the fact that you have to remember if you choosed B or L) I think that we don’t have a real support but a workaround.
This is basically a useless feature.
The hue channel splits the reds in half with the warm reds at one side of the grayscale and the cool reds at the other, with a sharp black/white dividing line where the red hue angle flips from 359° to 0°.
Makes for a bizarre display.
Yes the 3 channels are generated in accordance with the HSB values you can see in the info palette, but they remain labeled as RGB, and display that way. I can’t see effectively editing in that mode.
OK it may not be totally useless.
You can dip into it to get a saturation grayscale that you can then use as a mask in RGB.
Though you have to get used to the fact that 0R/0G/0B is 0% saturation while 1R/0G/0B is 100% saturation…
It’s a color science thing I guess.
Hi John,
Thanks for the info. So the channels are just mis-labeled.
Why are the colors in the image display so radically transformed when going from RGB to HSL (or HSB)?
I understand the H and S channels are going to indivudually look weird, like the a and b channels in Lab color space, but why does the composite color display look so freaky?
Jerry
see my last post 2nd paragraph
Hi John,
I understand what you are saying, but I still don’t understand why the composite color channel looks weird.
The composite channel in Lab color doesn’t look weird like this…
Thanks,
Jerry
Because the channels are displaying just as they would if they were RGB channels.
No, that’s not right either.
THEY ARE RGB channels, constructed from the HSB content of the file when you invoked the plugin.
Don’t make the mistake of thinking you have converted to an HSB color mode. You haven’t. It is still an RGB file. The channels are not mislabelled, they are what they are.
This is why I say the feature is almost useless.
Hi John,
I’m trying to use this Photoshop RGB > HSL filter for a technique for astronomical photography where a high resolution black and white image is combined with a low resolution color image. This saves exposure time on the color, and since exposures can run for hours, it helps.
Usually the b&w is substituted for the L channel in Lab color, or blended as a luminance layer into the RGB document. But when this is done, the colors get muted.
I wanted to try the substitution in HSL color.
Thanks,
Jerry
What happens when you set the low rez color image on top of the B&W, setting the blending mode to color?
Exactly the same thing as pasting the hires luminance on top of the color and setting the blending mode to luminance.
Jerry,
HLS,HSB are coordinate systems which produce RGB numbers. Man-machine interfaces for a better "navigation" in the RGB cube.
It´s never recommended to use HLS,HSB for image processing. Especially in HSB the "Brightness" is really odd: B=Max(R,G,B). Both color order systems are nonlinear, discontinuous and colorimetrically wrong. Better use Lab.
Of course they are not useles. E.g. the choice and modification of colors for websites is much simpler in HLS than in RGB. HLS is sometimes called HSL, should be the same. HSB is dif- ferent.
In my understanding the B/W image can be colorized like this: Convert B/W to Lab.
Result L1 and a1=0,b1=0.
Eventually desaturate Color image.
Result L2,a2,b2.
Combine L1,a2,b2.
Best regards –Gernot Hoffmann
Hi Gernot,
Thanks for the info, it doesn’t look like I will have much use for HSL and HSB.
Jerry
