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HSB Color Mode

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Lee Harper:
(because of its general interest, I've added Lee Harper's post to Articles.  We welcome your additions and comments - Mike and Greg)

Hi everyone,

I'm almost at the end of the CM 101 course, and one of the things that I keep wondering about is when HSB should be my 'go to' color mode?

I really like the saturation curve, and it's usually quite obvious to me when the saturation curve would be a good choice, but I'm struggling a bit with the Hue and Brightness curves.

I've two questions. I'm not looking for definitive answers - I'm just interested to hear how everyone else approaches this:

* Why use the Brightness curve instead of the L curve in Lab? Does it have any special properties?
* Why use the Hue curve at all? For the life of me I've no idea how to even begin to approach Hue in HSB.
Greg has been kind enough to give me his opinion about HSB, and it would be great to know how others approach these two questions.

All the best,
Lee.

sjordan93436:
(I know this is an old topic.)

HSB...  the brightness seems to be very similar to the L of LAB. 

The Saturation is interesting.  It allows you to bump or drop saturation in a range.  I wonder how good that will be.  Decreasing skin saturation might decrease some leaves with the same saturation.  ....  Seems like it needs a mask or selection.

Hue.. Potentially interesting.  You can target a certain hue to move.  Same problem as with saturation.  Other problem is the 0 line.  Red is zero.  Going from 5 to 15 easy.  Going from 5 to 355 with a curve, not so easy.

It seems to me to be specialized with good selections of masking to fix hue/ saturation problems.  Or for changing a broad range of saturation.

I have many photos with skin that is 355.  More magenta than yellow.  Unfortunately that little bump to positive 5 or 10 is not easy.  Unfortunately the hue shift affects lips and hair. 

HSB??  Not mainstream yet.

Lee Harper:
Hi Steve,
Thanks so much for your thoughts :)

I'm still in a place where HSB seems interesting, but is yet to prove useful. I'm hopeful that a new Color Correction book can help me turn the corner though. It's called 'The Color Correction Handbook: Professional Techniques for Video and Cinema' by Alexis Van Hurkman (www.peachpit.com/store/product.aspx?isbn=0321713117), and it contains an entire chapter about using HSB for color correction.

From the table of contents:
* HSL Qualification in Theory
* Individual Qualifier Controls
* A Basic HSL Qualification Workflow
* Tips for Using and Optimizing HSL Qualifications
* Different Ways of Using HSL Qualifiers
* Hue Curve Adjustments
* Other Types of HSL AdjustmentsI have ordered a copy into the library where I work; I'll report back to everyone anything that I pick up from it...

All the best,
Lee.

sjordan93436:
BTW- this is so obscure, I do not consider this a bug.  ....  Pinning colors in HSB is (ahem) inconsistent at best.  Why anyone would want to pin is beyond me.  I was messing around.  I guess if you selected a sky (for example) that might make sense.   I might have been the only guy to try this.  It has no utility as far as I can see.

I think from a programming perspective, Mike needs to get the information for the hue clocks.  That information is essentially HSB.

curvemeister:
 Pinning to a particular HSB value may not be very valuable, but a hue, saturation, or brightness pin might be useful.  Could you describe the behavior?  Maybe it is a bug.

If you like obscurities, HSB is definitely closely related to the hue clock.  The hand position is the hue, and the length of the hand is the saturation.  There is an option, under settings, to use an Lab based hue clock, where the clock hand position and length are based on the a and b values of the color.  There is also another option to offset the hue clock, for people who are used to red being at a different position on the clock.

Even more obscure, when a sample is averaged in HSB space, I actually average the values of the hue clock angle, rather than the hue values themselves.  This avoids the problem of the discontinuity at zero, which is really HSB's big Achilles heel.

HSB was invented by Alvy Ray Smith (Alvy mentions HSB is several articles on his web page), and the best article I know of on the HSB family of color spaces was written by Jacob Russ.

Mike

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