Talk:HSL color space

From Wikipedia, the free encyclopedia
This article is supported by the Color WikiProject.

This project provides a central approach to Color-related subjects on Wikipedia.
Please participate by editing the article, and help us assess and improve articles to good and 1.0 standards, or visit the wikiproject page for more details.
B This article has been rated as B-Class on the quality scale.
High This article has been rated as high-importance on the importance scale.

Article Grading:
The article has been rated for quality and/or importance but has no comments yet. If appropriate, please review the article and then leave comments here to identify the strengths and weaknesses of the article and what work it will need.

I corrected the green hsv values in the example part, as they were totally wrong in my eyes. --Abdull 22:32, 20 Mar 2005 (UTC)

Contents

[edit] More intuitive, etc.

As an artist, I find prefer the HSV space. I do not think the HSL is better or "more intuitive." Besides, intuiton can be wrong. Very light colors are not highly saturated! If the claim that HSL is better for artists is to remain, add some weasel words or quote someone.

[edit] HLS v. HSL

The title of this article is "HLS color space" but the content of the aticle uses HSL almost exculsively. Should this article be retitled to "HSL color space"? Given the similarities between the HSV colorspace and this colorspace, it seems like HSL is the more natural ordering of Hue, Saturation and Lightness.

Google shows more hits for HLS (79k vs. 65k) but it's almost even. I guess I don't see that it matters either way... Cburnett 17:02, 22 Mar 2005 (UTC)
I have myself never seen HLS used in that order in any application. --SuperBleda 14:59, 5 March 2006 (UTC)

[edit] HSL vs HSI

I can't find any difference between HSL and HSI, except the name of the axis. I'm redirecting HSI color space here. --minghong 09:26, 8 May 2005 (UTC)

They are not synonymous terms and there is a difference. HSL is a double cone from white to black; HSI is a since come from white at the peak. For example, see [1]. Cburnett 15:52, May 8, 2005 (UTC)
What I found is that both are double core. For both L and I, 0% is black and 100% is white [2] [3]. Am I wrong? It doesn't really matter which color is the "peak", right? The figure in your example is just flipped. --minghong 18:28, 8 May 2005 (UTC)
HSI is a single (the above "since" is a typo) cone. White is at the peak and black is at the center of the base (zero saturation of color with zero intensity = black; full itensity has no color so it is a single peak at white). Cburnett 04:30, May 9, 2005 (UTC)
No. HSI is double cone. It appears as double cone from what I've learnt, and numerous web references shows that it is a double cone just like HSL [4] [5] [6]. --minghong 05:23, 9 May 2005 (UTC)
It seems to me that the words "intensity" and "value" are synonymous and that, therefore, HSI should be synonymous with HSV, not HSL. -SharkD 03:54, 9 December 2006 (UTC)

[edit] HSL saturation formula?

According to the EasyRGB.com link at the bottom of this article (and several other sites) the HSL/HLS saturation is not ( 1 − min{R,G,B} ) but is based on the hexcone. I'd change it but I'm new to posting. :) --Kshakir 04:45, 2 September 2005 (UTC)

[edit] RGB to HSL formula && Accuracy Tag

Didn't work for me. What happens if L = 0? You get an impossibility. That can't be right (Bjorn Tipling 07:29, 29 March 2006 (UTC))

I fixed the formulas according to 'Fundamentals of Interactive Computer Graphics' by Foley and van Dam (see also [7]). Basically, MIN=MAX means the colour is grey, in which case H and S have no meaning, and L contains the shade of grey used. I am relatively new to wikipedia; does this mean the accuracy tag can be removed? -- Jan David Mol

Yes you can remove the edit tag or edit whatever you like or even add your own tags when you feel it's necessary (Here's a list of templates/tags). Thank you for contributing! It makes a lot more sense now. I have removed the tag. Also you may find it easier to sign your signatures by using (~~~~) This will generate an automated signature that other editors and click and be able to talk to you using your talk page and see your personal information page. (Bjorn Tipling 02:23, 30 March 2006 (UTC))

I fixed the formula so the first case for S is L==0, this came up when I implemented the function as code. If max==min then the result of the S math is 0 because the numerator of the fractions is zero so the special case shown before is meaningless. It is true that if you restrict yourself to >= 0 for the colors, then the only case where L==0 is also a case where max==min, but most other max==min cases will work in the other statements, and if you allow signed colors there are sets that will divide by zero when max != min.

[edit] HSL to RGB?

What is the method used for converting HSL to RGB? I would like to know. --Zemylat 19:43, 28 May 2006 (UTC)

[edit] HSL Color Sphere

I added an image of the HSL scheme mapped to a sphere. Though I think the image self-explanatory, I would appreciate it if someone were to add a description.SharkD 07:33, 20 October 2006 (UTC)

I created a 3D rendering of the color sphere. I'm not sure where to put it, so I'll just put it here. -SharkD 23:54, 22 October 2006 (UTC)

[edit] GIMP

GIMP actually uses both HSV and HSL. HSV in the colour picker, and HSL in Tools->Color Tools->Hue-Saturation (although the L component seems to be cut off - can't make it go too high or too low). I will move it to the right section.--Konstable 07:32, 18 February 2007 (UTC)

[edit] Color space or color model?

Is HSL a color space or a color model? Discuss. SharkD 23:02, 17 March 2007 (UTC)

Well, as I staked my claim on the article itself: I believe HSL is a color model, just as RGB is, though as with any color model there are a set of color spaces: for instance, there is an HSL color space mapped to the sRGB color space. Of course, more insight is welcome! Notinasnaid 23:12, 17 March 2007 (UTC)
Abstractly speaking, HSL and RGB are just two different ways of encoding a 3-dimensional 'space'. So until that space is anchored with some definition of what e.g. (R, G, B) = (0, 0.4, 1) means, both encodings are actually devoid of real-world meaning. It so happens that the RGB space is anchored by a generally accepted definition of what parameters R, G and B stand for (i.e. the albeit vague red, green, blue) so always worked 'well enough': HSL works equally well, being based on the same red, green, blue definitions. Still, in the days of analogue television different R,G or B phosphors gave very different characters to different display tubes. This is true today to a lesser extent, giving rise to the attempted 'sRGB' standard, and others with wider gamut.
I draw attention to the YUV article which correctly states

YUV is not an absolute color space. It is a way of encoding RGB information, and the actual color displayed depends on the actual RGB colorants used to display the signal. Therefore a value expressed as YUV is only predictable if standard RGB colorants are used (i.e. a fixed set of primary chromaticities, or particular set of red, green, and blue).

The same is true for any other colour model based on RGB, or indeed any other trichromatic means of representing colour. I think the introduction is clear enough in this respect. Just to complicate matters, as an example, if you based the HSL model on some reordering of conventional RGB, e.g. like BGR, then the actual colour represented by identical HSL values would be very different.
Similarly, choosing slightly (as opposed to drastically, in the previous example) different colorants for our R, G and B components, perhaps described in an ICC profile, would have a similar, although much subtler, effect.
Simon R 131.111.154.25 15:02, 4 April 2007 (UTC)
Retrieved from "http://en.wikipedia.org../../../h/s/l/Talk%7EHSL_color_space_eb68.html"