ArtRage 5 Product PageArtRage Lite Product PageArtRage for iPad Product PageArtRage for Android Product PageArtRage  Android Oil Painter Free Product PageArtRage  Free Demos Page

Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Wrong colour picker values? HSL vs. HSB

  1. #1
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238

    Exclamation Wrong colour picker values? HSL vs. HSB


    Let's just start with this picture. It shows how a single white colour was given two totally different Saturation values. In fact, white would NEVER be 100% saturate in HSB system.



    Conclusion:
    AR uses the term Luminance in the way of Brightness. But it resulted in a 100% saturated white which doesn't exist in HSB system. In HSB, the colour with 100% S and 100% B is always the purest colour like this.
    Attached Images Attached Images  
    Last edited by gb_whisper; 03-22-2011 at 08:06 AM.

  2. #2
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238
    So there must be a coding error for all the colours. Now let's check on this.

    The attached image below shows how the "Precise Colour Picker" works compared to Photoshop. Since the upper right edge of this picker has 100% S value for all of the colours, a white tint of orange has 100% Saturation as well- which is wrong.

    I think in AR 'Saturation' refers to 'Chroma'.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	p1.jpg 
Views:	104 
Size:	180.8 KB 
ID:	53863  
    Last edited by gb_whisper; 03-22-2011 at 08:08 AM.

  3. #3
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238
    The same problem can be seen from all colours.

    The attached picture shows how a more saturated colour was treated as less saturated.

    A colour rich in white = more saturated? It is so wrong.

    And then I realized the serious problem with the design of the fan-shaped colour picker.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	p3.jpg 
Views:	95 
Size:	407.0 KB 
ID:	53864  
    Last edited by gb_whisper; 03-22-2011 at 02:34 AM.

  4. #4
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238
    Since we are artists and we don't really need LSH numbers when we pick colours.

    The fan-shaped colour picker is designed based on the Precise Colour Picker. Since the L and S values are wrong (edited: not wrong. See HSV & HSL difference), the fan shape is stretched in a wrong way. It's max Saturation value is not located in corner or entire edge of the picker.
    Attached Images Attached Images  
    Last edited by gb_whisper; 03-22-2011 at 08:12 AM.

  5. #5
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238
    You might think why that matters. Don't we just pick the colour we see? Why does the shape of the colour picker matter?

    For digital artists, numbers are really important. By reducing Saturation (with other values unchanged) we get a colour with less saturation. On Photoshop's square colour picker, you can change only one value when you move your cursor horizontally (for saturation) or vertically (for brightness), which is quite easy to understand. On Painter's colour picker, you can move your cursor towards any one corner of the triangle to get your desired colour.

    AR's fan-shaped colour picker should work in theory, since it still contains 4 edges (like a square colour picker). When you want to change only L or S (take the LS/H picker for example), you should simply move your cursor in a circle curve to gain the same 'moving horizontally' effect in Photoshop.

    However, as I mentioned, the L and S values are wrong so the palette is stretched in a wrong way. There is now no way to know the accurate Saturation value by seeing from the colour picker. The saturation value is somehow arranged in a reverse way in lighter tones. You just don't know how to move your mouse!
    Attached Images Attached Images  
    Last edited by gb_whisper; 03-22-2011 at 07:02 AM.

  6. #6
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238
    So I really think AR team should rework on this.

    I am amazed I had never noticed this before. But when I compare all the AR colour data with Photoshop I realized this problem. The last picture compares the AR LSH slider with PS and PT.

    Also, although it might not be true, but I really don't think anyone would ever use those RGB pickers. LH/S and HS/L picker somehow works but seems silly. This is just my personal opinion.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	p4.jpg 
Views:	72 
Size:	194.8 KB 
ID:	53867  
    Last edited by gb_whisper; 03-22-2011 at 07:27 AM.

  7. #7
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238
    Quote Originally Posted by henrystaahle View Post
    I have just finished studying colour sampling in some of my paint applications. First I drew a rectangle in a vector program noting the RGB-values. Then I opened that png file in ArtRage, Painter and Photoshop and noted that all returned the same RGB values as the original. All three returned the same answer.
    Yeah, but you don't use RGB colour picker/slider for digital painting, do you?

    Of course RGB values are the same. I am talking HSB or this HSL in AR. Not many other programs use HSL together with a fan shaped colour picker.
    Last edited by gb_whisper; 03-22-2011 at 07:50 AM.

  8. #8
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238

    Now I know what happened...

    I found this from wikipedia. Here is the quote:


    ...while "hue" in HSL and HSV refers to the same attribute, their definitions of "saturation" differ dramatically.

    Because these definitions of saturation in which very dark (in both models) or very light (in HSL) near-neutral colors, for instance   or  , are considered fully saturated conflict with the intuitive notion of color purity, often a conic or bi-conic solid is drawn instead, with what this article calls chroma as its radial dimension, instead of saturation. Confusingly, such diagrams usually label this radial dimension "saturation", blurring or erasing the distinction between saturation and chroma.
    So AR is not wrong... But I still wish AR could use HSB instead of HSL, as I do think white tints are not 100% saturated colours. "White drops saturation down"- that's what I learned from other painters.
    Last edited by gb_whisper; 03-22-2011 at 07:57 AM.

  9. #9
    Join Date
    Nov 2007
    Location
    UK
    Posts
    238
    Quote Originally Posted by henrystaahle View Post
    I don't care much if the look of the colour picker is fan, circle, square or triangle as long as it works properly. I think AR's fan style does. But it can be discussed if it is the best design. I compare it to Painter's and I find AR very good for me.

    Of course I use RGB colour picker/slider while painting (my Painters colour wheel is RGB). But I really don't care if it is this or that as long as I get the result I want.
    So if your want a gray colour, you put all 3 RGB values the same... interesting. But as I said, we don't really need whatever sliders for digital painting; We just pick the colour we want as long as there is a colour picker. You are right about it.

    But you know, a spider shaped or a star shaped colour picker can be really annoying.

    For people who want to know what's happening to their paints, I think those data is still useful. Like I simply want a more saturated shadow for skin, but AR says its chroma should be lowered as well (for those white tints)... I was like: What are you talking about? The appliacation of Chroma is not as easy as Saturation for me. So I think it is a good suggestion for AR team. Or they can just ignore me, because people either don't know about it or are quite happy with it.
    Last edited by gb_whisper; 03-22-2011 at 08:51 AM.

  10. #10
    Join Date
    Apr 2007
    Location
    washington, usa
    Posts
    14,215
    GB,

    I think what you are looking for is the HL/S model for both the color picker and the precise color picker. I think that will give you what you are looking for.

    the letter after the slash refers to the variable feature, in this case it is
    saturation. the other legs stay the same when selecting a different saturation by clicking in the little bar in the middle of the precise color picker or the bar that spans the top of the color picker.

    if you select HS/L then the variable is luminance in the color bar.

    if you select LS/H then the variable is the hue.

    I agree with Henry. ar3 has the best color pickers out there.
    Attached Images Attached Images   
    Last edited by screenpainter; 03-22-2011 at 09:20 AM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •