HSB vs HSL vs HSV

Question

I am making a Color class as a part of a very basic graphics API in c++. So I decided to take a look at Microsoft's .NET framework and noticed that their Color class has functions for HSB.

Then I started a research to determine whether I should provide HSB, HSL or HSV or ALL of them in my class.

So, I have 3 questions on HSB, HSL, HSV:

1. Is HSB same as HSL?

2. If not, why isn't there an HSBL or even HSBLV?

3. I find many different methods of calculating these values, can someone show me the FASTEST ones?

Answer 1

Is HSB same as HSL?

No, HSB is the same as HSV but HSL is different. All these are used as a friendly way to represent RGB colors. The Wikipedia article on HSL an HSV explains the differences using color cilinders: HSL and HSV Basically, Hue is the same for HSB and HSL but the Saturation takes different values and Brightness and Lightness are also different.

If not, why isn't there an HSBL or even HSBLV?

I don't get the point. Both HSB/HSV and HSL can represent any RGB color. Having B and L independently is not possible because of the way they are defined. A given HSB Brightness and Saturation is associated to a fixed Lightness. In fact converting between them is very easy.

I find many different methods of calculating these values, can someone show me the FASTEST ones?

There's a similar question here for calculating HSB from RGB: Fast, optimized and accurate RGB <-> HSB conversion code in C There's a Java implementation there that might help. For converting between HSB/HSV and HSL see HSL vs HSB vs HSV

Answer 2

Originally the difference between Brightness And Lightness Is. "Brightness" is used for Subtractive colors and "Lightness" for Additive colors. Now if your program is dealing with Subtractive colors like the CMYK system it is better to use HSB otherwise it is better HSL.