From: Christian <info@xxxxxxxxxxxxxxxx> Date: Sun, 31 May 2009 17:53:43 +0200 Hi Michael The HSL is one of the best color models. The colors are symmetrical ordered. Advantages 1. symmetrical 2. color values are not rounded (you have more colors than in the HEX model) 3. logical (no senselessly black axis) 4. equidistant colors in the color picker 5. the right color theory. In the middle is the neutral gray [1] Bad's in the HSV color picker 1. not symmetrical 2. color values are rounded (in HEX a base color can have only a value of 0 - 255) 3. not logical (a senselessly black axis) 4. not equidistant colors in the color picker, you can click too many colors in the black area. 5. the color circle is correct but in the middle is not the neutral gray. I favor HSL also, and it's what we use in Gutenprint to perform correction (actually, we perform parts of it in HL+G, but that amounts to the same thing). I also added HSL decomposition to GIMP several years ago, and find it very useful -- a simple manipulation of the L curve can have a dramatic and predictable effect on the image. L conforms much more closely to perception than V, which is a major advantage when lightening or darkening an image -- in HSV space, there's no simple way to do that. I'd ideally like to see an HSL-based correction pack in GIMP using the Gutenprint algorithm, where it's possible to correct all three channels as a single operation. The correction adjustments (+/- delta for H, multiplicative factors with soft clipping for S and L) are done with curves, where the X axis is the starting hue and the Y axis is the correction. This would allow selective hue shifting along with saturation and lightness adjustments in one shot, with only one loss of precision. -- Robert Krawitz <rlk@xxxxxxxxxxxx> Tall Clubs International -- http://www.tall.org/ or 1-888-IM-TALL-2 Member of the League for Programming Freedom -- mail lpf@xxxxxxxxxxxx Project lead for Gutenprint -- http://gimp-print.sourceforge.net "Linux doesn't dictate how I work, I dictate how Linux works." --Eric Crampton _______________________________________________ Gimp-developer mailing list Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer
