Fairchild (2005), pp. 83–93 Fairchild, Mark D. (2005). Color Appearance Models (2nd ed.). Addison-Wesley. This book doesn't discuss HSL or HSV specifically, but is one of the most readable and precise resources about current color science.
Rafael C. Gonzalez and Richard Eugene Woods (2008). Digital Image Processing, 3rd ed. Upper Saddle River, NJ: Prentice Hall. ISBN0-13-168728-X. pp. 407–413.
For instance, a tool in Illustrator CS4, and Adobe's related web tool, Kuler, both allow users to define color schemes based on HSV relationships, but with a hue circle modified to better match the RYB model used traditionally by painters. The web tools ColorJack, Color Wizard, and ColorBlender all pick color schemes with reference to HSL or HSV.
For instance, a tool in Illustrator CS4, and Adobe's related web tool, Kuler, both allow users to define color schemes based on HSV relationships, but with a hue circle modified to better match the RYB model used traditionally by painters. The web tools ColorJack, Color Wizard, and ColorBlender all pick color schemes with reference to HSL or HSV.
For instance, a tool in Illustrator CS4, and Adobe's related web tool, Kuler, both allow users to define color schemes based on HSV relationships, but with a hue circle modified to better match the RYB model used traditionally by painters. The web tools ColorJack, Color Wizard, and ColorBlender all pick color schemes with reference to HSL or HSV.
In the Joblove and Greenberg (1978) paper first introducing HSL, they called HSL lightness "intensity", called HSL saturation "relative chroma", called HSV saturation "saturation" and called HSV value "value". They carefully and unambiguously described and compared three models: hue/chroma/intensity, hue/relative chroma/intensity, and hue/value/saturation. Unfortunately, later authors were less fastidious, and current usage of these terms is inconsistent and often misleading. Joblove, George H.; Greenberg, Donald (August 1978). "Color spaces for computer graphics"(PDF). Computer Graphics. 12 (3): 20–25. doi:10.1145/965139.807362. Joblove and Greenberg's paper was the first describing the HSL model, which it compares to HSV.
Using the chroma here not only agrees with the original Joblove and Greenberg (1978) paper, but is also in the proper spirit of the psychometric definition of the term. Some models call this attribute saturation – for instance Adobe Photoshop's "Saturation" blend mode – but such use is even more confusing than the use of the term in HSL or HSV, especially when two substantially different definitions are used side by side. Joblove, George H.; Greenberg, Donald (August 1978). "Color spaces for computer graphics"(PDF). Computer Graphics. 12 (3): 20–25. doi:10.1145/965139.807362. Joblove and Greenberg's paper was the first describing the HSL model, which it compares to HSV.
In the Joblove and Greenberg (1978) paper first introducing HSL, they called HSL lightness "intensity", called HSL saturation "relative chroma", called HSV saturation "saturation" and called HSV value "value". They carefully and unambiguously described and compared three models: hue/chroma/intensity, hue/relative chroma/intensity, and hue/value/saturation. Unfortunately, later authors were less fastidious, and current usage of these terms is inconsistent and often misleading. Joblove, George H.; Greenberg, Donald (August 1978). "Color spaces for computer graphics"(PDF). Computer Graphics. 12 (3): 20–25. doi:10.1145/965139.807362. Joblove and Greenberg's paper was the first describing the HSL model, which it compares to HSV.
In Levkowitz and Herman's formulation, R, G, and B stand for the voltages on the guns of a CRT display, which might have different maxima, and so their cartesian gamut could be a box of any unequal dimensions. Other definitions commonly use integer values in the range [0, 255], storing the value for each component in one byte. We define the RGB gamut to be a unit cube for convenience because it simplifies and clarifies the math. Also, in general, HSL and HSV are today computed directly from gamma-correctedR′, G′, and B′ – for instance in sRGB space – but, when the models were developed, might have been transformations of a linear RGB space. Early authors don't address gamma correction at all, except Alvy Ray Smith[10] who clearly states that "We shall assume that an RGB monitor is a linear device", and thus designed HSV using linear RGB. We will drop the primes, and the labels R, G, and B should be taken to stand for the three attributes of the origin RGB space, whether or not it is gamma corrected. Levkowitz, Haim; Herman, Gabor T. (1993). "GLHS: A Generalized Lightness, Hue and Saturation Color Model". CVGIP: Graphical Models and Image Processing. 55 (4): 271–285. doi:10.1006/cgip.1993.1019. This paper explains how both HSL and HSV, as well as other similar models, can be thought of as specific variants of a more general "GLHS" model. Levkowitz and Herman provide pseudocode for converting from RGB to GLHS and back.
Using the chroma here not only agrees with the original Joblove and Greenberg (1978) paper, but is also in the proper spirit of the psychometric definition of the term. Some models call this attribute saturation – for instance Adobe Photoshop's "Saturation" blend mode – but such use is even more confusing than the use of the term in HSL or HSV, especially when two substantially different definitions are used side by side. Joblove, George H.; Greenberg, Donald (August 1978). "Color spaces for computer graphics"(PDF). Computer Graphics. 12 (3): 20–25. doi:10.1145/965139.807362. Joblove and Greenberg's paper was the first describing the HSL model, which it compares to HSV.
Levkowitz and Herman (1993) Levkowitz, Haim; Herman, Gabor T. (1993). "GLHS: A Generalized Lightness, Hue and Saturation Color Model". CVGIP: Graphical Models and Image Processing. 55 (4): 271–285. doi:10.1006/cgip.1993.1019. This paper explains how both HSL and HSV, as well as other similar models, can be thought of as specific variants of a more general "GLHS" model. Levkowitz and Herman provide pseudocode for converting from RGB to GLHS and back.
N. Magnetat-Thalmann; N. Chourot; D. Thalmann (March 1984). "Colour Gradation, Shading and Texture Using a Limited Terminal". Computer Graphics Forum. 3: 83–90. doi:10.1111/j.1467-8659.1984.tb00092.x. S2CID29541525.
The original patent on this idea was by Georges Valensi in 1938: FR patent 841335, Valensi, Georges, "Procédé de télévision en couleurs", published 1939-05-17, issued 1939-02-06US patent 2375966, Valensi, Georges, "System of television in colors", published 1945-05-15
For a more specific discussion of the term luma, see Charles Poynton (2008). See also RGB color space#Specifications. Photoshop exclusively uses the NTSC coefficients for its "Luminosity" blend mode regardless of the RGB color space involved.[27] Poynton, Charles (2008). "YUV and luminance considered harmful". poynton.com. Retrieved August 30, 2017.
Most of the disadvantages below are listed in Poynton (1997), though as mere statements, without examples. Poynton, Charles (1997). "Frequently Asked Questions About Color". poynton.com. This self-published frequently asked questions page, by digital video expert Charles Poynton, explains, among other things, why in his opinion these models "are useless for the specification of accurate color", and should be abandoned in favor of more psychometrically relevant models.
Poynton (1997) Poynton, Charles (1997). "Frequently Asked Questions About Color". poynton.com. This self-published frequently asked questions page, by digital video expert Charles Poynton, explains, among other things, why in his opinion these models "are useless for the specification of accurate color", and should be abandoned in favor of more psychometrically relevant models.
Poynton (1997). "What are HSB and HLS?" Poynton, Charles (1997). "Frequently Asked Questions About Color". poynton.com. This self-published frequently asked questions page, by digital video expert Charles Poynton, explains, among other things, why in his opinion these models "are useless for the specification of accurate color", and should be abandoned in favor of more psychometrically relevant models.
Hanbury, Allan (2003). Circular Statistics Applied to Colour Images. 8th Computer Vision Winter Workshop. CiteSeerX10.1.1.4.1381.
personal.psu.edu
Brewer, Cynthia A. (1999). "Color Use Guidelines for Data Representation". Proceedings of the Section on Statistical Graphics. Alexandria, VA: American Statistical Association. pp. 55–60. Archived from the original on 2009-08-07. Retrieved 2010-02-05.
Fairchild (2005), pp. 83–93 Fairchild, Mark D. (2005). Color Appearance Models (2nd ed.). Addison-Wesley. This book doesn't discuss HSL or HSV specifically, but is one of the most readable and precise resources about current color science.
N. Magnetat-Thalmann; N. Chourot; D. Thalmann (March 1984). "Colour Gradation, Shading and Texture Using a Limited Terminal". Computer Graphics Forum. 3: 83–90. doi:10.1111/j.1467-8659.1984.tb00092.x. S2CID29541525.
Brewer, Cynthia A. (1999). "Color Use Guidelines for Data Representation". Proceedings of the Section on Statistical Graphics. Alexandria, VA: American Statistical Association. pp. 55–60. Archived from the original on 2009-08-07. Retrieved 2010-02-05.
