package hsluv

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package hsluv
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HSLuv and HPLuv color models as well as other common color spaces like RGB and XYZ, modeled as record types; provides conversion functions between the different color spaces and pretty-printers for all the color types.

Colors are represented as record types, to ensure that no mistakes converting between colors can be made.

In addition to the HSLuv and HPLuv color conversion functions, we also expose the color conversion functions that are used to implement the HSLuv and HPLuv conversions.

Further, pretty printers are included for the color types.

Types

type hsluv = {
  1. h : float;
  2. s : float;
  3. l : float;
}

hsluv represents the HSLuv color space, a human-friendly version of the HSL color model, where:

  • h is the hue component in degrees (0-360).
  • s is the saturation component as a percentage (0-100).
  • l is the lightness component as a percentage (0-100).

This color space aims to provide more uniform color distribution and is suitable for accurate color balancing.

type hpluv = {
  1. h : float;
  2. p : float;
  3. l : float;
}

hpluv represents the HPLuv color space, a variant of HSLuv with constant perceived lightness, where:

  • h is the hue component in degrees (0-360).
  • p is a measure of chroma (similar to saturation) as a percentage (0-100).
  • l is the lightness component as a percentage (0-100).

HPLuv is designed for applications requiring consistent perceptual lightness.

type rgb = {
  1. r : float;
  2. g : float;
  3. b : float;
}

rgb represents the RGB color space where:

  • r is the red component ranging from 0.0 to 1.0.
  • g is the green component ranging from 0.0 to 1.0.
  • b is the blue component ranging from 0.0 to 1.0.

This color space is commonly used in digital imaging.

type xyz = {
  1. x : float;
  2. y : float;
  3. z : float;
}

xyz represents the CIE 1931 XYZ color space where:

  • x is the X component.
  • y is the Y component, representing luminance.
  • z is the Z component.

This color space serves as a standard reference against which other color spaces are defined.

type luv = {
  1. l : float;
  2. u : float;
  3. v : float;
}

luv represents the CIE L*u*v* color space where:

  • l is the lightness component.
  • u and v are the color-opponent dimensions.

This color space is designed to be perceptually uniform with regard to human color vision.

type lch = {
  1. l : float;
  2. c : float;
  3. h : float;
}

lch represents the L*C*h color space, a cylindrical representation of the CIE L*a*b* color space, where:

  • l is the lightness component.
  • c is the chroma component.
  • h is the hue component in degrees (0-360).

This color space is useful for creating perceptually balanced color palettes.

Hsluv and Hpluv Color Conversion

val hsluv_to_hex : hsluv -> string

Converts HSLuv color space values to a hex color string. Example:

hsluv_to_hex {h = 260.0; s = 100.0; l = 50.0}
val hsluv_from_hex : string -> hsluv

Converts a hex color string to HSLuv color space values. Example:

hsluv_from_hex "#ff00ff"
val hsluv_to_rgb : hsluv -> rgb

Directly converts HSLuv color space values to RGB. Example:

hsluv_to_rgb {h = 260.0; s = 100.0; l = 50.0}
val hsluv_from_rgb : rgb -> hsluv

Converts RGB color space values to HSLuv. Example:

hsluv_from_rgb {r = 1.0; g = 0.0; b = 1.0}
val hpluv_to_hex : hpluv -> string

Converts HPLuv color space values to a hex color string. Example:

hpluv_to_hex {h = 260.0; p = 100.0; l = 50.0}
val hpluv_from_hex : string -> hpluv

Converts a hex color string to HPLuv color space values. Example:

hpluv_from_hex "#ff00ff"
val hpluv_to_rgb : hpluv -> rgb

Directly converts HPLuv color space values to RGB. Example:

hpluv_to_rgb {h = 260.0; p = 100.0; l = 50.0}
val hpluv_from_rgb : rgb -> hpluv

Converts RGB color space values to HPLuv. Example:

hpluv_from_rgb {r = 1.0; g = 0.0; b = 1.0}

Other Color Conversion Functions

val conv_xyz_luv : xyz -> luv

Converts XYZ color space values to Luv. Example:

conv_xyz_luv { x = 0.4124; y = 0.2126; z = 0.0193 }
val conv_luv_xyz : luv -> xyz

Converts Luv color space values to XYZ. Example:

conv_luv_xyz { l = 100.0; u = 0.0; v = 0.0 }
val conv_luv_lch : luv -> lch

Converts Luv color space values to LCh. Example:

conv_luv_lch { l = 100.0; u = 0.0; v = 0.0 }
val conv_lch_luv : lch -> luv

Converts LCh color space values to Luv. Example:

conv_lch_luv { l = 100.0; c = 0.0; h = 0.0 }
val conv_hsluv_lch : hsluv -> lch

Converts HSLuv color space values to LCh. Example:

conv_hsluv_lch { h = 360.0; s = 100.0; l = 100.0 }
val conv_lch_hsluv : lch -> hsluv

Converts LCh color space values to HSLuv. Example:

conv_lch_hsluv { l = 100.0; c = 100.0; h = 360.0 }
val conv_hpluv_lch : hpluv -> lch

Converts HPLuv color space values to LCh. Example:

conv_hpluv_lch { h = 360.0; p = 100.0; l = 100.0 }
val conv_lch_hpluv : lch -> hpluv

Converts LCh color space values to HPLuv. Example:

conv_lch_hpluv { l = 100.0; c = 100.0; h = 360.0 }
val conv_rgb_hex : rgb -> string

Converts RGB color space values to a hex color string. Example:

conv_rgb_hex { r = 1.0; g = 0.0; b = 0.0 }
val conv_hex_rgb : string -> rgb

Converts a hex color string to RGB color space values. Example:

conv_hex_rgb "#ff0000"
val conv_xyz_rgb : xyz -> rgb

Converts XYZ color space values to RGB. Example:

conv_xyz_rgb { x = 0.4124; y = 0.2126; z = 0.0193 }
val conv_rgb_xyz : rgb -> xyz

Converts RGB color space values to XYZ. Example:

conv_rgb_xyz { r = 1.0; g = 0.0; b = 0.0 }
val conv_lch_rgb : lch -> rgb

Converts LCh color space values to RGB. Example:

conv_lch_rgb { l = 100.0; c = 100.0; h = 360.0 }
val conv_rgb_lch : rgb -> lch

Converts RGB color space values to LCh. Example:

conv_rgb_lch { r = 1.0; g = 0.0; b = 0.0 }
val conv_hsluv_rgb : hsluv -> rgb

Converts HSLuv color space values to RGB. Example:

conv_hsluv_rgb { h = 360.0; s = 100.0; l = 100.0 }
val conv_rgb_hsluv : rgb -> hsluv

Converts RGB color space values to HSLuv. Example:

conv_rgb_hsluv { r = 1.0; g = 0.0; b = 0.0 }

Pretty-Printers

val pp_rgb : ?full_precision:bool -> Stdlib.Format.formatter -> rgb -> unit

Pretty-printer for RGB color values. Example:

let rgb_value = {r = 1.0; g = 0.5; b = 0.25} in
Printf.printf "RGB: %a\n" pp_rgb rgb_value
val pp_xyz : ?full_precision:bool -> Stdlib.Format.formatter -> xyz -> unit

Pretty-printer for XYZ color values. Example:

let xyz_value = {x = 0.5; y = 0.3; z = 0.2} in
Printf.printf "XYZ: %a\n" pp_xyz xyz_value
val pp_luv : ?full_precision:bool -> Stdlib.Format.formatter -> luv -> unit

Pretty-printer for LUV color values. Example:

let luv_value = {l = 70.0; u = 30.0; v = 40.0} in
Printf.printf "LUV: %a\n" pp_luv luv_value
val pp_lch : ?full_precision:bool -> Stdlib.Format.formatter -> lch -> unit

Pretty-printer for LCH color values. Example:

let lch_value = {l = 70.0; c = 30.0; h = 60.0} in
Printf.printf "LCH: %a\n" pp_lch lch_value
val pp_hsluv : ?full_precision:bool -> Stdlib.Format.formatter -> hsluv -> unit

Pretty-printer for HSLuv color values. Example:

let hsluv_value = {h = 120.0; s = 50.0; l = 70.0} in
Printf.printf "HSLuv: %a\n" pp_hsluv hsluv_value
val pp_hpluv : ?full_precision:bool -> Stdlib.Format.formatter -> hpluv -> unit

Pretty-printer for HPLuv color values. Example:

let hpluv_value = {h = 240.0; p = 50.0; l = 70.0} in
Printf.printf "HPLuv: %a\n" pp_hpluv hpluv_value