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use num_traits::{Float, clamp}; use rgb::Rgb; use lab::Lab; #[derive(Debug, Copy, Clone, PartialOrd, PartialEq, Hash, Default)] pub struct Xyz<T: Float = f32> { pub data: [T; 3] } impl<T: Float> Xyz<T> { pub fn new(x: T, y: T, z: T) -> Self { Xyz { data: [x, y, z] } } pub fn from_rgb(rgb: Rgb) -> Self { rgb.to_xyz() } pub fn from_lab(lab: Lab<T>) -> Self { lab.to_xyz() } pub fn to_rgb(self) -> Rgb { let one_hundred = T::from(100.0).unwrap(); let x = self.data[0] / one_hundred; let y = self.data[1] / one_hundred; let z = self.data[2] / one_hundred; let r = x * T::from(3.2406).unwrap() + y * T::from(-1.5372).unwrap() + z * T::from(-0.4986).unwrap(); let g = x * T::from(-0.9689).unwrap() + y * T::from(1.8758).unwrap() + z * T::from(0.0415).unwrap(); let b = x * T::from(0.0557).unwrap() + y * T::from(-0.2040).unwrap() + z * T::from(1.0570).unwrap(); let r = pivot_xyz_rgb(r); let g = pivot_xyz_rgb(g); let b = pivot_xyz_rgb(b); let zero = T::zero(); let max_u8 = T::from(255.0).unwrap(); Rgb { data: [ clamp(r * max_u8, zero, max_u8).to_u8().unwrap(), clamp(g * max_u8, zero, max_u8).to_u8().unwrap(), clamp(b * max_u8, zero, max_u8).to_u8().unwrap(), ] } } pub fn to_lab(self) -> Lab<T> { let white_ref = [ T::from(95.047).unwrap(), T::from(100.000).unwrap(), T::from(108.883).unwrap(), ]; let x = pivot_xyz_lab(self.data[0] / white_ref[0]); let y = pivot_xyz_lab(self.data[1] / white_ref[1]); let z = pivot_xyz_lab(self.data[2] / white_ref[2]); Lab { l: (T::from(116.0).unwrap() * y - T::from(16.0).unwrap()).max(T::from(0.0).unwrap()), a: T::from(500.0).unwrap() * (x - y), b: T::from(200.0).unwrap() * (y - z) } } } impl<T: Float> From<Lab<T>> for Xyz<T> { fn from(lab: Lab<T>) -> Self { Xyz::from_lab(lab) } } impl<T: Float> From<Rgb> for Xyz<T> { fn from(rgb: Rgb) -> Self { Xyz::from_rgb(rgb) } } fn pivot_xyz_rgb<T: Float>(n: T) -> T { if n > T::from(0.0031308).unwrap() { T::from(1.055).unwrap() * n.powf(T::from(1.0).unwrap() / T::from(2.4).unwrap()) - T::from(0.055).unwrap() } else { n * T::from(12.92).unwrap() } } fn cubic_root<T: Float>(n: T) -> T { n.powf(T::from(1.0).unwrap() / T::from(3.0).unwrap()) } fn pivot_xyz_lab<T: Float>(n: T) -> T { let epsilon = T::from(0.008856).unwrap(); let kappa = T::from(903.3).unwrap(); if n > epsilon { cubic_root(n) } else { (kappa * n + T::from(16.0).unwrap()) / T::from(116.0).unwrap() } } #[cfg(test)] mod tests { use lab::Lab; use rgb::Rgb; use xyz::Xyz; #[test] fn rgb_to_xyz_simple() { let rgb = Rgb { data: [50, 50, 50] }; let xyz: Xyz = rgb.into(); assert_eq!(xyz.data[0], 3.0317173); assert_eq!(xyz.data[1], 3.1896026); assert_eq!(xyz.data[2], 3.4734776); } #[test] fn rgb_to_xyz_difficult() { let rgb = Rgb { data: [43, 21, 8] }; let xyz: Xyz = rgb.into(); assert_eq!(xyz.data[0], 1.3082554); assert_eq!(xyz.data[1], 1.0674537); assert_eq!(xyz.data[2], 0.3668146); } #[test] fn xyz_to_rgb_simple() { let xyz = Xyz { data: [33.113681223365006, 15.997065707552856, 50.057654344067586] }; let rgb: Rgb = xyz.into(); assert_eq!(rgb.data[0], 200); assert_eq!(rgb.data[1], 0); assert_eq!(rgb.data[2], 190); } #[test] fn xyz_to_lab_simple() { let xyz = Xyz { data: [33.113681223365006, 15.997065707552856, 50.057654344067586] }; let lab: Lab = xyz.into(); assert_eq!(lab.l, 46.97064); assert_eq!(lab.a, 80.399574); assert_eq!(lab.b, -45.789467); } #[test] fn xyz_to_lab_simple2() { let xyz = Xyz { data: [1.0590637931500604, 0.840998318832299, 0.22137415400510363] }; let lab: Lab = xyz.into(); assert_eq!(lab.l, 7.596737); assert_eq!(lab.a, 9.967141); assert_eq!(lab.b, 9.931389); } }