From 3b6f6b227a1bece25a4cd294121f898c3aeb5570 Mon Sep 17 00:00:00 2001 From: Julien Danjou Date: Mon, 22 Nov 2010 16:02:52 +0100 Subject: [PATCH] color-lab: new --- lisp/ChangeLog | 2 + lisp/color-lab.el | 241 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 243 insertions(+) create mode 100644 lisp/color-lab.el diff --git a/lisp/ChangeLog b/lisp/ChangeLog index 451abc48f..82847c2b4 100644 --- a/lisp/ChangeLog +++ b/lisp/ChangeLog @@ -1,5 +1,7 @@ 2010-11-22 Julien Danjou + * color-lab.el: New file. + * gnus-art.el (gnus-url-mailto): Do not downcase args. 2010-11-21 Andrew Cohen diff --git a/lisp/color-lab.el b/lisp/color-lab.el new file mode 100644 index 000000000..997bdbfc1 --- /dev/null +++ b/lisp/color-lab.el @@ -0,0 +1,241 @@ +;;; color-lab.el --- Color manipulation laboratory routines + +;; Copyright (C) 2010 Free Software Foundation, Inc. + +;; Author: Julien Danjou +;; Keywords: html + +;; This file is part of GNU Emacs. + +;; GNU Emacs is free software: you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; GNU Emacs is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with GNU Emacs. If not, see . + +;;; Commentary: + +;; This package provides color manipulation functions. + +;;; Code: + +(defun rgb->hsv (red green blue) + "Convert RED GREEN BLUE values to HSV representation. +Hue is in radian. Saturation and values are between 0 and 1." + (let* ((r (float red)) + (g (float green)) + (b (float blue)) + (max (max r g b)) + (min (min r g b))) + (list + (/ (* 2 float-pi + (cond ((and (= r g) (= g b)) 0) + ((and (= r max) + (>= g b)) + (* 60 (/ (- g b) (- max min)))) + ((and (= r max) + (< g b)) + (+ 360 (* 60 (/ (- g b) (- max min))))) + ((= max g) + (+ 120 (* 60 (/ (- b r) (- max min))))) + ((= max b) + (+ 240 (* 60 (/ (- r g) (- max min))))))) + 360) + (if (= max 0) + 0 + (- 1 (/ min max))) + (/ max 255.0)))) + +(defun rgb->hsl (red green blue) + "Convert RED GREEN BLUE colors to their HSL representation. +RED, GREEN and BLUE must be between 0 and 255." + (let* ((r (/ red 255.0)) + (g (/ green 255.0)) + (b (/ blue 255.0)) + (max (max r g b)) + (min (min r g b)) + (delta (- max min)) + (l (/ (+ max min) 2.0))) + (list + (if (= max min) + 0 + (* 2 float-pi + (/ (cond ((= max r) + (+ (/ (- g b) delta) (if (< g b) 6 0))) + ((= max g) + (+ (/ (- b r) delta) 2)) + (t + (+ (/ (- r g) delta) 4))) + 6))) + (if (= max min) + 0 + (if (> l 0.5) + (/ delta (- 2 (+ max min))) + (/ delta (+ max min)))) + l))) + +(defun rgb->xyz (red green blue) + "Converts RED GREEN BLUE colors to CIE XYZ representation. +RED, BLUE and GREEN must be between 0 and 1." + (let ((r (if (<= red 0.04045) + (/ red 12.95) + (expt (/ (+ red 0.055) 1.055) 2.4))) + (g (if (<= green 0.04045) + (/ green 12.95) + (expt (/ (+ green 0.055) 1.055) 2.4))) + (b (if (<= blue 0.04045) + (/ blue 12.95) + (expt (/ (+ blue 0.055) 1.055) 2.4)))) + (list (+ (* 0.4124564 r) (* 0.3575761 g) (* 0.1804375 b)) + (+ (* 0.21266729 r) (* 0.7151522 g) (* 0.0721750 b)) + (+ (* 0.0193339 r) (* 0.1191920 g) (* 0.9503041 b))))) + +(defun xyz->rgb (X Y Z) + "Converts CIE XYZ colors to RGB." + (let ((r (+ (* 3.2404542 X) (* -1.5371385 Y) (* -0.4985314 Z))) + (g (+ (* -0.9692660 X) (* 1.8760108 Y) (* 0.0415560 Z))) + (b (+ (* 0.0556434 X) (* -0.2040259 Y) (* 1.0572252 Z)))) + (list (if (<= r 0.0031308) + (* 12.92 r) + (- (* 1.055 (expt r (/ 1 2.4))) 0.055)) + (if (<= g 0.0031308) + (* 12.92 g) + (- (* 1.055 (expt g (/ 1 2.4))) 0.055)) + (if (<= b 0.0031308) + (* 12.92 b) + (- (* 1.055 (expt b (/ 1 2.4))) 0.055))))) + +(defconst color-lab-d65-xyz '(0.950455 1.0 1.088753) + "D65 white point in CIE XYZ.") + +(defconst color-lab-ε (/ 216 24389.0)) +(defconst color-lab-κ (/ 24389 27.0)) + +(defun xyz->lab (X Y Z &optional white-point) + "Converts CIE XYZ to CIE L*a*b*. +WHITE-POINT can be specified as (X Y Z) white point to use. If +none is set, `color-lab-d65-xyz' is used." + (destructuring-bind (Xr Yr Zr) (or white-point color-lab-d65-xyz) + (let* ((xr (/ X Xr)) + (yr (/ Y Yr)) + (zr (/ Z Zr)) + (fx (if (> xr color-lab-ε) + (expt xr (/ 1 3.0)) + (/ (+ (* color-lab-κ xr) 16) 116.0))) + (fy (if (> yr color-lab-ε) + (expt yr (/ 1 3.0)) + (/ (+ (* color-lab-κ yr) 16) 116.0))) + (fz (if (> zr color-lab-ε) + (expt zr (/ 1 3.0)) + (/ (+ (* color-lab-κ zr) 16) 116.0)))) + (list + (- (* 116 fy) 16) ; L + (* 500 (- fx fy)) ; a + (* 200 (- fy fz)))))) ; b + +(defun lab->xyz (L a b &optional white-point) + "Converts CIE L*a*b* to CIE XYZ. +WHITE-POINT can be specified as (X Y Z) white point to use. If +none is set, `color-lab-d65-xyz' is used." + (destructuring-bind (Xr Yr Zr) (or white-point color-lab-d65-xyz) + (let* ((fy (/ (+ L 16) 116.0)) + (fz (- fy (/ b 200.0))) + (fx (+ (/ a 500.0) fy)) + (xr (if (> (expt fx 3) color-lab-ε) + (expt fx 3) + (/ (- (* fx 116) 16) color-lab-κ))) + (yr (if (> L (* color-lab-κ color-lab-ε)) + (expt (/ (+ L 16) 116.0) 3) + (/ L color-lab-κ))) + (zr (if (> (expt fz 3) color-lab-ε) + (expt fz 3) + (/ (- (* 116 fz) 16) color-lab-κ)))) + (list (* xr Xr) ; X + (* yr Yr) ; Y + (* zr Zr))))) ; Z + +(defun rgb->lab (red green blue) + "Converts RGB to CIE L*a*b*." + (apply 'xyz->lab (rgb->xyz red green blue))) + +(defun rgb->normalize (color) + "Normalize a RGB color to values between [0,1]." + (mapcar (lambda (x) (/ x 65535.0)) (x-color-values color))) + +(defun lab->rgb (L a b) + "Converts CIE L*a*b* to RGB." + (apply 'xyz->rgb (lab->xyz L a b))) + +(defun color-lab-ciede2000 (color1 color2 &optional kL kC kH) + "Computes the CIEDE2000 color distance between COLOR1 and COLOR2. +Colors must be in CIE L*a*b* format." + (destructuring-bind (L₁ a₁ b₁) color1 + (destructuring-bind (L₂ a₂ b₂) color2 + (let* ((kL (or kL 1)) + (kC (or kC 1)) + (kH (or kH 1)) + (C₁ (sqrt (+ (expt a₁ 2) (expt b₁ 2)))) + (C₂ (sqrt (+ (expt a₂ 2) (expt b₂ 2)))) + (C̄ (/ (+ C₁ C₂) 2.0)) + (G (* 0.5 (- 1 (sqrt (/ (expt C̄ 7) (+ (expt C̄ 7) (expt 25 7))))))) + (a′₁ (* (+ 1 G) a₁)) + (a′₂ (* (+ 1 G) a₂)) + (C′₁ (sqrt (+ (expt a′₁ 2) (expt b₁ 2)))) + (C′₂ (sqrt (+ (expt a′₂ 2) (expt b₂ 2)))) + (h′₁ (if (and (= b₁ 0) (= a′₁ 0)) + 0 + (let ((v (atan b₁ a′₁))) + (if (< v 0) + (+ v (* 2 float-pi)) + v)))) + (h′₂ (if (and (= b₂ 0) (= a′₂ 0)) + 0 + (let ((v (atan b₂ a′₂))) + (if (< v 0) + (+ v (* 2 float-pi)) + v)))) + (ΔL′ (- L₂ L₁)) + (ΔC′ (- C′₂ C′₁)) + (Δh′ (cond ((= (* C′₁ C′₂) 0) + 0) + ((<= (abs (- h′₂ h′₁)) float-pi) + (- h′₂ h′₁)) + ((> (- h′₂ h′₁) float-pi) + (- (- h′₂ h′₁) (* 2 float-pi))) + ((< (- h′₂ h′₁) (- float-pi)) + (+ (- h′₂ h′₁) (* 2 float-pi))))) + (ΔH′ (* 2 (sqrt (* C′₁ C′₂)) (sin (/ Δh′ 2.0)))) + (L̄′ (/ (+ L₁ L₂) 2.0)) + (C̄′ (/ (+ C′₁ C′₂) 2.0)) + (h̄′ (cond ((= (* C′₁ C′₂) 0) + (+ h′₁ h′₂)) + ((<= (abs (- h′₁ h′₂)) float-pi) + (/ (+ h′₁ h′₂) 2.0)) + ((< (+ h′₁ h′₂) (* 2 float-pi)) + (/ (+ h′₁ h′₂ (* 2 float-pi)) 2.0)) + ((>= (+ h′₁ h′₂) (* 2 float-pi)) + (/ (+ h′₁ h′₂ (* -2 float-pi)) 2.0)))) + (T (+ 1 + (- (* 0.17 (cos (- h̄′ (degrees-to-radians 30))))) + (* 0.24 (cos (* h̄′ 2))) + (* 0.32 (cos (+ (* h̄′ 3) (degrees-to-radians 6)))) + (- (* 0.20 (cos (- (* h̄′ 4) (degrees-to-radians 63))))))) + (Δθ (* (degrees-to-radians 30) (exp (- (expt (/ (- h̄′ (degrees-to-radians 275)) (degrees-to-radians 25)) 2))))) + (Rc (* 2 (sqrt (/ (expt C̄′ 7) (+ (expt C̄′ 7) (expt 25 7)))))) + (Sl (+ 1 (/ (* 0.015 (expt (- L̄′ 50) 2)) (sqrt (+ 20 (expt (- L̄′ 50) 2)))))) + (Sc (+ 1 (* C̄′ 0.045))) + (Sh (+ 1 (* 0.015 C̄′ T))) + (Rt (- (* (sin (* Δθ 2)) Rc)))) + (sqrt (+ (expt (/ ΔL′ (* Sl kL)) 2) + (expt (/ ΔC′ (* Sc kC)) 2) + (expt (/ ΔH′ (* Sh kH)) 2) + (* Rt (/ ΔC′ (* Sc kC)) (/ ΔH′ (* Sh kH))))))))) + +(provide 'color-lab) -- 2.34.1