-;;; color-lab.el --- Color manipulation laboratory routines -*- coding: utf-8; -*-
+;;; color.el --- Color manipulation laboratory routines -*- coding: utf-8; -*-
;; Copyright (C) 2010 Free Software Foundation, Inc.
(unless (boundp 'float-pi)
(defconst float-pi (* 4 (atan 1)) "The value of Pi (3.1415926...).")))
-(defun rgb->hsv (red green blue)
+(defun color-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))
(- 1 (/ min max)))
(/ max 255.0))))
-(defun rgb->hsl (red green blue)
+(defun color-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))
(/ delta (+ max min))))
l)))
-(defun rgb->xyz (red green blue)
+(defun color-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)
(+ (* 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."
+(defun color-xyz->rgb (X Y Z)
+ "Converts CIE X Y Z 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))))
(* 12.92 b)
(- (* 1.055 (expt b (/ 1 2.4))) 0.055)))))
-(defconst color-lab-d65-xyz '(0.950455 1.0 1.088753)
+(defconst color-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))
+(defconst color-cie-ε (/ 216 24389.0))
+(defconst color-cie-κ (/ 24389 27.0))
-(defun xyz->lab (X Y Z &optional white-point)
+(defun color-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)
+none is set, `color-d65-xyz' is used."
+ (destructuring-bind (Xr Yr Zr) (or white-point color-d65-xyz)
(let* ((xr (/ X Xr))
(yr (/ Y Yr))
(zr (/ Z Zr))
- (fx (if (> xr color-lab-ε)
+ (fx (if (> xr color-cie-ε)
(expt xr (/ 1 3.0))
- (/ (+ (* color-lab-κ xr) 16) 116.0)))
- (fy (if (> yr color-lab-ε)
+ (/ (+ (* color-cie-κ xr) 16) 116.0)))
+ (fy (if (> yr color-cie-ε)
(expt yr (/ 1 3.0))
- (/ (+ (* color-lab-κ yr) 16) 116.0)))
- (fz (if (> zr color-lab-ε)
+ (/ (+ (* color-cie-κ yr) 16) 116.0)))
+ (fz (if (> zr color-cie-ε)
(expt zr (/ 1 3.0))
- (/ (+ (* color-lab-κ zr) 16) 116.0))))
+ (/ (+ (* color-cie-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)
+(defun color-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)
+none is set, `color-d65-xyz' is used."
+ (destructuring-bind (Xr Yr Zr) (or white-point color-d65-xyz)
(let* ((fy (/ (+ L 16) 116.0))
(fz (- fy (/ b 200.0)))
(fx (+ (/ a 500.0) fy))
- (xr (if (> (expt fx 3.0) color-lab-ε)
+ (xr (if (> (expt fx 3.0) color-cie-ε)
(expt fx 3.0)
- (/ (- (* fx 116) 16) color-lab-κ)))
- (yr (if (> L (* color-lab-κ color-lab-ε))
+ (/ (- (* fx 116) 16) color-cie-κ)))
+ (yr (if (> L (* color-cie-κ color-cie-ε))
(expt (/ (+ L 16) 116.0) 3.0)
- (/ L color-lab-κ)))
- (zr (if (> (expt fz 3) color-lab-ε)
+ (/ L color-cie-κ)))
+ (zr (if (> (expt fz 3) color-cie-ε)
(expt fz 3.0)
- (/ (- (* 116 fz) 16) color-lab-κ))))
+ (/ (- (* 116 fz) 16) color-cie-κ))))
(list (* xr Xr) ; X
(* yr Yr) ; Y
(* zr Zr))))) ; Z
-(defun rgb->lab (red green blue)
+(defun color-rgb->lab (red green blue)
"Converts RGB to CIE L*a*b*."
- (apply 'xyz->lab (rgb->xyz red green blue)))
+ (apply 'color-xyz->lab (color-rgb->xyz red green blue)))
-(defun rgb->normalize (color)
+(defun color-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)
+(defun color-lab->rgb (L a b)
"Converts CIE L*a*b* to RGB."
- (apply 'xyz->rgb (lab->xyz L a b)))
+ (apply 'color-xyz->rgb (color-lab->xyz L a b)))
-(defun color-lab-ciede2000 (color1 color2 &optional kL kC kH)
+(defun color-cie-de2000 (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
(expt (/ ΔH′ (* Sh kH)) 2.0)
(* Rt (/ ΔC′ (* Sc kC)) (/ ΔH′ (* Sh kH)))))))))
-(provide 'color-lab)
+(provide 'color)
-;;; color-lab.el ends here
+;;; color.el ends here
;;; Code:
-(require 'color-lab)
+(require 'color)
(defgroup shr-color nil
"Simple HTML Renderer colors"
new background color will not be computed. Only the foreground
color will be adapted to be visible on BG."
;; Convert fg and bg to CIE Lab
- (let ((fg-norm (rgb->normalize fg))
- (bg-norm (rgb->normalize bg)))
+ (let ((fg-norm (color-rgb->normalize fg))
+ (bg-norm (color-rgb->normalize bg)))
(if (or (null fg-norm)
(null bg-norm))
(list bg fg)
- (let* ((fg-lab (apply 'rgb->lab fg-norm))
- (bg-lab (apply 'rgb->lab bg-norm))
+ (let* ((fg-lab (apply 'color-rgb->lab fg-norm))
+ (bg-lab (apply 'color-rgb->lab bg-norm))
;; Compute color distance using CIE DE 2000
- (fg-bg-distance (color-lab-ciede2000 fg-lab bg-lab))
+ (fg-bg-distance (color-cie-de2000 fg-lab bg-lab))
;; Compute luminance distance (substract L component)
(luminance-distance (abs (- (car fg-lab) (car bg-lab)))))
(if (and (>= fg-bg-distance shr-color-visible-distance-min)
bg
(apply 'format "#%02x%02x%02x"
(mapcar (lambda (x) (* (max (min 1 x) 0) 255))
- (apply 'lab->rgb bg-lab))))
+ (apply 'color-lab->rgb bg-lab))))
(apply 'format "#%02x%02x%02x"
(mapcar (lambda (x) (* (max (min 1 x) 0) 255))
- (apply 'lab->rgb fg-lab))))))))))
+ (apply 'color-lab->rgb fg-lab))))))))))
(provide 'shr-color)