src/color-difference.lisp @ dc2c9931b634
SICP streams
author |
Steve Losh <steve@stevelosh.com> |
date |
Sun, 04 Sep 2016 22:20:37 +0000 |
parents |
56edfdd18674 |
children |
184af4c4e8fc |
(in-package #:sand.color-difference)
; https://en.wikipedia.org/wiki/Color_difference
(defparameter *c1* (make-cie-rgb-color 0.0 1.0 1.0))
(defparameter *c2* (make-cie-rgb-color 0.1 1.0 1.0))
(defparameter *c3* (make-cie-rgb-color 0.7 1.0 1.0))
(defun cie-76-distance (c1 c2)
(multiple-value-bind (l1 a1 b1) (cie-lab-color-coordinates c1)
(multiple-value-bind (l2 a2 b2) (cie-lab-color-coordinates c2)
(sqrt (+ (square (- l2 l1))
(square (- a2 a1))
(square (- b2 b1)))))))
; (cie-76-distance *c1* *c2*)
; (defparameter *c* )
; (cie-lab-color-coordinates (make-cie-xyz-color 0 0 0))