색상 차이 공식

1 개요

color difference, color distance

$\mathrm{\Delta }E$

색상 차이, 색상 거리, 색상 차이 계산식, 색상 차이 계산 공식, 색상 차이 계산 방법

• 두 색상의 차이
• 두 색이 색공간에서 떨어진 거리

2 CIE76

DeltaE_CIE76 구현 문서를 참고하십시오.

• Lab 색공간에서의 거리

$\mathrm{\Delta }{E}_{76}^{\ast }=\sqrt{(L_2^{\ast }-L_1^{\ast }{)}^2+(a_2^{\ast }-a_1^{\ast }{)}^2+(b_2^{\ast }-b_1^{\ast }{)}^2}$

3 CIE94

DeltaE_CIE94 구현 문서를 참고하십시오.

• CIELCH 개념에 따른 보정

$\mathrm{\Delta }{E}_{94}^{\ast }=\sqrt{{\left(\frac{\mathrm{\Delta }{L}^{\ast }}{k_L{S}_L}\right)}^2+{\left(\frac{\mathrm{\Delta }{C}_{ab}^{\ast }}{k_C{S}_C}\right)}^2+{\left(\frac{\mathrm{\Delta }{H}_{ab}^{\ast }}{k_H{S}_H}\right)}^2}$

여기서:

$\mathrm{\Delta }{L}^{\ast }=L_1^{\ast }-L_2^{\ast }$

$C_1^{\ast }=\sqrt{{a_1^{\ast }}^2+{b_1^{\ast }}^2}$

$C_2^{\ast }=\sqrt{{a_2^{\ast }}^2+{b_2^{\ast }}^2}$

$\mathrm{\Delta }{C}_{ab}^{\ast }=C_1^{\ast }-C_2^{\ast }$

$\mathrm{\Delta }{H}_{ab}^{\ast }=\sqrt{{\mathrm{\Delta }{E}_{ab}^{\ast }}^2-{\mathrm{\Delta }{L}^{\ast }}^2-{\mathrm{\Delta }{C}_{ab}^{\ast }}^2}=\sqrt{{\mathrm{\Delta }{a}^{\ast }}^2+{\mathrm{\Delta }{b}^{\ast }}^2-{\mathrm{\Delta }{C}_{ab}^{\ast }}^2}$

$\mathrm{\Delta }{a}^{\ast }=a_1^{\ast }-a_2^{\ast }$

$\mathrm{\Delta }{b}^{\ast }=b_1^{\ast }-b_2^{\ast }$

$S_L=1$

$S_C=1+K_1{C}_1^{\ast }$

$S_H=1+K_2{C}_1^{\ast }$

단,

$k_L=1,K_1=0.045,K_2=0.015$ (그래픽 아트의 경우)

$k_L=2,K_1=0.048,K_2=0.014$ (직물의 경우)

4 CIE2000

DeltaE_CIE2000 구현 문서를 참고하십시오.

• 5가지 보정

275˚ 부근 색조 회전($R_T$), 중성색 보정($\mathrm{\Delta }{L}^{\prime },\mathrm{\Delta }{C}^{\prime },\mathrm{\Delta }{H}^{\prime }$)

밝기 보정($S_L$), 채도 보정($S_C$), 색조 보정($S_H$)

$\mathrm{\Delta }{E}_{00}^{\ast }=\sqrt{{\left(\frac{\mathrm{\Delta }{L}^{\prime }}{k_L{S}_L}\right)}^2+{\left(\frac{\mathrm{\Delta }{C}^{\prime }}{k_C{S}_C}\right)}^2+{\left(\frac{\mathrm{\Delta }{H}^{\prime }}{k_H{S}_H}\right)}^2+R_T\frac{\mathrm{\Delta }{C}^{\prime }}{k_C{S}_C}\frac{\mathrm{\Delta }{H}^{\prime }}{k_H{S}_H}}$

$\mathrm{\Delta }{L}^{\prime }=L_2^{\ast }-L_1^{\ast }$

$\overline{L}=\frac{L_1^{\ast }+L_2^{\ast }}{2}$, $\overline{C}=\frac{C_1^{\ast }+C_2^{\ast }}{2}$

$a_1^{\prime }=a_1^{\ast }+\frac{a_1^{\ast }}{2}(1-\sqrt{\frac{{\overline{C}}^7}{{\overline{C}}^7+{25}^7}})$, $a_2^{\prime }=a_2^{\ast }+\frac{a_2^{\ast }}{2}(1-\sqrt{\frac{{\overline{C}}^7}{{\overline{C}}^7+{25}^7}})$

${\overline{C}}^{\prime }=\frac{C_1^{\prime }+C_2^{\prime }}{2}$, $\mathrm{\Delta }{C}^{\prime }=C_2^{\prime }-C_1^{\prime }$

$C_1^{\prime }=\sqrt{a_1^{{}^{\prime 2}}+b_1^{{\ast }^2}}$, $C_2^{\prime }=\sqrt{a_2^{{}^{\prime 2}}+b_2^{{\ast }^2}}$

$h_1^{\prime }=\text{atan2}(b_1^{\ast },a_1^{\prime })\mathrm{mod}{360}^{\circ }$, $h_2^{\prime }=\text{atan2}(b_2^{\ast },a_2^{\prime })\mathrm{mod}{360}^{\circ }$

$\mathrm{\Delta }{h}^{\prime }=\{\begin{array}{ll}{h}_2^{\prime }-h_1^{\prime }& |h_1^{\prime }-h_2^{\prime }|\le {180}^{\circ }\\ h_2^{\prime }-h_1^{\prime }+{360}^{\circ }& |h_1^{\prime }-h_2^{\prime }|>{180}^{\circ },h_2^{\prime }\le h_1^{\prime }\\ h_2^{\prime }-h_1^{\prime }-{360}^{\circ }& |h_1^{\prime }-h_2^{\prime }|>{180}^{\circ },h_2^{\prime }>h_1^{\prime }\end{array}$

$\mathrm{\Delta }{H}^{\prime }=2\sqrt{C_1^{\prime }{C}_2^{\prime }}\sin (\mathrm{\Delta }{h}^{\prime }/2)$

${\overline{H}}^{\prime }=\{\begin{array}{ll}(h_1^{\prime }+h_2^{\prime }+{360}^{\circ })/2& |h_1^{\prime }-h_2^{\prime }|>{180}^{\circ }\\ (h_1^{\prime }+h_2^{\prime })/2& |h_1^{\prime }-h_2^{\prime }|\le {180}^{\circ }\end{array}$

$T=1-0.17\cos ({\overline{H}}^{\prime }-{30}^{\circ })+0.24\cos (2{\overline{H}}^{\prime })$$+0.32\cos (3{\overline{H}}^{\prime }+6^{\circ })-0.20\cos (4{\overline{H}}^{\prime }-{63}^{\circ })$

$S_L=1+\frac{0.015{(\overline{L}-50)}^2}{\sqrt{20+{(\overline{L}-50)}^2}}{S}_C=1+0.045{\overline{C}}^{\prime }{S}_H=1+0.015{\overline{C}}^{\prime }T$

$R_T=-2\sqrt{\frac{{\overline{C}}^{\prime 7}}{{\overline{C}}^{\prime 7}+{25}^7}}\sin [{60}^{\circ }\cdot \exp (-{\left[\frac{{\overline{H}}^{\prime }-{275}^{\circ }}{{25}^{\circ }}\right]}^2)]$

5 같이 보기

• DeltaE_CIE76 구현
• DeltaE_CIE94 구현
• DeltaE_CIE2000 구현
• CEILAB
• 색상 변환
• 색상
• 차이
• 거리

6 참고

• http://en.wikipedia.org/wiki/Color_difference