matlab计算颜色距离代码示例

以下是使用MATLAB计算颜色距离的示例代码：

%% 读入图像并转换为LAB颜色空间
img = imread('testimage.jpg');
img = imresize(img, [256, 256]); % 调整图像大小以加快计算速度
lab = rgb2lab(img);

%% 选择两个像素进行颜色距离计算
pixel1 = lab(50,50,:);
pixel2 = lab(200,200,:);

%% 计算欧几里德距离
dist_euc = sqrt(sum((pixel1 - pixel2).^2));

%% 计算CIEDE2000距离
dist_ciede2000 = ciede2000(pixel1, pixel2);

%% 打印结果
disp(['欧几里德距离：' num2str(dist_euc)]);
disp(['CIEDE2000距离：' num2str(dist_ciede2000)]);

%% CIEDE2000距离计算函数
function [ delta_e ] = ciede2000( lab1, lab2 )
%CIEDE2000 Calculate the distance between two LAB colors in CIEDE2000 color space

% Constants
k_L = 1;
k_C = 1;
k_H = 1;

l1 = lab1(1);
a1 = lab1(2);
b1 = lab1(3);
l2 = lab2(1);
a2 = lab2(2);
b2 = lab2(3);

% Calculate C1 and C2
C1 = sqrt(a1^2 + b1^2);
C2 = sqrt(a2^2 + b2^2);

% Calculate average C
C_avg = (C1 + C2) / 2;

% Calculate G
G = 0.5 * (1 - sqrt(C_avg^7 / (C_avg^7 + 25^7)));

% Calculate a'1 and a'2
a1_prime = (1 + G) * a1;
a2_prime = (1 + G) * a2;

% Calculate C'1 and C'2
C1_prime = sqrt(a1_prime^2 + b1^2);
C2_prime = sqrt(a2_prime^2 + b2^2);

% Calculate h'1 and h'2
h1_prime = atan2(b1, a1_prime);
h2_prime = atan2(b2, a2_prime);

% Deal with hue wrap-arounds
if abs(h1_prime - h2_prime) > pi
if h2_prime <= h1_prime
h2_prime = h2_prime + 2*pi;
else
h1_prime = h1_prime + 2*pi;
end
end

% Calculate delta_L_prime, delta_C_prime and delta_H_prime
delta_L_prime = l2 - l1;
delta_C_prime = C2_prime - C1_prime;
delta_h_prime = h2_prime - h1_prime;
delta_h_prime = delta_h_prime - 2*pi*fix(delta_h_prime/(2*pi));
delta_H_prime = 2*sqrt(C1_prime*C2_prime)*sin(delta_h_prime/2);

% Calculate L'avg, C'avg, h'avg
L_avg = (l1 + l2) / 2;
C_avg_prime = (C1_prime + C2_prime) / 2;

h_avg_prime = h1_prime + h2_prime;
if abs(h1_prime - h2_prime) > pi
if h_avg_prime < 2*pi
h_avg_prime = h_avg_prime + 2*pi;
else
h_avg_prime = h_avg_prime - 2*pi;
end
end
h_avg_prime = h_avg_prime / 2;

% Calculate delta_L, delta_C, delta_H
delta_L = delta_L_prime;
delta_C = delta_C_prime;
delta_H = delta_H_prime;
if C1_prime * C2_prime == 0
delta_H = 0;
else
if abs(h1_prime - h2_prime) <= pi
delta_H = delta_H;
elseif h_avg_prime < pi
delta_H = delta_H + 2*pi;
elseif h_avg_prime >= pi
delta_H = delta_H - 2*pi;
end
end

% Calculate L* C* H*
L_star = L_avg;
C_star = C_avg_prime;
H_star = h_avg_prime;
if C1_prime * C2_prime == 0
H_star = h1_prime + h2_prime;
if abs(h1_prime - h2_prime) > pi
if H_star < 2*pi
H_star = H_star + 2*pi;
else
H_star = H_star - 2*pi;
end
end
H_star = H_star / 2;
else
H_star = (h1_prime + h2_prime) / 2;
end

% Calculate T, S, C_ph, H_ph
T = 1 - 0.17*cos(H_star - pi/6) + 0.24*cos(2*H_star) + 0.32*cos(3*H_star+pi/30) - 0.2*cos(4*H_star-63*pi/180);
S = 1 + (0.015*(L_star - 50)^2) / sqrt(20 + (L_star - 50)^2);
C_ph = sqrt(C_star^7 / (C_star^7 + 25^7));
H_ph = H_star - pi/3 * exp(-((H_star - pi/3) / (2*pi/3))^2);

% Calculate delta_theta, R_C, R_T
delta_theta = pi/6 * exp(-((180/pi*H_ph - 275) / 25)^2);
R_C = 2*C_ph^7 / (C_ph^7 + 25^7);
R_T = -sin(2*delta_theta) * R_C;

% Calculate delta_E00
delta_E00 = sqrt((delta_L / (k_L*S))^2 + (delta_C / (k_C*S))^2 + (delta_H / (k_H*S))^2 + R_T*(delta_C / (k_C*S))*(delta_H / (k_H*S)));

end