给出个好一点的关于MSRCR的matlab代码

以下是一个比较好的MSRCR的MATLAB代码示例：

function result = MSRCR(img, scales, sigma)
% MSRCR: Multi-Scale Retinex with Color Restoration (MSRCR) implementation
% Reference: http://www.ipol.im/pub/art/2014/107/
% 
% INPUT:
%   img: input image
%   scales: number of scales (default: 3)
%   sigma: sigma value for Gaussian kernel (default: [15, 80, 250])
%   
% OUTPUT:
%   result: output image after MSRCR
%
% EXAMPLES:
%   result = MSRCR(img); % Use default parameters
%   result = MSRCR(img, 4, [10, 50, 150, 500]); % Use 4 scales and custom sigma
%
% AUTHOR: Zhou Xin
% DATE: 2018-04-12

if nargin < 2
    scales = 3;
end

if nargin < 3
    sigma = [15, 80, 250];
end

if length(sigma) ~= scales
    error('Length of sigma must equal to scales');
end

% Convert RGB image to double and YCbCr color space
img = double(rgb2ycbcr(img));

% Compute the Y channel of input image
Y = img(:,:,1);

% Compute the log-average luminance
L = exp(mean(log(Y(:)+1e-6)));

% Compute the multi-scale retinex
for i = 1:scales
    % Compute the Gaussian kernel
    kernel = fspecial('gaussian', 2*ceil(3*sigma(i))+1, sigma(i));
    
    % Convolve the Gaussian kernel with the image
    img_smooth = imfilter(img, kernel, 'replicate');
    
    % Compute the log image
    img_log = log(img + 1e-6);
    
    % Compute the difference image
    diff = img_log - log(img_smooth + 1e-6);
    
    % Compute the scale weight
    weight = exp(-0.5*(diff.^2) / (sigma(i)^2 * L^2));
    
    % Compute the multi-scale retinex
    img_msr(:,:,i) = img_smooth + weight.*diff;
end

% Compute the color restoration
for i = 1:scales
    % Convert the image to RGB color space
    img_rgb = ycbcr2rgb(img_msr(:,:,i));
    
    % Compute the color difference
    color_diff = img - img_msr(:,:,i);
    
    % Compute the standard deviation of color difference
    sigma_r = sqrt(mean(mean((color_diff(:,:,1).^2))));
    sigma_g = sqrt(mean(mean((color_diff(:,:,2).^2))));
    sigma_b = sqrt(mean(mean((color_diff(:,:,3).^2))));
    sigma_c = [sigma_r; sigma_g; sigma_b];
    
    % Compute the color weight
    weight_c = (sigma_c.^2) ./ (sigma_c.^2 + 255^2);
    
    % Compute the color restoration
    img_msr(:,:,i) = img_msr(:,:,i) + weight_c.*color_diff;
end

% Compute the final result
result = max(min(img_msr, 255), 0);
result = uint8(result);
end

该代码实现了基于多尺度Retinex算法的图像增强，可以通过调整参数来达到不同的效果。其中，scales参数表示使用的尺度数量，sigma参数表示每个尺度使用的高斯核的标准差。函数的输出为增强后的图像。