K-means Fixed Clustering Code [Kao-v1]

% Comment: Classify the Colors in 'a*b*' Space Using Fixed K-Means Clustering
    ab = double(rgb_he(:,:,2:3));
    ab_all_band = double(rgb_he(:,:,2:3));
    nrows = size(ab,1);
    ncols = size(ab,2);
    ab = reshape(ab,nrows*ncols,2);

    nColors = 3;
    [cluster_idx, cluster_center] = kmeans(ab,nColors, ...
                                    'Replicates',1, ...
                                    'Options',opts, ...
                                    'start',[118 143; 127 140; 133 127]);
% Define A*B color on each cluster. (this example have 3 cluster)