如何在matlab中使用k均值聚类获得准确的聚类

Question

我正在做一个关于植物病害检测的项目。我需要从叶子图像中提取患病部分，但我无法使用 k-means 准确分离出患病区域。具体来说，叶子的其余部分在图像上可见，患病部分已被分割。这是原始图像和提取病变部分后的图像：original image image after separating diseased parts

这是我写的代码

b=imread('12.jpeg');
G=fspecial('gaussian',[200 250],1);
Ig=imfilter(b,G,'same');
figure,imshow(Ig);
conversionform = makecform('srgb2lab');
lab_img = applycform(Ig,conversionform);
figure,imshow(lab_img);
ab = double(lab_img(:,:,2:3));
nrows = size(ab,1);
ncols = size(ab,2);
ab = reshape(ab,nrows*ncols,2);
nColors = 2;
[cluster_idx, cluster_center] = kmeans(ab,nColors,'distance','sqEuclidean',    ...,
                                  'Replicates',3);
pixel_labels = reshape(cluster_idx,nrows,ncols);
figure, imshow(pixel_labels,[]), title('image labeled by cluster index');
segmented_images = cell(1,3);
rgb_label = repmat(pixel_labels,[1 1 3]);
for k = 1:nColors
    color = lab_img;
    color(rgb_label ~= k) = 0;
    segmented_images{k} = color;
end
figure, imshow(segmented_images{1}), title('objects in cluster 1');
figure, imshow(segmented_images{2}), title('objects in cluster 2');
e=segmented_images{1};
figure,imshow(e);
conversionform = makecform('lab2srgb');
new_image=applycform(e,conversionform);
figure,imshow(new_image);

我想使用 K 均值聚类仅提取病变区域。如果有人可以帮助我，我将不胜感激。我正在使用 matlab 2009a.

Answer 1

这是一个更正后的代码，可以满足您的期望：

function segmented_img = leaf_segmentation( original_img, nclusters )

    original_img = im2double(original_img);
    smoothed_img = imgaussfilt(original_img,1);

    conversionform = makecform('srgb2lab');
    lab_img = applycform(smoothed_img,conversionform);

    ab_img = lab_img(:,:,2:3);
    [nrows,ncols,~] = size(ab_img);
    ab_img = reshape(ab_img,nrows*ncols,2);

    cluster_idx = kmeans(ab_img,nclusters,'distance','sqEuclidean','Replicates',3);
    cluster_img = reshape(cluster_idx,nrows,ncols);

    %figure, imagesc(cluster_img), title('Clustering results');

    segmented_img = cell(1,nclusters);
    for k = 1:nclusters
        segmented_img{k} = bsxfun( @times, original_img, cluster_img == k );
    end

end

您可以像这样调用它并可视化结果：

segmented = leaf_segmentation( original, 3 );

figure;
subplot(1,3,1), imshow(segmented{1}), title('Cluster 1');
subplot(1,3,2), imshow(segmented{2}), title('Cluster 2');
subplot(1,3,3), imshow(segmented{3}), title('Cluster 3');

请注意，集群的顺序可能会有所不同。您可以先验地订购它们，知道叶子应该大部分是 green/yellow，并且背景应该大部分是黑色。

如何在matlab中使用k均值聚类获得准确的聚类

How to get accurate clusters using k-means clustering in matlab

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