Make clearer color segmentation.

Hello!! I am a beginner. And I try color segmentation.

two picture is before and after color segmentation. As you see, too many noise and hole are after segmentation.

I just replicate the method which mathwork suppy.(imquantize, Color-Based Segmentation Using K-Means Clustering)

I don't know where is problem.(is code for quantization and clustering wrong? / is color of map poor?) How can I make clear the result?

Are there other good quantization or clustering method?

I know my question is very ambiguous, not concrete. I just want a little hint for better job.

Please advise any suggestion for my work.

function Y2=extcontq(X)
%for color map
%you must control ncolor value for extract clear contour

ncolor=input('ncolor(generally 4) : ');

%Quantization of color image
threshRGB=multithresh(X,7);
threshForPlanes=zeros(3,7);
for i=1:3
  thresForPlane(i,:)=multithresh(X(:,:,i),7);
end
value = [0 threshRGB(2:end) 255];
quantRGB=imquantize(X, threshRGB, value);

%clustering
cform=makecform('srgb2lab');
lab_A=applycform(X,cform);
ab=double(lab_A(:,:,2:3));
nrows=size(ab,1);
ncols=size(ab,2);
ab=reshape(ab,nrows*ncols,2);
[cluster_idx,cluster_center]=kmeans(ab,ncolor,'distance','sqEuclidean','Replicates',3);
pixel_label=reshape(cluster_idx,nrows,ncols);
%imshow(pixel_label,[])

%Segmentation
segmented_image = cell(1,3);
rgb_label=repmat(pixel_label,[1 1 3]);

for k=1:ncolor
color=X;
color(rgb_label ~=k)=0;
segmented_image{k}=color;
end

c=1;
while c==1
  for i=1:ncolor
      imshow(segmented_image{i})
      q=input('Do you want this data?(Y=1/N=0)');

        if i==ncolor
            if q==0
                c=input('Return? [Y=1/N=0]');
            end
        end

        if q==1
            Y1=segmented_image{i};
            c=0;
            close all;
            break
        end

    close all;
    end
  end

%binary
Y2=binary_my(Y1);

imshow(Y2);

d=input('Do you want reverse BW?[Y=1/N=0]');

if d==1
  Y2=imcomplement(Y2);
end
close all

Y=Y2;
imshow(Y2);

[Walter Roberson]

Which information are you trying to extract?

[Kwanghun Choi]

Contour line. I want to extract contour line.