how can i create background black in rgb image?

Question

sobana on 29 Aug 2014

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https://nl.mathworks.com/matlabcentral/answers/152770-how-can-i-create-background-black-in-rgb-image

Answered: Image Analyst on 15 Dec 2014

segmentation of cervical cancer.pdf

i need to segment the cervical cell image...i decided to segment using watershed segmentation algorithm...in this segmentation types i have to separate cell nuclei from cytoplasm...i tried many types but i could not get output my coding and images are given

clc; clear all; close all; he=imread('E:\ME project\pap smear image.jpg'); w =imresize(he,[290 290]); imshow(w);

h = makecform('srgb2lab'); lab_he = applycform(w,h);

l = lab_he(:,:,1); figure, imshow(l), title('l'); % Converting into double % l= double(lab_he(:,:,2:3)); % % obtaining rows and columns of transformed image % nrows = size(l,1); ncols = size(l,2); % % Reshaping image taking each value column wise % ab= reshape(l,nrows*ncols,2); % No of clusters to be created with five iterations % nColors = 1; [cluster_idx, cluster_center] = kmeans(ab,nColors,'distance','sqEuclidean','Replicates',1); % Reshaping and showing the clusters % pixel_labels = reshape(cluster_idx,nrows,ncols); imshow(pixel_labels,[]), title('image labeled by cluster index'); % % creating five element array % segmented_images = cell(1); % Creating tiles for three different colors % rgb_label = repmat(pixel_labels,[1 1 3]); % Assigning clustered objects to array(segmented_image) % for k = 1:nColors color = w; color(rgb_label ~= k) = 0; segmented_images{k} = color; end %displaying different cluster objects % imshow(segmented_images{1}), title('objects in cluster 1');

 % Evaluating mean of all cluster centers %
 mean_cluster_value = mean(cluster_center,2);
 % Sorting the mean cluster array and storing sorted index in idx % 
 [tmp, idx] = sort(mean_cluster_value);
 n1_cluster_num = idx(1);
 l = lab_he(:,:,1);
 n1_idx = find(pixel_labels == n1_cluster_num);
 L_n1 = l(n1_idx);
 is_light_n1 = im2bw(L_n1,graythresh(L_n1));
 nuclei_labels = repmat(uint8(0),[nrows ncols]);
 nuclei_labels(n1_idx(is_light_n1==false)) = 1;
 nuclei_labels = repmat(nuclei_labels,[1 1 3]);
 n1_nuclei = w;
 n1_nuclei(nuclei_labels ~= 1) = 0;
 imshow(n1_nuclei), title('n1 nuclei');

h = makecform('srgb2lab'); lab = applycform(n1_nuclei,h); l1 = lab(:,:,1); figure, imshow(l1), title('l1'); I3 = imadjust(l1); hy = fspecial('sobel'); hx = hy'; Iy = imfilter(double(I3), hy, 'replicate'); Ix = imfilter(double(I3), hx, 'replicate'); gradmag = sqrt(Ix.^2 + Iy.^2); figure, imshow(gradmag,[]), title('Gradient magnitude (gradmag)')

W = imregionalmax(gradmag); figure, imshow(W), title('Regional Minima in Original Image');

L=watershed(gradmag); wr=L==0; figure,imshow(wr)

q=imadjust(gradmag); d = edge(q,'canny',.19);

ds = bwareaopen(d,15);

d1=im2double(l1); iout= d1; BW= ds; iout(:,:,1) = iout; %# Initialize red color plane iout(:,:,2) = iout(:,:,1); %# Initialize green color plane iout(:,:,3) = iout(:,:,1); %# Initialize blue color plane iout(:,:,1) = min(iout(:,:,1) + BW, 1); %# Add edges to green color plane iout(:,:,1) = min(iout(:,:,1) + BW, 1); %# Add edges to blue color plane figure, imshow(iout), title('iout');