watershed_seg.m

function new_grain = watershed_seg(image_g,bw)
close all;
%image_g =imread('test.jpg');
%image_g_r=image_g(:,:,1);
image_g_g=image_g(:,:,2);
image_g_b=image_g(:,:,3);
imshow(bw);
bw1= bw;
D=bwdist(~bw1);
figure ;
imshow(D,[],'InitialMagnification','fit');
title('Distance transform of ~bw');
D = -D;
D(~bw1) = -Inf;
D = imhmin(D,3); 
D=imfill(D,'holes');
%D=imimposemin(D, fg|~bg);
L = watershed(D);
rgb = label2rgb(L,'jet',[.5 .5 .5]);
%figure;
%imshow(rgb,'InitialMagnification','fit')
%title('Watershed transform of D')

bw1(L==0)=0;
se = strel('disk', 10);
bw1 = imopen(bw1,se);
%figure;
imshow(bw1);
cc1 = bwconncomp(bw1, 8);
graindata = regionprops(cc1,'basic');
grain_areas = [graindata.Area];
segmented_grain ={};
new_grain={};
new_grain1={};
new_grain2={};
new_grain3={};
t=1;
p=1;
for num_grain=1:cc1.NumObjects
    A = cc1.PixelIdxList{num_grain};
	Ht = size(bw1,1);
	A_x = fix(A/Ht);
	A_y = rem(A,Ht);
	d_x = max(A_x) - min(A_x) + 1;
	d_y = max(A_y) - min(A_y) + 1;
	sz = size(A);
	Ayy = A_y - min(A_y) ;
	Axx = A_x - min(A_x) ;

	A_n = Axx*d_y + Ayy + 1;
    
	new_grain1{num_grain} = uint8(zeros(d_y, d_x)); %this is assuming a grayscale image
    new_grain1{num_grain}(A_n)=image_g_r(A);
    new_grain1{num_grain}=padarray(new_grain1{num_grain},[2,2]);
    new_grain2{num_grain} = uint8(zeros(d_y, d_x)); %this is assuming a grayscale image
    new_grain2{num_grain}(A_n)=image_g_g(A);
    new_grain2{num_grain}=padarray(new_grain2{num_grain},[2,2]);
    new_grain3{num_grain} = uint8(zeros(d_y, d_x)); %this is assuming a grayscale image
    new_grain3{num_grain}(A_n)=image_g_b(A);
    new_grain3{num_grain}=padarray(new_grain3{num_grain},[2,2]);
    new_grain{num_grain}=cat(3,new_grain1{num_grain},new_grain2{num_grain},new_grain3{num_grain});
    %imshow(new_grain{num_grain});
    if grain_areas(num_grain) > 500
       segmented_grain{t}=new_grain{num_grain};
        if p>50
           p=1;
           figure;
           subplot(10,5,p);
       else 
           subplot(10,5,p);
       end
        imshow(new_grain{num_grain},'InitialMagnification','fit');
        title(num2str(t));
        t=t+1;
        p=p+1;
    end
	
end

%rgb = label2rgb(L,'jet',[.5 .5 .5]);
%figure
%imshow(rgb,'InitialMagnification','fit')
%title('Watershed transform of D')