matlab - Separate connected objects and single objects from an image -

i working on image in matlab shown in link http://lyremjeni.files.wordpress.com/2013/08/tocleanblobs.jpg

i want separate connected/grouped cell blobs , single cell blobs image , display them in separate figures. kindly suggest how can achieve separation.

here 2 solutions use, 1st 1 using bwconncomp finds connected elements in binary image, , 2nd 1 using imfindcircles, believe or not finds circles! therefore in instances objects detect not circles 1st solution preferred.

i prefer first one, discriminates between single circles , clusters of circles, asked, whereas method using imfindcircles rather useful identifying individual circles, not clusters. here code:

1- bwconncomp

clear close clc  = imread('circles.jpg'); bw = im2bw(a); %// convert binary threshold of 0.5.   cc = bwconncomp(bw); %// find connected components. 

this cc looks like, i.e. structure couple fields:

cc =       connectivity: 8        imagesize: [256 256]       numobjects: 15     pixelidxlist: {1x15 cell} 

as see there 15 objects detected.

now loop throught objects , plot/draw them:

bw2 = zeros(size(bw)); %// create dummy image display purposes. imshow(bw2) hold on  k = 1:cc.numobjects %// loop through each object , plot in white. can create individual figures each object.      pixid = cc.pixelidxlist{k}; %// simpler understand      if size(pixid,1) ==1 %// if 1 row, don't consider.                 continue     else     bw2(pixid) = 255;  %figure(k) %// uncomment if want individual figures.     imshow(bw2)     pause(.5) %// display purposes.     end end 

if run code see creates 1 figure; demonstration if want each object in figure add figure in loop noted create one.

2- imfindcircles

here principle simple, algorithm detects circles , stores radius , center coordinates. it's quite easy plot/crop them them individually. said not detect clusters of circles, thought know anyway.

here create figure each circle detected.

a = imread('circles.jpg'); [centers, radii, ~] = imfindcircles(a,[5 25],'sensitivity',.95,'objectpolarity','bright');  a_crop = cell(1,numel(radii)); k =1:numel(radii)      %// since imcrop requires cropping rectangle, need fin x , y coordinates of lower-left corner, width , height of rectangle.      x = centers(k,1);     y = centers(k,2);     r = radii(k);       a_crop{k} = imcrop(a,[x-r y-r 2*r 2*r]); %// [x y width height]    imshow(a_crop) %// new figure    pause(0.5)  end 

if want see circles outlined, can use this:

imshow(a);  hold on   viscircles(centers, radii,'edgecolor','b');  hold off 

giving following: