how to find rounded object using circular hough transform ?

i am getting circles that showing the rounded objects in the image but along with that i am also getting the circles where the rounded object really not found. how to avoid this and to get only the circles around the rounded object or dots or blots which is my output (candidate region to be found).

Answer 1

[Image Analyst]

Try imfindcircles - it uses that method. Here's a demo by Brett that uses it: http://www.mathworks.com/matlabcentral/fileexchange/34365-findcirclesgui

[kalaivaani]

but i used same imfindcircles